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  • Unable to logon to vpn

    - by nitin pande
    My openvpn client log file- The interesting bit: Tue Oct 26 12:32:49 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 12:32:49 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 12:32:49 2010 TCP/UDP: Closing socket The rest of the log just in case: Tue Oct 26 12:32:35 2010 OpenVPN 2.0.9 Win32-MinGW [SSL] [LZO] built on Oct 1 2006 Tue Oct 26 12:32:48 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 12:32:48 2010 Control Channel Authentication: using 'ta.key' as a OpenVPN static key file Tue Oct 26 12:32:48 2010 Outgoing Control Channel Authentication: Using 160 bit message hash 'SHA1' for HMAC authentication Tue Oct 26 12:32:48 2010 Incoming Control Channel Authentication: Using 160 bit message hash 'SHA1' for HMAC authentication Tue Oct 26 12:32:48 2010 LZO compression initialized Tue Oct 26 12:32:48 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 12:32:48 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 12:32:48 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 12:32:48 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 12:32:48 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 12:32:48 2010 TCP connection established with 67.228.223.12:3389 Tue Oct 26 12:32:48 2010 TCPv4_CLIENT link local: [undef] Tue Oct 26 12:32:48 2010 TCPv4_CLIENT link remote: 67.228.223.12:3389 Tue Oct 26 12:32:49 2010 TLS: Initial packet from 67.228.223.12:3389, sid=bd5f79fe 8475497f Tue Oct 26 12:32:49 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 12:32:49 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 12:32:49 2010 TCP/UDP: Closing socket Tue Oct 26 12:32:49 2010 SIGUSR1[soft,tls-error] received, process restarting Tue Oct 26 12:32:49 2010 Restart pause, 5 second(s) Tue Oct 26 12:32:54 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 12:32:54 2010 Re-using SSL/TLS context Tue Oct 26 12:32:54 2010 LZO compression initialized Tue Oct 26 12:32:54 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 12:32:54 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 12:32:54 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 12:32:54 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 12:32:54 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 12:32:54 2010 TCP connection established with 67.228.223.12:3389 Tue Oct 26 12:32:54 2010 TCPv4_CLIENT link local: [undef] Tue Oct 26 12:32:54 2010 TCPv4_CLIENT link remote: 67.228.223.12:3389 Tue Oct 26 12:32:54 2010 TLS: Initial packet from 67.228.223.12:3389, sid=1643b931 ce240d5f Tue Oct 26 12:32:54 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 12:32:54 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 12:32:54 2010 TCP/UDP: Closing socket Tue Oct 26 12:32:54 2010 SIGUSR1[soft,tls-error] received, process restarting Tue Oct 26 12:32:54 2010 Restart pause, 5 second(s) Tue Oct 26 12:32:59 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 12:32:59 2010 Re-using SSL/TLS context Tue Oct 26 12:32:59 2010 LZO compression initialized Tue Oct 26 12:32:59 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 12:32:59 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 12:32:59 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 12:32:59 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 12:32:59 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 12:33:00 2010 TCP connection established with 67.228.223.12:3389 Tue Oct 26 12:33:00 2010 TCPv4_CLIENT link local: [undef] Tue Oct 26 12:33:00 2010 TCPv4_CLIENT link remote: 67.228.223.12:3389 Tue Oct 26 12:33:00 2010 TLS: Initial packet from 67.228.223.12:3389, sid=cd439fb2 d625ca0d Tue Oct 26 12:33:00 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 12:33:00 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 12:33:00 2010 TCP/UDP: Closing socket Tue Oct 26 12:33:00 2010 SIGUSR1[soft,tls-error] received, process restarting Tue Oct 26 12:33:00 2010 Restart pause, 5 second(s) Tue Oct 26 12:33:05 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 12:33:05 2010 Re-using SSL/TLS context Tue Oct 26 12:33:05 2010 LZO compression initialized Tue Oct 26 12:33:05 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 12:33:05 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 12:33:05 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 12:33:05 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 12:33:05 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 12:33:06 2010 TCP connection established with 67.228.223.12:3389 Tue Oct 26 12:33:06 2010 TCPv4_CLIENT link local: [undef] Tue Oct 26 12:33:06 2010 TCPv4_CLIENT link remote: 67.228.223.12:3389 Tue Oct 26 12:33:06 2010 TLS: Initial packet from 67.228.223.12:3389, sid=28f0cb87 69c90cde Tue Oct 26 12:33:06 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 12:33:06 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 12:33:06 2010 TCP/UDP: Closing socket Tue Oct 26 12:33:06 2010 SIGUSR1[soft,tls-error] received, process restarting Tue Oct 26 12:33:06 2010 Restart pause, 5 second(s) Tue Oct 26 12:33:11 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 12:33:11 2010 Re-using SSL/TLS context Tue Oct 26 12:33:11 2010 LZO compression initialized Tue Oct 26 12:33:11 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 12:33:11 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 12:33:11 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 12:33:11 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 12:33:11 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 12:33:11 2010 TCP connection established with 67.228.223.12:3389 Tue Oct 26 12:33:11 2010 TCPv4_CLIENT link local: [undef] Tue Oct 26 12:33:11 2010 TCPv4_CLIENT link remote: 67.228.223.12:3389 Tue Oct 26 12:33:12 2010 TLS: Initial packet from 67.228.223.12:3389, sid=128becf9 f62adf0c Tue Oct 26 12:33:12 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 12:33:12 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 12:33:12 2010 TCP/UDP: Closing socket Tue Oct 26 12:33:12 2010 SIGUSR1[soft,tls-error] received, process restarting Tue Oct 26 12:33:12 2010 Restart pause, 5 second(s) Tue Oct 26 12:33:17 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 12:33:17 2010 Re-using SSL/TLS context Tue Oct 26 12:33:17 2010 LZO compression initialized Tue Oct 26 12:33:17 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 12:33:17 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 12:33:17 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 12:33:17 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 12:33:17 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 12:33:20 2010 TCP/UDP: Closing socket Tue Oct 26 12:33:20 2010 SIGTERM[hard,init_instance] received, process exiting Guys I am extremely sorry for not presenting my error Log properly, please forgive me and give me your valuable advice. I am using windows 7 and I am using openvpn mainly to bypass censorship at UAE. I am using only client config file. Ca.crt file is in config folder Thanks and regards Nitin My error Log with Config1 file Tue Oct 26 21:24:34 2010 OpenVPN 2.0.9 Win32-MinGW [SSL] [LZO] built on Oct 1 2006 Tue Oct 26 21:24:46 2010 IMPORTANT: OpenVPN's default port number is now 1194, based on an official port number assignment by IANA. OpenVPN 2.0-beta16 and earlier used 5000 as the default port. Tue Oct 26 21:24:46 2010 Control Channel Authentication: using 'ta.key' as a OpenVPN static key file Tue Oct 26 21:24:46 2010 Outgoing Control Channel Authentication: Using 160 bit message hash 'SHA1' for HMAC authentication Tue Oct 26 21:24:46 2010 Incoming Control Channel Authentication: Using 160 bit message hash 'SHA1' for HMAC authentication Tue Oct 26 21:24:46 2010 LZO compression initialized Tue Oct 26 21:24:46 2010 Control Channel MTU parms [ L:1544 D:168 EF:68 EB:0 ET:0 EL:0 ] Tue Oct 26 21:24:46 2010 Data Channel MTU parms [ L:1544 D:1450 EF:44 EB:135 ET:0 EL:0 AF:3/1 ] Tue Oct 26 21:24:46 2010 Local Options hash (VER=V4): 'ee93268d' Tue Oct 26 21:24:46 2010 Expected Remote Options hash (VER=V4): 'bd577cd1' Tue Oct 26 21:24:46 2010 Attempting to establish TCP connection with 67.228.223.12:3389 Tue Oct 26 21:24:47 2010 TCP connection established with 67.228.223.12:3389 Tue Oct 26 21:24:47 2010 TCPv4_CLIENT link local: [undef] Tue Oct 26 21:24:47 2010 TCPv4_CLIENT link remote: 67.228.223.12:3389 Tue Oct 26 21:24:47 2010 TLS: Initial packet from 67.228.223.12:3389, sid=4244e662 e5a0572a Tue Oct 26 21:24:47 2010 TLS Error: cannot locate HMAC in incoming packet from 67.228.223.12:3389 Tue Oct 26 21:24:47 2010 Fatal TLS error (check_tls_errors_co), restarting Tue Oct 26 21:24:47 2010 TCP/UDP: Closing socket Tue Oct 26 21:24:47 2010 SIGUSR1[soft,tls-error] received, process restarting client config file: client dev tun proto tcp remote openvpn1.flashvpn.com 3389 float resolv-retry infinite nobind persist-key persist-tun ca ca.crt ns-cert-type server tls-auth ta.key 1 comp-lzo verb 3 mute 20 auth-user-pass route-method exe route-delay 2

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  • .htaccess not working (mod_rewrite)

    - by Mike Curry
    Edit: I am pretty sure my .htaccess file is NOT being executed, and the problem is NOT with my rewrite rules. I have not having any luck getting my .htaccess with mod_rewrite working. Basically all I am trying to do is remove 'www' from "http://www.site.com" and "https://www.site.com". If there is anything I am missing (conf files, etc let me know I willl update this) I jsut can't see whats wrong here... I am using a 1&1 VPS III Virtual private server... anyone ever have this issue? I am using Ubuntu 8.04 Server LTS. Here is my .htaccess file (located @ /var/www/site/trunk/html/) Options +FollowSymLinks RewriteEngine on RewriteCond %{HTTP_HOST} ^www\.(.*) [NC] RewriteRule (.*) //%1/$1 [L,R=301] My mod_rewrite is enabled: The auto regenerated sym link is there in mods-available and /usr/lib/apache2/modules/ contains mod_rewrite.so root@s15348441:/etc/apache2/mods-available# more rewrite.load LoadModule rewrite_module /usr/lib/apache2/modules/mod_rewrite.so root@s15348441:/var/log# apache2ctl -t -D DUMP_MODULES Loaded Modules: core_module (static) log_config_module (static) logio_module (static) mpm_prefork_module (static) http_module (static) so_module (static) alias_module (shared) auth_basic_module (shared) authn_file_module (shared) authz_default_module (shared) authz_groupfile_module (shared) authz_host_module (shared) authz_user_module (shared) autoindex_module (shared) cgi_module (shared) dir_module (shared) env_module (shared) mime_module (shared) negotiation_module (shared) php5_module (shared) rewrite_module (shared) setenvif_module (shared) ssl_module (shared) status_module (shared) Syntax OK My apache config files: apache2.conf # # Based upon the NCSA server configuration files originally by Rob McCool. # # This is the main Apache server configuration file. It contains the # configuration directives that give the server its instructions. # See http://httpd.apache.org/docs/2.2/ for detailed information about # the directives. # # Do NOT simply read the instructions in here without understanding # what they do. They're here only as hints or reminders. If you are unsure # consult the online docs. You have been warned. # # The configuration directives are grouped into three basic sections: # 1. Directives that control the operation of the Apache server process as a # whole (the 'global environment'). # 2. Directives that define the parameters of the 'main' or 'default' server, # which responds to requests that aren't handled by a virtual host. # These directives also provide default values for the settings # of all virtual hosts. # 3. Settings for virtual hosts, which allow Web requests to be sent to # different IP addresses or hostnames and have them handled by the # same Apache server process. # # Configuration and logfile names: If the filenames you specify for many # of the server's control files begin with "/" (or "drive:/" for Win32), the # server will use that explicit path. If the filenames do *not* begin # with "/", the value of ServerRoot is prepended -- so "/var/log/apache2/foo.log" # with ServerRoot set to "" will be interpreted by the # server as "//var/log/apache2/foo.log". # ### Section 1: Global Environment # # The directives in this section affect the overall operation of Apache, # such as the number of concurrent requests it can handle or where it # can find its configuration files. # # # ServerRoot: The top of the directory tree under which the server's # configuration, error, and log files are kept. # # NOTE! If you intend to place this on an NFS (or otherwise network) # mounted filesystem then please read the LockFile documentation (available # at <URL:http://httpd.apache.org/docs-2.1/mod/mpm_common.html#lockfile>); # you will save yourself a lot of trouble. # # Do NOT add a slash at the end of the directory path. # ServerRoot "/etc/apache2" # # The accept serialization lock file MUST BE STORED ON A LOCAL DISK. # #<IfModule !mpm_winnt.c> #<IfModule !mpm_netware.c> LockFile /var/lock/apache2/accept.lock #</IfModule> #</IfModule> # # PidFile: The file in which the server should record its process # identification number when it starts. # This needs to be set in /etc/apache2/envvars # PidFile ${APACHE_PID_FILE} # # Timeout: The number of seconds before receives and sends time out. # Timeout 300 # # KeepAlive: Whether or not to allow persistent connections (more than # one request per connection). Set to "Off" to deactivate. # KeepAlive On # # MaxKeepAliveRequests: The maximum number of requests to allow # during a persistent connection. Set to 0 to allow an unlimited amount. # We recommend you leave this number high, for maximum performance. # MaxKeepAliveRequests 100 # # KeepAliveTimeout: Number of seconds to wait for the next request from the # same client on the same connection. # KeepAliveTimeout 15 ## ## Server-Pool Size Regulation (MPM specific) ## # prefork MPM # StartServers: number of server processes to start # MinSpareServers: minimum number of server processes which are kept spare # MaxSpareServers: maximum number of server processes which are kept spare # MaxClients: maximum number of server processes allowed to start # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_prefork_module> StartServers 5 MinSpareServers 5 MaxSpareServers 10 MaxClients 150 MaxRequestsPerChild 0 </IfModule> # worker MPM # StartServers: initial number of server processes to start # MaxClients: maximum number of simultaneous client connections # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadsPerChild: constant number of worker threads in each server process # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_worker_module> StartServers 2 MaxClients 150 MinSpareThreads 25 MaxSpareThreads 75 ThreadsPerChild 25 MaxRequestsPerChild 0 </IfModule> # These need to be set in /etc/apache2/envvars User ${APACHE_RUN_USER} Group ${APACHE_RUN_GROUP} # # AccessFileName: The name of the file to look for in each directory # for additional configuration directives. See also the AllowOverride # directive. # AccessFileName .htaccess # # The following lines prevent .htaccess and .htpasswd files from being # viewed by Web clients. # <Files ~ "^\.ht"> Order allow,deny Deny from all </Files> # # DefaultType is the default MIME type the server will use for a document # if it cannot otherwise determine one, such as from filename extensions. # If your server contains mostly text or HTML documents, "text/plain" is # a good value. If most of your content is binary, such as applications # or images, you may want to use "application/octet-stream" instead to # keep browsers from trying to display binary files as though they are # text. # DefaultType text/plain # # HostnameLookups: Log the names of clients or just their IP addresses # e.g., www.apache.org (on) or 204.62.129.132 (off). # The default is off because it'd be overall better for the net if people # had to knowingly turn this feature on, since enabling it means that # each client request will result in AT LEAST one lookup request to the # nameserver. # HostnameLookups Off # ErrorLog: The location of the error log file. # If you do not specify an ErrorLog directive within a <VirtualHost> # container, error messages relating to that virtual host will be # logged here. If you *do* define an error logfile for a <VirtualHost> # container, that host's errors will be logged there and not here. # ErrorLog /var/log/apache2/error.log # # LogLevel: Control the number of messages logged to the error_log. # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. # LogLevel warn # Include module configuration: Include /etc/apache2/mods-enabled/*.load Include /etc/apache2/mods-enabled/*.conf # Include all the user configurations: Include /etc/apache2/httpd.conf # Include ports listing Include /etc/apache2/ports.conf # # The following directives define some format nicknames for use with # a CustomLog directive (see below). # If you are behind a reverse proxy, you might want to change %h into %{X-Forwarded-For}i # LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %b" common LogFormat "%{Referer}i -> %U" referer LogFormat "%{User-agent}i" agent # # ServerTokens # This directive configures what you return as the Server HTTP response # Header. The default is 'Full' which sends information about the OS-Type # and compiled in modules. # Set to one of: Full | OS | Minor | Minimal | Major | Prod # where Full conveys the most information, and Prod the least. # ServerTokens Full # # Optionally add a line containing the server version and virtual host # name to server-generated pages (internal error documents, FTP directory # listings, mod_status and mod_info output etc., but not CGI generated # documents or custom error documents). # Set to "EMail" to also include a mailto: link to the ServerAdmin. # Set to one of: On | Off | EMail # ServerSignature On # # Customizable error responses come in three flavors: # 1) plain text 2) local redirects 3) external redirects # # Some examples: #ErrorDocument 500 "The server made a boo boo." #ErrorDocument 404 /missing.html #ErrorDocument 404 "/cgi-bin/missing_handler.pl" #ErrorDocument 402 http://www.example.com/subscription_info.html # # # Putting this all together, we can internationalize error responses. # # We use Alias to redirect any /error/HTTP_<error>.html.var response to # our collection of by-error message multi-language collections. We use # includes to substitute the appropriate text. # # You can modify the messages' appearance without changing any of the # default HTTP_<error>.html.var files by adding the line: # # Alias /error/include/ "/your/include/path/" # # which allows you to create your own set of files by starting with the # /usr/share/apache2/error/include/ files and copying them to /your/include/path/, # even on a per-VirtualHost basis. The default include files will display # your Apache version number and your ServerAdmin email address regardless # of the setting of ServerSignature. # # The internationalized error documents require mod_alias, mod_include # and mod_negotiation. To activate them, uncomment the following 30 lines. # Alias /error/ "/usr/share/apache2/error/" # # <Directory "/usr/share/apache2/error"> # AllowOverride None # Options IncludesNoExec # AddOutputFilter Includes html # AddHandler type-map var # Order allow,deny # Allow from all # LanguagePriority en cs de es fr it nl sv pt-br ro # ForceLanguagePriority Prefer Fallback # </Directory> # # ErrorDocument 400 /error/HTTP_BAD_REQUEST.html.var # ErrorDocument 401 /error/HTTP_UNAUTHORIZED.html.var # ErrorDocument 403 /error/HTTP_FORBIDDEN.html.var # ErrorDocument 404 /error/HTTP_NOT_FOUND.html.var # ErrorDocument 405 /error/HTTP_METHOD_NOT_ALLOWED.html.var # ErrorDocument 408 /error/HTTP_REQUEST_TIME_OUT.html.var # ErrorDocument 410 /error/HTTP_GONE.html.var # ErrorDocument 411 /error/HTTP_LENGTH_REQUIRED.html.var # ErrorDocument 412 /error/HTTP_PRECONDITION_FAILED.html.var # ErrorDocument 413 /error/HTTP_REQUEST_ENTITY_TOO_LARGE.html.var # ErrorDocument 414 /error/HTTP_REQUEST_URI_TOO_LARGE.html.var # ErrorDocument 415 /error/HTTP_UNSUPPORTED_MEDIA_TYPE.html.var # ErrorDocument 500 /error/HTTP_INTERNAL_SERVER_ERROR.html.var # ErrorDocument 501 /error/HTTP_NOT_IMPLEMENTED.html.var # ErrorDocument 502 /error/HTTP_BAD_GATEWAY.html.var # ErrorDocument 503 /error/HTTP_SERVICE_UNAVAILABLE.html.var # ErrorDocument 506 /error/HTTP_VARIANT_ALSO_VARIES.html.var # Include of directories ignores editors' and dpkg's backup files, # see README.Debian for details. # Include generic snippets of statements Include /etc/apache2/conf.d/ # Include the virtual host configurations: Include /etc/apache2/sites-enabled/ My default config file for www on apache NameVirtualHost *:80 <VirtualHost *:80> ServerAdmin [email protected] #SSLEnable #SSLVerifyClient none #SSLCertificateFile /usr/local/ssl/crt/public.crt #SSLCertificateKeyFile /usr/local/ssl/private/private.key DocumentRoot /var/www/site/trunk/html <Directory /> Options FollowSymLinks AllowOverride all </Directory> <Directory /var/www/site/trunk/html> Options Indexes FollowSymLinks MultiViews AllowOverride all Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog /var/log/apache2/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog /var/log/apache2/access.log combined ServerSignature On Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> </VirtualHost> My ssl config file NameVirtualHost *:443 <VirtualHost *:443> ServerAdmin [email protected] #SSLEnable #SSLVerifyClient none #SSLCertificateFile /usr/local/ssl/crt/public.crt #SSLCertificateKeyFile /usr/local/ssl/private/private.key DocumentRoot /var/www/site/trunk/html <Directory /> Options FollowSymLinks AllowOverride all </Directory> <Directory /var/www/site/trunk/html> Options Indexes FollowSymLinks MultiViews AllowOverride all Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog /var/log/apache2/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn SSLEngine On SSLCertificateFile /usr/local/ssl/crt/public.crt SSLCertificateKeyFile /usr/local/ssl/private/private.key CustomLog /var/log/apache2/access.log combined ServerSignature On Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> </VirtualHost> My /etc/apache2/httpd.conf is blank The directory /etc/apache2/conf.d has nothing in it but one file (charset) contents of /etc/apache2/conf.dcharset # Read the documentation before enabling AddDefaultCharset. # In general, it is only a good idea if you know that all your files # have this encoding. It will override any encoding given in the files # in meta http-equiv or xml encoding tags. #AddDefaultCharset UTF-8 My apache error.log [Wed Jun 03 00:12:31 2009] [error] [client 216.168.43.234] client sent HTTP/1.1 request without hostname (see RFC2616 section 14.23): /w00tw00t.at.ISC.SANS.DFind:) [Wed Jun 03 05:03:51 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:03:54 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:13:48 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:13:51 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:13:54 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:13:57 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:17:28 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 05:26:23 2009] [notice] caught SIGWINCH, shutting down gracefully [Wed Jun 03 05:26:34 2009] [notice] Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch mod_ssl/2.2.8 OpenSSL/0.9.8g configured -- resuming normal operations [Wed Jun 03 06:03:41 2009] [notice] caught SIGWINCH, shutting down gracefully [Wed Jun 03 06:03:51 2009] [notice] Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch mod_ssl/2.2.8 OpenSSL/0.9.8g configured -- resuming normal operations [Wed Jun 03 06:25:07 2009] [notice] caught SIGWINCH, shutting down gracefully [Wed Jun 03 06:25:17 2009] [notice] Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch mod_ssl/2.2.8 OpenSSL/0.9.8g configured -- resuming normal operations [Wed Jun 03 12:09:25 2009] [error] [client 61.139.105.163] File does not exist: /var/www/site/trunk/html/fastenv [Wed Jun 03 15:04:42 2009] [notice] Graceful restart requested, doing restart [Wed Jun 03 15:04:43 2009] [notice] Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch mod_ssl/2.2.8 OpenSSL/0.9.8g configured -- resuming normal operations [Wed Jun 03 15:29:51 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 15:29:54 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 15:30:32 2009] [error] [client 99.247.237.46] File does not exist: /var/www/site/trunk/html/favicon.ico [Wed Jun 03 15:45:54 2009] [notice] caught SIGWINCH, shutting down gracefully [Wed Jun 03 15:46:05 2009] [notice] Apache/2.2.8 (Ubuntu) PHP/5.2.4-2ubuntu5.6 with Suhosin-Patch mod_ssl/2.2.8 OpenSSL/0.9.8g configured -- resuming normal operations

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  • log in and send sms with java

    - by noobed
    I'm trying to log into a site and afterwards to send a SMS (you can do that for free by the site - it's nothing more than just enter some text into some fields and 'submit'). I've used wireshark to track some of the post/get requests that my machine has been exchanging with the server - when using the browser. I'd like to paste some of my Java code: URL url; String urlP = "maccount=myRawUserName7&" + "mpassword=myRawPassword&" + "redirect_http=http&" + "submit=........"; String urlParameters = URLEncoder.encode(urlP, "CP1251"); HttpURLConnection connection = null; // Create connection url = new URL("http://www.mtel.bg/1/mm/smscenter/mc/sendsms/ma/index/mo/1"); connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("POST"); //I'm not really sure if these RequestProperties are necessary //so I'll leave them as a comment // connection.setRequestProperty("Content-Type", // "application/x-www-form-urlencoded"); // connection.setRequestProperty("Accept-Charset", "CP1251"); // connection.setRequestProperty("Content-Length", // "" + Integer.toString(urlParameters.getBytes().length)); // connection.setRequestProperty("Content-Language", "en-US"); connection.setUseCaches(false); connection.setDoInput(true); connection.setDoOutput(true); // Send request DataOutputStream wr = new DataOutputStream( connection.getOutputStream()); wr.writeBytes(urlParameters); wr.flush(); wr.close(); String headerName[] = new String[10]; int count = 0; for (int i = 1; (headerName[count] = connection.getHeaderFieldKey(i)) != null; i++) { if (headerName[count].equals("Set-Cookie")) { headerName[count++] = connection.getHeaderField(i); } } //I'm not sure if I have to close the connection here or not if (connection != null) { connection.disconnect(); } //the code above should be the login part //----------------------------------------- //this is copy-pasted from wireshark's info. String smsParam="from=men&" + "sender=0&" + "msisdn=359886737498&" + "tophone=0&" + "smstext=tova+e+proba%21+1.&" + "id=&" + "sendaction=&" + "direction=&" + "msgLen=84"; url = new URL("http://www.mtel.bg/moyat-profil-sms-tsentar_3004/" + "mm/smscenter/mc/sendsms/ma/index"); connection = (HttpURLConnection) url.openConnection(); connection.setRequestMethod("POST"); connection.setRequestProperty("Cookie", headerName[0]); connection.setRequestProperty("Cookie", headerName[1]); //conn urlParameters = URLEncoder.encode(urlP, "CP1251"); connection.setUseCaches(false); connection.setDoInput(true); connection.setDoOutput(true); wr = new DataOutputStream( connection.getOutputStream()); wr.writeBytes(urlParameters); wr.flush(); wr.close(); //I'm not rly sure what exactly to do with this response. // Get Response InputStream is = connection.getInputStream(); BufferedReader rd = new BufferedReader(new InputStreamReader(is, "CP1251")); String line; StringBuffer response = new StringBuffer(); while ((line = rd.readLine()) != null) { response.append(line); response.append('\r'); } rd.close(); System.out.println(response.toString()); if (connection != null) { connection.disconnect(); } so that's my code so far. When I execute it ... I don't receive any text on my phone - so it clearly doesn't work as supposed to. I would appreciate any guidance or remarks. Is my cookie handling wrong? Is my login method wrong? Do I pass the right URLs. Do I encode and send the parameter string correctly? Is there any addition valuable data from these POSTs I should take? P.S. just in any case let me tell you that the username and password is not real. For security reasons I don't want to give valid ones. (I think this is appropriate approach) Here are the POST requests: POST /1/mm/auth/mc/auth/ma/index/mo/1 HTTP/1.1 Host: www.mtel.bg User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20100101 Firefox/15.0.1 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip, deflate Connection: keep-alive Referer: http://www.mtel.bg/1/mm/smscenter/mc/sendsms/ma/index/mo/1 Cookie: __utma=209782857.541729286.1349267381.1349270269.1349274374.3; __utmc=209782857; __utmz=209782857.1349267381.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); __atuvc=28%7C40; PHPSESSID=q0mage2usmv34slcv3dmd6t057; __utmb=209782857.3.10.1349274374 Content-Type: multipart/form-data; boundary=---------------------------151901450223722 Content-Length: 475 -----------------------------151901450223722 Content-Disposition: form-data; name="maccount" myRawUserName -----------------------------151901450223722 Content-Disposition: form-data; name="mpassword" myRawPassword -----------------------------151901450223722 Content-Disposition: form-data; name="redirect_https" http -----------------------------151901450223722 Content-Disposition: form-data; name="submit" ........ -----------------------------151901450223722-- HTTP/1.1 302 Found Server: nginx Date: Wed, 03 Oct 2012 14:26:40 GMT Content-Type: text/html; charset=Utf-8 Connection: close Expires: Thu, 19 Nov 1981 08:52:00 GMT Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache Location: /moyat-profil-sms-tsentar_3004/mm/smscenter/mc/sendsms/ma/index Content-Length: 0 The above text is vied with wireshark's follow tcp stream when pressing the log in button. POST /moyat-profil-sms-tsentar_3004/mm/smscenter/mc/sendsms/ma/index HTTP/1.1 *same as the above ones* Referer: http://www.mtel.bg/moyat-profil-sms-tsentar_3004/mm/smscenter/mc/sendsms/ma/index Cookie: __utma=209782857.541729286.1349267381.1349270269.1349274374.3; __utmc=209782857; __utmz=209782857.1349267381.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); __atuvc=29%7C40; PHPSESSID=q0mage2usmv34slcv3dmd6t057; __utmb=209782857.4.10.1349274374 Content-Type: application/x-www-form-urlencoded Content-Length: 147 from=men&sender=0&msisdn=35988888888&tophone=0&smstext=this+is+some+FREE+SMS+text%21+100+char+per+sms+only%21&id=&sendaction=&direction=&msgLen=50 HTTP/1.1 302 Found Server: nginx Date: Wed, 03 Oct 2012 14:31:38 GMT Content-Type: text/html; charset=Utf-8 Connection: close Expires: Thu, 19 Nov 1981 08:52:00 GMT Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0 Pragma: no-cache Location: /moyat-profil-sms-tsentar_3004/mm/smscenter/mc/sendsms/ma/success/s/1 Content-Length: 0 The above text is when you press the send button.

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  • SOA PARTNER COMMUNITY NEWSLETTER JULY 2012

    - by mseika
    SOA PARTNER COMMUNITY NEWSLETTER JULY 2012 Dear SOA partner community member To provide our community members the best of our knowledge, we want your feedback on our SOA Partner community. Thus we are organizing SOA Partner Community Survey 2012. We request you to participate in the survey and give your valuable feedback on various areas of marketing, sales and education. To continue our successful BPM Suite, Oracle is launching together with you Process Accelerators initiative. It’s your opportunity to co-develop and market predefined processes. Oracle Fusion Applications Design Patterns are a great tool to develop your SOA or BPM solution or process accelerators. To promote your SOA & BPM Specialization we continue to offer several benefits. This month we would like to highlight our Specialization Plaques - make sure you request one for your office! Our Fusion Middleware Summer Camps are booked out, if could not get a seat you can attend the SOA & BPM track @ Virtual Developer Day: Oracle Fusion Development Oracle demo systems offer´s two new demos: Business Driven Development based on BPM Suite & SOA Lifecycle Management. Jürgen KressOracle SOA & BPM Partner Adoption EMEA NEW CONTENT Community SurveyProcess Accelerators KitPlaques SOA & BPM SpecializedSOA & BPM at Virtual Developer Day News from our Partners & CommunityOverview of SOA Diagnostics in 11.1.1.6 Business driven development(BDD) demo now available! SOA Lifecycle Management Oracle Fusion applications design patterns Updated material by Oracle Connect and Network SOA Blogs SOA on Facebook SOA on LinkedIn SOA on Twitter Mix SOA Forum COMMUNITY SURVEY Like every year we would like to get your feedback in our SOA Partner Community Survey 2012. Make sure that You attend to further develop our community and support our planning! It is key for us to get your feedback to prepare for the next fiscal year. Back to top PROCESS ACCELERATORS KIT Oracle is very interested to co-develop and market with you, our partners, pre-defined processes for BPM Suite.I am very happy to announce a new program called “Oracle BPM Partner Solution Catalog”. This program will provide a one-stop shop for our customers looking for Oracle BPM partner solutions available in the market today.The Oracle BPM Solution Catalog will be hosted on our very popular Oracle Technology Network (OTN). To give you an idea of the scale of customer visibility, OTN today receives over 1Million hits per day from our business and developer community. We would like to invite you to list your Oracle BPM 11g solutions available today.In order to participate in this program, you need to do the following: Fill in the attached slide templates - #3 and #4 for each Oracle BPM 11g solution you would like to list on OTN.Please add links to whitepapers , videos, references to the specific solution in the template slide. We recommend that you create a landing page on your website for these linked artifacts and just point to the same from within the PowerPoint template. This will give you the flexibility to update the information as frequently as needed. If you have the particular solution in production or a reference available, please list them as well. Send the PowerPoint template slides (1 set of slides for each Oracle BPM solution) to [email protected]. In addition to having the opportunity to list your solutions on OTN for Oracle customers, you will have the chance to advertise your new wins/implementations/solutions in an Oracle Sponsored PM Webinar held every quarter. This program is targeted to go live by the end of summer 2012. At this point, we are targeting a soft launch in July end 2012 so send on your BPM solutions information as soon as possible. We would love to have your solution(s) listed in the “Oracle BPM Partner Solution Catalog” at the time of the launch. This will be a live repository so you can keep adding more solutions as they become available. If you have any questions, please feel free to contact us [email protected], Product Strategy Director, Oracle BPM , Phone +1 650.506.5486.Thank you and look forward to hearing from you. Oracle BPM team Process Accelerators Overview.pdf ProcessAcceleratorsDataSheet.pdf Demos draUPK.zip & trmUPK.zip BPM Solution repository slides.ppt Additional BPM material BPM Process Development Lifecycle Document that describes recommended approach to collaborative process modeling across business and IT tools ADF 11g PS5 Application with Customized BPM Worklist Task Flow (MDS Seeded Customization) by Andrejus Baranovskis BPMN process editor problems in 11.1.1.6 by Mark Nelson BPM – Disable DBMS job to refresh B2B Materialized View by Mark Nelson For the complete kit please visit the BPM folder at our SOA Community Workspace (SOA Community membership required). For the complete presentation please visit our SOA Community Workspace (SOA Community membership required). Information is Oracle and Partner confidential! Back to top PLAQUES SOA & BPM SPECIALIZED We continue to offer you a nice SOA & BPM Specialization plaque with your logo to proof your success. If you are a SOA or BPM Specialized partner and would like to request the plaque please send Brigitte an e-mail with the following information: Partner Name Partner logo (preferred eps file) Partner Status gold or platinum Your shipping address Your Specialization: SOA or BPM We recommend to mount the plaque at your office reception in addition you can use the SOA Specialization logos at your website download Logo: Gold & Platinum or the BPM logos Gold & Platinum Back to top SOA & BPM AT VIRTUAL DEVELOPER DAY Register now for this FREE hands-on online workshop Get up to date and learn everything you wanted to know about Oracle ADF & Fusion Development plus live Q&A chats with Oracle technical staffOracle Application Development Framework (ADF) is the standards based, strategic framework for Oracle Fusion Applications and Oracle Fusion Middleware. Oracle ADF’s integration with the Oracle SOA Suite, Oracle WebCenter and Oracle BI creates a complete productive development platform for your custom applications.Join us at this FREE virtual event and learn the latest in Fusion Development including: Is Oracle ADF development faster and simpler than Forms, Apex or .Net? Mobile Application Development with ADF Mobile Oracle ADF development with Eclipse Oracle WebCenter Portal and ADF Development Application Lifecycle Management with ADF Building Process Centric Applications with ADF and BPM Oracle Business Intelligence and ADF Integration Live Q&A chats with Oracle technical staff Developer lead, manager or architect - this event has something for everyone. Don’t miss this opportunity.Tuesday, July 10, 2012. 9:00 a.m. PT -1:00 p.m. PT 11:00 a.m. CT - 3:00 p.m. CT 12:00 p.m. ET - 4:00 p.m. ET 1:00 p.m. BRT - 5:00 p.m. BRT Register online now! for this FREE event. Agenda: 09:00 am Opening 09:30 am Keynote: Oracle Fusion Development Track1Introduction to Fusion Development Track2What's New in Fusion Development Track3Fusion Development in the Enterprise 10:00 am Is Oracle ADF Development Faster and Simpler than Oracle Forms, APEX or .Net? Mobile Application Development with ADF Mobile Oracle WebCenter Portal and ADF Development 11:00 am Rich Web UI made simple - an ADF Faces Overview Oracle Enterprise Pack for Eclipse - ADF Development Building Process Centric Applications with ADF and BPM 12:00 noon Next Generation Controller for JSF Application Lifecycle Management for ADF Oracle Business Intelligence and ADF Integration *Hands On Lab – WebCenter and ADF Lab w/ JDeveloper - Lab materials will be provided ahead of the event to give you ample time to work through the lab and increase the productivity of the live chat sessions the day of the event. Sessions abstractsRegister online now! for this FREE event Read more on Community Events and post your comment here. Back to top NEWS FROM OUR PARTNERS AND COMMUNITY Send your tweets @soacommunity #soacommunity and follow us at http://twitter.com/soacommunity JDeveloper & ADF?Troubleshooting BPMN process editor problems in 11.1.1.6http://dlvr.it/1p0FfS SOA Community?SOA & BPM @ Virtual Developer Day: Oracle Fusion Development - July 10th 2012https://soacommunity.wordpress.com/2012/07/02/soa-bpm-virtual-developer-day- oracle-fusion-developmentjuly-10th-2012/#soacommunity #soa #bom #education orclateamsoa ?A-Team Blog #ateam: BAM design pointers - In working recently with a large Oracle customer on SOA and BAM, I discove.http://ow.ly/1kYqES SOA CommunitySOA Community Newsletter June 2012http://wp.me/p10C8u-qw SOA CommunityBPMN process editor problems in 11.1.1.6 by Mark Nelsonhttp://redstack.wordpress.com/2012/06/27/ bpmn-process-editor-problems-in-11-1-1-6 #soacommunity #bpm OTNArchBeat ?SOA Learning Library: free short, topic-focused training on Oracle SOA & BPM products | @SOACommunity http://pub.vitrue.com/NE1G Andrejus Baranovskis ?ADF 11g PS5 Application with Customized BPM Worklist Task Flow (MDS Seeded Customization)http://fb.me/1coX4r1X1 SOA CommunitySOA Learning Library provides a comprehensive curriculum for the SOA and BPM product suites https://soacommunity.wordpress.com/2012/06/27/soa-learning-library #soacommunity #soa #bpm OTNArchBeat ?A Universal JMX Client for Weblogic - Part 1: Monitoring BPEL Thread Pools in SOA 11g | Stefan Koserhttp://pub.vitrue.com/mQVZ OTNArchBeat ?BPM - Disable DBMS job to refresh B2B Materialized View | Mark Nelson http://pub.vitrue.com/3PR0Oracle SOA ?Learn how Choice Hotels Implements Innovative Google Maps Solution with #OracleSOA http://bit.ly/MTwIJ3 SOA Communitytop Tweets SOA Partner Community - June 2012 Send your tweets @soacommunity #soacommunity https://soacommunity.wordpress.com/2012/06/25/top-tweets-soa-partner-community-june-2012 Torsten Winterberg#OPITZ is pushing Oracle commitment to the next level: New Specializations done: ADF, BPM, WLS, Exadatahttp://bit.ly/KX1WVS ServiceTechSymposium ?Only 8 more days left until Super Early Bird Registration Discount expires! http://www.servicetechsymposium.com OracleBlogsSOA Management in 3 minutes - Video explainerhttp://ow.ly/1kN5pn SOA Community ?SOA, Cloud & Service Technology Symposium 2012 London - Enter Promo Code: Djmxz370https://soacommunity.wordpress.com/2012/06/22/soa-cloud-service-technology-symposium-2012-london #soasymposium #soacommunity #soa Heidi BuelowGreat course! w David Read RT @soacommunity: product management ADF for BPM training 5 seats left https://soacommunity.wordpress.com/2012/06/12/fusion-middleware-summer-campsadvanced-partner-trainings/ #bpm #soacommunity SOA Community ?product management ADF for BPM training 5 seats lefthttps://soacommunity.wordpress.com/2012/06/12/fusion-middleware-summer-campsadvanced-partner-trainings/ #bpm #soacommunity OTNArchBeat ?Oacle Fusion Applications Design Patterns Now Available For Developers | Ultan O'Broinhttp://pub.vitrue.com/UEiF OTNArchBeat ?SOA, Cloud & Service Technology Symposium 2012London - Special Oracle Discounthttp://pub.vitrue.com/8E0J SOA CommunityBecome a facebook fan of soacommunity http://www.facebook.com/soacommunity #soacommunity SOA Community ?SOA Suite HealthCare Integration Architecture https://blogs.oracle.com/SOAForHealthcare/entry/soa_suite_healthcare_integration_architecture #soacommunity #soa Andrejus Baranovskis ?Running Pre-built Virtual Machine for SOA Suite and BPM Suite 11g PS5 on Mac OS X Snow Leopard (10.6http://fb.me/vB8nO0Vg OracleBlogsPrinciples of Service-Oriented Architecture by Douwe P. van den Bos http://ow.ly/1kIcOP OTNArchBeatOracle Public Cloud Architecture | @TylerJewell http://ow.ly/bHAcL The SOA Network ?Business Process Management, Service-Oriented Architecture, and Web 2.0: Business Transformation or.http://bit.ly/LBgREL #ITNews #SOA OracleBlogs ?Oracle SOA Foundation Practitioner Certificationhttp://ow.ly/1kGYYg Frank Nimphius ?Learn Advanced ADF. ORACLE Fusion Middleware Summer Camps in Lisbon - July 9th - 13thhttp://bit.ly/KGCl3i SOA CommunityTransform Your Application Integration with Best Practices from Oracle Customershttps://blogs.oracle.com/SOA/entry/transform_your_application_integration_with #soacommunity #soa #bpm Simone GeibWhat you always wanted to know about #oraclesoa diagnostics: Shawn Bailey, Overview of SOA Diagnostics in 11.1.1.6,http://ow.ly/bxK0M Oracle SOA ?Save the date: Jun 21 10AM, SOA & BPM Customer Insight Series. Hear how Choice Hotels went from legacy to #oraclesoa http://bit.ly/LsNDGl OTNArchBeat ?New VirtualBox images for Oracle SOA Suite & Oracle BPM Suite 11.1.1.6.0http://ow.ly/bwDAl OracleBlogs ?Process development lifecycle in Oracle BPM 11g http://ow.ly/1ktesY Daniel AmadeiNew post: Oracle BPEL 11g Message Delivery & Recovery.http://amadei.com.br/blog/index.php /oracle-bpel-11g-message-delivery SOA Community ?Sending out the June edition of the #soacommunity newsletter - read it or become a member http://www.oracle.com/goto/emea/soa!#soa #bpm Arun Pareek ?For the past six months Ahmed Aboulnaga and me have been working on Oracle SOA Suite 11g Administrator's Handbook.http://lnkd.in/CAvpUQ SOA CommunitySun shine all day no clouds - solar eclipse is over... #sunshine #cloud http://www.infoq.com/presentations/Swarm-Computing Michel SchildmeijerWatch my blog Oracle Service Bus 11g: listing projects and services with WLST - part 1 http://lnkd.in/B7f3GQ @TITAN_GS @wlscommunity OTNArchBeatBook Review: Oracle Application Integration Architecture (AIA) Foundation Pack 11gR1: Essentials | Rajesh Rahejahttp://ow.ly/bn2cc OTNArchBeat ?Driving from Business Architecture to Business Process Services | @vghariharan http://ow.ly/bn5UB OTNArchBeat ?SOA Analysis within the Department of Defense Architecture Framework (DoDAF) 2.0 - Part II | Dawit Lessanu http://ow.ly/bn6sX Simone Geib ?Contact me directly for ideas how to improvehttp://bit.ly/advancedsoasuite and additional posts, presentations, white papers, ... #soasuite Simone Geib ?#soasuite advanced OTN page has become too cluttered. Broke it into separate pages to start with. http://bit.ly/advancedsoasuite OracleBlogs ?June Webcast: SOA Gateway Implementation and Troubleshooting (2 sessions) http://ow.ly/1kbRFA ServiceTechSymposium ?New session just posted to calendar: "NoSQL for Data Services, Data Virtualization & Big Data" by Guido Schmutz, Trivadis AG ://ow.ly/bjjOeDebra Lilley ?looks good - real proof people are using the apps ! RT @fteter: Very cool Fusion Applications Help site: http://bit.ly/L3nvOR #FusionApps demed ?rapid proliferation of cloud computing will drive convergence of SOA and cloud paradigms" http://ovum.com/2012/05/18/soa-paves-the-way-for-cloud/ SOA CommunityMiddleware Oracle Excellence Awards 2012-HAPPY NEW YEAR! https://soacommunity.wordpress.com/2012/05/31/middleware-oracle-excellence-awards-2012happy-new-year/ #soacommunity #opn #opnaward #specialization #oracle SOA CommunityHappy New Year #soacommunity thanks for the business! Time for a drink http://pic.twitter.com/zkK08KWB OTNArchBeat ?Who should ‘own’ the Enterprise Architecture? | Michael Glas http://bit.ly/K0ge0Q SOA Communitytop Tweets SOA Partner Community &ndash; May 2012 http://wp.me/p10C8u-pP ServiceTechSymposiumNew session just posted to Symposium calendar: "Elastic SOA in the Cloud" by Steve Millidge, C2B2 Consulting http://www.servicetechsymposium.com/agenda2012.php #elastic_soa_in_the_cloud orclateamsoa ?A-Team Blog #ateam: How to Set JVM Parameters in Oracle SOA 11Ghttp://ow.ly/1k2cnl ServiceTechSymposium ?New session just posted to Symposium calendar: "SOA Governance at EDP: A Global Energy Company" by Manuel Rosa, Linkhttp://www.servicetechsymposium.com/agenda2012.php#soa_governance_at_edp SOA Community ?VirtualBox image SOA Suite & BPM Suite 11.1.1.6.0&ndash;Your feedback?http://wp.me/p10C8u-qh Oracle MiddlewareSave the date: Jun 21 10AM, SOA & BPM Customer Insight Series. Hear how Choice Hotels went from legacy to#oraclesoa http://bit.ly/LU1y5N OTNArchBeat ?Goodbye, Silos. Hello SOA. | @stephanieoverbyhttp://pub.vitrue.com/NJJO SOA CommunityBPM Standard Edition - to start your BPM project http://wp.me/p10C8u-qj Please feel free to send us your news! And add your blog to our SOA blog wiki. Back to top OVERVIEW OF SOA DIAGNOSTICS IN 11.1.1.6 What tools are available for diagnosing SOA Suite issues? There are a variety of tools available to help you and Support diagnose SOA Suite issues in 11g but it can be confusing as to which tool is appropriate for a particular situation and what their relationships are. This blog post will introduce the various tools and attempt to clarify what each is for and how they are related. Let's first list the tools we'll be addressing: RDA: Remote Diagnostic Agent DFW: Diagnostic Framework Selective Tracing DMS: Dynamic Monitoring Service ODL: Oracle Diagnostic Logging ADR: Automatic Diagnostics Repository ADRCI: Automatic Diagnostics Repository Command Interpreter WLDF: WebLogic Diagnostic Framework This overview is not mean to be a comprehensive guide on using all of these tools, however, extensive reference materials are included that will provide many more details on their execution. Another point to note is that all of these tools are applicable for Fusion Middleware as a whole but specific products may or may not have implemented features to leverage them. A couple of the tools have a WebLogic Scripting Tool or 'WLST' interface. WLST is a command interface for executing pre-built functions and custom scripts against a domain. A detailed WLST tutorial is beyond the scope of this post but you can find general information here. There are more specific resources in the below sections.In this post when we refer to 'Enterprise Manager' or 'EM' we are referring to Enterprise Manager Fusion Middleware Control. read the full blog post here. Read more on Oracle and post your comment here. Back to top BUSINESS DRIVEN DEVELOPMENT (BDD) DEMO NOW AVAILABLE! For access to the Oracle demo systems please visit OPN and talk to your Partner Expert DSS is pleased to announce the availability of the demo “Business Driven Development“. This innovative demonstration uses a case-study approach to show business users how they can easily streamline their Business Processes - delivering greater efficiency, agility, visibility and collaboration with Oracle BPM and WebCenter. The BDD demonstration uses a case study-based approach to highlight a business problem at a fictional company, Avitek Corporation, and uses Oracle BPM and Oracle WebCenter to solve the business problem. This holistic approach has specifically been used to appeal to a non-technical business analyst user. This demo is NOT focused on product features, but aims to guide users through a complete BPM lifecycle. The scenario is based on improving a simple order process (scenario details are in the demo script). Avitek Corporation is sufferinng from a manual email-driven ordering process. Sales reps don’t know where the customer orders are stuck (no visibility) and finance users are unable to manually approve every order (no automation). There are several areas where this process can be improved with Business Process Management technology. This demo shows how improving following areas will ignificantly help resolve the business problems Avitek Corporation is facing. Areas for improvement include: Utilizing BPM for process management, rather than an unregulated, email-based process. Utilizing automated services, rather than requiring a human to key into a system. For example, Finance checking the customer’s credit rating is something that could be automated. Centralizing business rules that can be integrated into a business process, rather than requiring a human to process them. For example, Finance must determine when orders can be automatically approved. Provide insight and visibility into the process. For example, Sales Rep needs to know the status of their customer’s orders. The BDD Demo uses the following products. Oracle BPM Suite 11g PS4FP Oracle WebCenter 11g PS4FP (for Process Spaces) Oracle Business Activity Monitoring 11g Oracle Database 11g Back to top SOA LIFECYCLE MANAGEMENT For access to the Oracle demo systems please visit OPN and talk to your Partner Expert We are pleased to announce the availability of the SOA Management demo that showcases some of the key provisioning and lifecycle management capabilities of SOA Management Pack Enterprise Edition (EE). This demo specifically focuses on some of the lifecycle management solutions for Oracle SOA Suite and Oracle Service Bus (OSB). Demo Highlights The demo showcases the following capabilities. Provisioning of SOA Composites Provisioning of OSB Projects Provision SOA and OSB artifacts in a future maintenance window Back to top ORACLE FUSION APPLICATIONS DESIGN PATTERNS The Oracle Fusion Applications user experience design patterns are published! These new, reusable usability solutions and best-practices, which will join the Oracle dashboard patterns and guidelines that are already available online, are used by Oracle to artfully bring to life a new standard in the user experience, or UX, of enterprise applications. Now, the Oracle applications development community can benefit from the science behind the Oracle Fusion Applications user experience, too. These Oracle Fusion Applications UX Design Patterns, or blueprints, enable Oracle applications developers and system implementers everywhere to leverage professional usability insight when: tailoring an Oracle Fusion application, creating coexistence solutions that existing users will be delighted with, thus enabling graceful user transitions to Oracle Fusion Applications down the road, or designing exciting, new, highly usable applications in the cloud or on-premise. Based on the Oracle Application Development Framework (ADF) components, the Oracle Fusion Applications patterns and guidelines are proven with real users and in the Applications UX usability labs, so you can get right to work coding productivity-enhancing designs that provide an advantage for your entire business. What’s the best way to get started? We’ve made that easy, too. The Design Filter Tool (DeFT) selects the best pattern for your user type and task. Simply adapt your selection for your own task flow and content, and you’re on your way to a really great applications user experience. More Oracle applications design patterns and training are coming your way in the future. To provide feedback on the sets that are currently available, let me know in the comments! Read more on Fusionapps and post your comment here. Back to top UPDATED ORACLE MATERIAL Integrated SOA Gateway Documentation - Implementation Guide | Developer’s Guide Webcast Series: Oracle’s SOA and Oracle Business Process Management Solutions (Choice Hotels, Eaton, Farmers Insurance) BAM design pointers By Kavitha Srinivasan Seeking Oracle Fusion Middleware Go Live StoriesOracle Fusion Middleware product management is looking for recent go live stories to share with the Oracle sales team, sales consulting, product management and other internal groups. Customer contact details may remain anonymous. Your successful implementation will be featured in a quarterly report. The chance to present on an internal webcast is also available. Contact Maria Forney ([email protected]) if you have a noteworthy implementation success story. This is a good opportunity for partners interested in showcasing Oracle Fusion Middleware implementations, and gaining more exposure within Oracle. Performance tuning resources. All in one: docs, blogs, WPs, ppts: http://bit.ly/soa_resources Back to top HAVE YOU MISSED OUR LAST SOA PARTNER COMMUNITY WEBCASTS? UPK Webcast Business Driven Application Management & BPM11g & Application Grid & GoldenGate & Fusion Middleware Pricing & OC4J to WebLogic & Next Generation SOA & Fusion Middleware in Utility & Fusion Middleware in Communications & Fusion Middleware in Public Services & Fusion Middleware in Financial Services Please check your local OPN trainings calendar for additional training dates and locations. Back to top SOA PARTNER COMMUNITY CALENDAR On-Demand Trainings Event Name Language Type SOA Virtual Developers Day English Tech In-Class Trainings Date Event name Location / Country Contact person Type 09-13.07.2012 BPM Suite 11g advanced training by David Read Lisbon, Portugal Jürgen Kress Tech 09-13.07.2012 ADF 11g advanced training by Grant Ronald and Frank Nimphius Lisbon, Portugal Jürgen Kress Tech 09-13.07.2012 WebCenter Portal advanced training by Stefan Krantz and Angelo Santagata Lisbon, Portugal Jürgen Kress Tech 10.07.2012 Fusion Middleware Virtual Developer Day Online OTN Tech 10- 12.07.2012 WebLogic 12c training by Cosmin Tudor Lisbon, Portugal Jürgen Kress Tech 16-18.07.2012 SOA Suite 11g advanced training by Niall Commiskey Munich, Germany Jürgen Kress Tech 16-18.07.2012 ADF for BPM Suite 11g advanced training by David Read Munich, Germany Jürgen Kress Tech 16-18.07.2012 WebCenter Sites 11g advanced training by Product Management Munich, Germany Jürgen Kress Tech 17-20.07.2012 Oracle BPM 11g Implementation Bootcamp Live Virtual Class Oracle University Tech 23-26.07.2012 Oracle BPM 11g Implementation Bootcamp Utrecht, Netherlands Oracle University Tech 29-31.08.2012 Oracle BPM 11g Implementation Bootcamp Live Virtual Class Oracle University Tech 02-05.10.2012 Oracle BPM 11g Implementation Bootcamp Utrecht, Netherlands Oracle University Tech 15-18.10.2012 Oracle BPM 11g Implementation Bootcamp Utrecht, Netherlands Oracle University Tech 28-30.11.2012 Oracle AIA 11g Implementation Bootcamp Live Virtual Class Oracle University Tech 11-14.12.2012 Oracle BPM 11g Implementation Bootcamp Live Virtual Class Oracle University Tech 20-22.2.2013 Oracle AIA 11g Implementation Bootcamp Utrecht, Netherlands Oracle University Tech 14-17.1.2013 Oracle BPM 11g Implementation Bootcamp Utrecht, Netherlands Oracle University Tech 15-18.3.2013 Oracle BPM 11g Implementation Bootcamp Utrecht, Netherlands Oracle University Tech Please check your local OPN Training Calendar for additional training and locations here. Back to top SOASCHOOL.COM - SOA CERTIFIED PROFESSIONAL(SOACP) PROGRAM The SOASchool.com - SOA Certified Professional (SOACP) program is dedicated to excellence in the field of SOA and service-oriented computing. Through a series of seasoned course modules and exams, IT professionals have the opportunity to obtain a number of different certifications to recognize their accomplishment of gaining "project ready" SOA proficiency. This comprehensive and strictly vendor-neutral program was developed in cooperation with best-selling SOA author Thomas Erl and several major SOA organizations and academic institutions. Through the involvement of the SOA Education Committee, course contents and certification requirements are constantly reviewed and revised to stay current with developments in the service-oriented computing industry. The program is currently comprised of 12 course modules and 5 certifications and is expanding to 18 course modules and 8 certifications throughout 2009. For more information, visit www.soaschool.com and www.soacp.com. Blog Twitter LinkedIn Mix Forum Wiki Back to top YOUR CONTENT ON THE NEWSLETTER AND ON THE SOA COMMUNITY PORTAL Publishing Your StoriesWe would like to invite our partners to publish information in the newsletter or on our SOA Community portal. Especially we are looking for your real life experience with our SOA technology. Please send your documents to Jürgen Kress. We look forward to getting your suggestions! Back to top SOA DISCUSSION FORUM BECOMES INTERACTIVE AT THE SOA COMMUNITY! Do you want to chat to experts, including partners and Oracle SOA Product Development? Do you want to get the latest information about our SOA solutions and events?Attend our private online SOA Discussion Forum at OTN. Please send your OTN forums user name to Brigitte Felisaz. You must be a registered user to access the SOA Discussion Forum. Back to top INVITE YOUR COLLEAGUES TO JOIN THE SOA COMMUNITY Please feel free to invite your colleagues to join the SOA Community and to participate in the SOA Assessment tests. For registration please login the Oracle PartnerNetwork and go to: www.oracle.com/goto/emea/soa For any questions on the above or concerning SOA and Oracle in general please contact the Oracle EMEA Alliances & Channels SOA Team. Best regardsOracle EMEA SOA TeamJürgen Kress Jürgen KressSOA Partner Adoption EMEATel. +49 89 1430 1479E-Mail: [email protected]

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  • Red Gate Coder interviews: Alex Davies

    - by Michael Williamson
    Alex Davies has been a software engineer at Red Gate since graduating from university, and is currently busy working on .NET Demon. We talked about tackling parallel programming with his actors framework, a scientific approach to debugging, and how JavaScript is going to affect the programming languages we use in years to come. So, if we start at the start, how did you get started in programming? When I was seven or eight, I was given a BBC Micro for Christmas. I had asked for a Game Boy, but my dad thought it would be better to give me a proper computer. For a year or so, I only played games on it, but then I found the user guide for writing programs in it. I gradually started doing more stuff on it and found it fun. I liked creating. As I went into senior school I continued to write stuff on there, trying to write games that weren’t very good. I got a real computer when I was fourteen and found ways to write BASIC on it. Visual Basic to start with, and then something more interesting than that. How did you learn to program? Was there someone helping you out? Absolutely not! I learnt out of a book, or by experimenting. I remember the first time I found a loop, I was like “Oh my God! I don’t have to write out the same line over and over and over again any more. It’s amazing!” When did you think this might be something that you actually wanted to do as a career? For a long time, I thought it wasn’t something that you would do as a career, because it was too much fun to be a career. I thought I’d do chemistry at university and some kind of career based on chemical engineering. And then I went to a careers fair at school when I was seventeen or eighteen, and it just didn’t interest me whatsoever. I thought “I could be a programmer, and there’s loads of money there, and I’m good at it, and it’s fun”, but also that I shouldn’t spoil my hobby. Now I don’t really program in my spare time any more, which is a bit of a shame, but I program all the rest of the time, so I can live with it. Do you think you learnt much about programming at university? Yes, definitely! I went into university knowing how to make computers do anything I wanted them to do. However, I didn’t have the language to talk about algorithms, so the algorithms course in my first year was massively important. Learning other language paradigms like functional programming was really good for breadth of understanding. Functional programming influences normal programming through design rather than actually using it all the time. I draw inspiration from it to write imperative programs which I think is actually becoming really fashionable now, but I’ve been doing it for ages. I did it first! There were also some courses on really odd programming languages, a bit of Prolog, a little bit of C. Having a little bit of each of those is something that I would have never done on my own, so it was important. And then there are knowledge-based courses which are about not programming itself but things that have been programmed like TCP. Those are really important for examples for how to approach things. Did you do any internships while you were at university? Yeah, I spent both of my summers at the same company. I thought I could code well before I went there. Looking back at the crap that I produced, it was only surpassed in its crappiness by all of the other code already in that company. I’m so much better at writing nice code now than I used to be back then. Was there just not a culture of looking after your code? There was, they just didn’t hire people for their abilities in that area. They hired people for raw IQ. The first indicator of it going wrong was that they didn’t have any computer scientists, which is a bit odd in a programming company. But even beyond that they didn’t have people who learnt architecture from anyone else. Most of them had started straight out of university, so never really had experience or mentors to learn from. There wasn’t the experience to draw from to teach each other. In the second half of my second internship, I was being given tasks like looking at new technologies and teaching people stuff. Interns shouldn’t be teaching people how to do their jobs! All interns are going to have little nuggets of things that you don’t know about, but they shouldn’t consistently be the ones who know the most. It’s not a good environment to learn. I was going to ask how you found working with people who were more experienced than you… When I reached Red Gate, I found some people who were more experienced programmers than me, and that was difficult. I’ve been coding since I was tiny. At university there were people who were cleverer than me, but there weren’t very many who were more experienced programmers than me. During my internship, I didn’t find anyone who I classed as being a noticeably more experienced programmer than me. So, it was a shock to the system to have valid criticisms rather than just formatting criticisms. However, Red Gate’s not so big on the actual code review, at least it wasn’t when I started. We did an entire product release and then somebody looked over all of the UI of that product which I’d written and say what they didn’t like. By that point, it was way too late and I’d disagree with them. Do you think the lack of code reviews was a bad thing? I think if there’s going to be any oversight of new people, then it should be continuous rather than chunky. For me I don’t mind too much, I could go out and get oversight if I wanted it, and in those situations I felt comfortable without it. If I was managing the new person, then maybe I’d be keener on oversight and then the right way to do it is continuously and in very, very small chunks. Have you had any significant projects you’ve worked on outside of a job? When I was a teenager I wrote all sorts of stuff. I used to write games, I derived how to do isomorphic projections myself once. I didn’t know what the word was so I couldn’t Google for it, so I worked it out myself. It was horrifically complicated. But it sort of tailed off when I started at university, and is now basically zero. If I do side-projects now, they tend to be work-related side projects like my actors framework, NAct, which I started in a down tools week. Could you explain a little more about NAct? It is a little C# framework for writing parallel code more easily. Parallel programming is difficult when you need to write to shared data. Sometimes parallel programming is easy because you don’t need to write to shared data. When you do need to access shared data, you could just have your threads pile in and do their work, but then you would screw up the data because the threads would trample on each other’s toes. You could lock, but locks are really dangerous if you’re using more than one of them. You get interactions like deadlocks, and that’s just nasty. Actors instead allows you to say this piece of data belongs to this thread of execution, and nobody else can read it. If you want to read it, then ask that thread of execution for a piece of it by sending a message, and it will send the data back by a message. And that avoids deadlocks as long as you follow some obvious rules about not making your actors sit around waiting for other actors to do something. There are lots of ways to write actors, NAct allows you to do it as if it was method calls on other objects, which means you get all the strong type-safety that C# programmers like. Do you think that this is suitable for the majority of parallel programming, or do you think it’s only suitable for specific cases? It’s suitable for most difficult parallel programming. If you’ve just got a hundred web requests which are all independent of each other, then I wouldn’t bother because it’s easier to just spin them up in separate threads and they can proceed independently of each other. But where you’ve got difficult parallel programming, where you’ve got multiple threads accessing multiple bits of data in multiple ways at different times, then actors is at least as good as all other ways, and is, I reckon, easier to think about. When you’re using actors, you presumably still have to write your code in a different way from you would otherwise using single-threaded code. You can’t use actors with any methods that have return types, because you’re not allowed to call into another actor and wait for it. If you want to get a piece of data out of another actor, then you’ve got to use tasks so that you can use “async” and “await” to await asynchronously for it. But other than that, you can still stick things in classes so it’s not too different really. Rather than having thousands of objects with mutable state, you can use component-orientated design, where there are only a few mutable classes which each have a small number of instances. Then there can be thousands of immutable objects. If you tend to do that anyway, then actors isn’t much of a jump. If I’ve already built my system without any parallelism, how hard is it to add actors to exploit all eight cores on my desktop? Usually pretty easy. If you can identify even one boundary where things look like messages and you have components where some objects live on one side and these other objects live on the other side, then you can have a granddaddy object on one side be an actor and it will parallelise as it goes across that boundary. Not too difficult. If we do get 1000-core desktop PCs, do you think actors will scale up? It’s hard. There are always in the order of twenty to fifty actors in my whole program because I tend to write each component as actors, and I tend to have one instance of each component. So this won’t scale to a thousand cores. What you can do is write data structures out of actors. I use dictionaries all over the place, and if you need a dictionary that is going to be accessed concurrently, then you could build one of those out of actors in no time. You can use queuing to marshal requests between different slices of the dictionary which are living on different threads. So it’s like a distributed hash table but all of the chunks of it are on the same machine. That means that each of these thousand processors has cached one small piece of the dictionary. I reckon it wouldn’t be too big a leap to start doing proper parallelism. Do you think it helps if actors get baked into the language, similarly to Erlang? Erlang is excellent in that it has thread-local garbage collection. C# doesn’t, so there’s a limit to how well C# actors can possibly scale because there’s a single garbage collected heap shared between all of them. When you do a global garbage collection, you’ve got to stop all of the actors, which is seriously expensive, whereas in Erlang garbage collections happen per-actor, so they’re insanely cheap. However, Erlang deviated from all the sensible language design that people have used recently and has just come up with crazy stuff. You can definitely retrofit thread-local garbage collection to .NET, and then it’s quite well-suited to support actors, even if it’s not baked into the language. Speaking of language design, do you have a favourite programming language? I’ll choose a language which I’ve never written before. I like the idea of Scala. It sounds like C#, only with some of the niggles gone. I enjoy writing static types. It means you don’t have to writing tests so much. When you say it doesn’t have some of the niggles? C# doesn’t allow the use of a property as a method group. It doesn’t have Scala case classes, or sum types, where you can do a switch statement and the compiler checks that you’ve checked all the cases, which is really useful in functional-style programming. Pattern-matching, in other words. That’s actually the major niggle. C# is pretty good, and I’m quite happy with C#. And what about going even further with the type system to remove the need for tests to something like Haskell? Or is that a step too far? I’m quite a pragmatist, I don’t think I could deal with trying to write big systems in languages with too few other users, especially when learning how to structure things. I just don’t know anyone who can teach me, and the Internet won’t teach me. That’s the main reason I wouldn’t use it. If I turned up at a company that writes big systems in Haskell, I would have no objection to that, but I wouldn’t instigate it. What about things in C#? For instance, there’s contracts in C#, so you can try to statically verify a bit more about your code. Do you think that’s useful, or just not worthwhile? I’ve not really tried it. My hunch is that it needs to be built into the language and be quite mathematical for it to work in real life, and that doesn’t seem to have ended up true for C# contracts. I don’t think anyone who’s tried them thinks they’re any good. I might be wrong. On a slightly different note, how do you like to debug code? I think I’m quite an odd debugger. I use guesswork extremely rarely, especially if something seems quite difficult to debug. I’ve been bitten spending hours and hours on guesswork and not being scientific about debugging in the past, so now I’m scientific to a fault. What I want is to see the bug happening in the debugger, to step through the bug happening. To watch the program going from a valid state to an invalid state. When there’s a bug and I can’t work out why it’s happening, I try to find some piece of evidence which places the bug in one section of the code. From that experiment, I binary chop on the possible causes of the bug. I suppose that means binary chopping on places in the code, or binary chopping on a stage through a processing cycle. Basically, I’m very stupid about how I debug. I won’t make any guesses, I won’t use any intuition, I will only identify the experiment that’s going to binary chop most effectively and repeat rather than trying to guess anything. I suppose it’s quite top-down. Is most of the time then spent in the debugger? Absolutely, if at all possible I will never debug using print statements or logs. I don’t really hold much stock in outputting logs. If there’s any bug which can be reproduced locally, I’d rather do it in the debugger than outputting logs. And with SmartAssembly error reporting, there’s not a lot that can’t be either observed in an error report and just fixed, or reproduced locally. And in those other situations, maybe I’ll use logs. But I hate using logs. You stare at the log, trying to guess what’s going on, and that’s exactly what I don’t like doing. You have to just look at it and see does this look right or wrong. We’ve covered how you get to grip with bugs. How do you get to grips with an entire codebase? I watch it in the debugger. I find little bugs and then try to fix them, and mostly do it by watching them in the debugger and gradually getting an understanding of how the code works using my process of binary chopping. I have to do a lot of reading and watching code to choose where my slicing-in-half experiment is going to be. The last time I did it was SmartAssembly. The old code was a complete mess, but at least it did things top to bottom. There wasn’t too much of some of the big abstractions where flow of control goes all over the place, into a base class and back again. Code’s really hard to understand when that happens. So I like to choose a little bug and try to fix it, and choose a bigger bug and try to fix it. Definitely learn by doing. I want to always have an aim so that I get a little achievement after every few hours of debugging. Once I’ve learnt the codebase I might be able to fix all the bugs in an hour, but I’d rather be using them as an aim while I’m learning the codebase. If I was a maintainer of a codebase, what should I do to make it as easy as possible for you to understand? Keep distinct concepts in different places. And name your stuff so that it’s obvious which concepts live there. You shouldn’t have some variable that gets set miles up the top of somewhere, and then is read miles down to choose some later behaviour. I’m talking from a very much SmartAssembly point of view because the old SmartAssembly codebase had tons and tons of these things, where it would read some property of the code and then deal with it later. Just thousands of variables in scope. Loads of things to think about. If you can keep concepts separate, then it aids me in my process of fixing bugs one at a time, because each bug is going to more or less be understandable in the one place where it is. And what about tests? Do you think they help at all? I’ve never had the opportunity to learn a codebase which has had tests, I don’t know what it’s like! What about when you’re actually developing? How useful do you find tests in finding bugs or regressions? Finding regressions, absolutely. Running bits of code that would be quite hard to run otherwise, definitely. It doesn’t happen very often that a test finds a bug in the first place. I don’t really buy nebulous promises like tests being a good way to think about the spec of the code. My thinking goes something like “This code works at the moment, great, ship it! Ah, there’s a way that this code doesn’t work. Okay, write a test, demonstrate that it doesn’t work, fix it, use the test to demonstrate that it’s now fixed, and keep the test for future regressions.” The most valuable tests are for bugs that have actually happened at some point, because bugs that have actually happened at some point, despite the fact that you think you’ve fixed them, are way more likely to appear again than new bugs are. Does that mean that when you write your code the first time, there are no tests? Often. The chance of there being a bug in a new feature is relatively unaffected by whether I’ve written a test for that new feature because I’m not good enough at writing tests to think of bugs that I would have written into the code. So not writing regression tests for all of your code hasn’t affected you too badly? There are different kinds of features. Some of them just always work, and are just not flaky, they just continue working whatever you throw at them. Maybe because the type-checker is particularly effective around them. Writing tests for those features which just tend to always work is a waste of time. And because it’s a waste of time I’ll tend to wait until a feature has demonstrated its flakiness by having bugs in it before I start trying to test it. You can get a feel for whether it’s going to be flaky code as you’re writing it. I try to write it to make it not flaky, but there are some things that are just inherently flaky. And very occasionally, I’ll think “this is going to be flaky” as I’m writing, and then maybe do a test, but not most of the time. How do you think your programming style has changed over time? I’ve got clearer about what the right way of doing things is. I used to flip-flop a lot between different ideas. Five years ago I came up with some really good ideas and some really terrible ideas. All of them seemed great when I thought of them, but they were quite diverse ideas, whereas now I have a smaller set of reliable ideas that are actually good for structuring code. So my code is probably more similar to itself than it used to be back in the day, when I was trying stuff out. I’ve got more disciplined about encapsulation, I think. There are operational things like I use actors more now than I used to, and that forces me to use immutability more than I used to. The first code that I wrote in Red Gate was the memory profiler UI, and that was an actor, I just didn’t know the name of it at the time. I don’t really use object-orientation. By object-orientation, I mean having n objects of the same type which are mutable. I want a constant number of objects that are mutable, and they should be different types. I stick stuff in dictionaries and then have one thing that owns the dictionary and puts stuff in and out of it. That’s definitely a pattern that I’ve seen recently. I think maybe I’m doing functional programming. Possibly. It’s plausible. If you had to summarise the essence of programming in a pithy sentence, how would you do it? Programming is the form of art that, without losing any of the beauty of architecture or fine art, allows you to produce things that people love and you make money from. So you think it’s an art rather than a science? It’s a little bit of engineering, a smidgeon of maths, but it’s not science. Like architecture, programming is on that boundary between art and engineering. If you want to do it really nicely, it’s mostly art. You can get away with doing architecture and programming entirely by having a good engineering mind, but you’re not going to produce anything nice. You’re not going to have joy doing it if you’re an engineering mind. Architects who are just engineering minds are not going to enjoy their job. I suppose engineering is the foundation on which you build the art. Exactly. How do you think programming is going to change over the next ten years? There will be an unfortunate shift towards dynamically-typed languages, because of JavaScript. JavaScript has an unfair advantage. JavaScript’s unfair advantage will cause more people to be exposed to dynamically-typed languages, which means other dynamically-typed languages crop up and the best features go into dynamically-typed languages. Then people conflate the good features with the fact that it’s dynamically-typed, and more investment goes into dynamically-typed languages. They end up better, so people use them. What about the idea of compiling other languages, possibly statically-typed, to JavaScript? It’s a reasonable idea. I would like to do it, but I don’t think enough people in the world are going to do it to make it pick up. The hordes of beginners are the lifeblood of a language community. They are what makes there be good tools and what makes there be vibrant community websites. And any particular thing which is the same as JavaScript only with extra stuff added to it, although it might be technically great, is not going to have the hordes of beginners. JavaScript is always to be quickest and easiest way for a beginner to start programming in the browser. And dynamically-typed languages are great for beginners. Compilers are pretty scary and beginners don’t write big code. And having your errors come up in the same place, whether they’re statically checkable errors or not, is quite nice for a beginner. If someone asked me to teach them some programming, I’d teach them JavaScript. If dynamically-typed languages are great for beginners, when do you think the benefits of static typing start to kick in? The value of having a statically typed program is in the tools that rely on the static types to produce a smooth IDE experience rather than actually telling me my compile errors. And only once you’re experienced enough a programmer that having a really smooth IDE experience makes a blind bit of difference, does static typing make a blind bit of difference. So it’s not really about size of codebase. If I go and write up a tiny program, I’m still going to get value out of writing it in C# using ReSharper because I’m experienced with C# and ReSharper enough to be able to write code five times faster if I have that help. Any other visions of the future? Nobody’s going to use actors. Because everyone’s going to be running on single-core VMs connected over network-ready protocols like JSON over HTTP. So, parallelism within one operating system is going to die. But until then, you should use actors. More Red Gater Coder interviews

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  • value types in the vm

    - by john.rose
    value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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  • Did I lose my RAID again?

    - by BarsMonster
    Hi! A little history: 2 years ago I was really excited to find out that mdadm is so powerful that it even can reshape arrays, so you can start with a smaller array and then grow it as you need. I've bought 3x1Tb drives and made a RAID-5. It was fine for a year. Then I bought 2x more, and tried to reshape to RAID-6 out of 5 drives, and due to some mess with superblock versions, lost all content. Had to rebuild it from scratch, but 2Tb of data were gone. Yesterday I bought 2 more drives, and this time I had everything: properly built array, UPS. I've disabled write intent map, added 2 new drives as spares and run a command to grow array to 7-disks. It started working, but speed was ridiculously slow, ~100kb/sec. After processing first 37Mb at such an amazing speed, one of old HDDs fails. I properly shutdown the PC and disconnected the failed drive. After bootup it appeared that it recreated the intent map as it was still in mdadm config, so I removed it from config and rebooted again. Now all I see is that all mdadm processes deadlock, and don't do anything. PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1937 root 20 0 12992 608 444 D 0 0.1 0:00.00 mdadm 2283 root 20 0 12992 852 704 D 0 0.1 0:00.01 mdadm 2287 root 20 0 0 0 0 D 0 0.0 0:00.01 md0_reshape 2288 root 18 -2 12992 820 676 D 0 0.1 0:00.01 mdadm And all I see in mdstat is: $ cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid6 sdb1[1] sdg1[4] sdf1[7] sde1[6] sdd1[0] sdc1[5] 2929683456 blocks super 1.2 level 6, 1024k chunk, algorithm 2 [7/6] [UU_UUUU] [>....................] reshape = 0.0% (37888/976561152) finish=567604147.2min speed=0K/sec I've already tried mdadm 2.6.7, 3.1.4 and 3.2 - nothing helps. Did I lose my data again? Any suggestions on how can I make this work? OS is Ubuntu Server 10.04.2. PS. Needless to say, the data is inaccessible - I cannot mount /dev/md0 to save the most valuable data. You can see my disappointment - the very specific thing I was excited about failed twice taking 5Tb of my data with it. Update: It appears there is some nice info in kern.log: 21:38:48 ...: [ 166.522055] raid5: reshape will continue 21:38:48 ...: [ 166.522085] raid5: device sdb1 operational as raid disk 1 21:38:48 ...: [ 166.522091] raid5: device sdg1 operational as raid disk 4 21:38:48 ...: [ 166.522097] raid5: device sdf1 operational as raid disk 5 21:38:48 ...: [ 166.522102] raid5: device sde1 operational as raid disk 6 21:38:48 ...: [ 166.522107] raid5: device sdd1 operational as raid disk 0 21:38:48 ...: [ 166.522111] raid5: device sdc1 operational as raid disk 3 21:38:48 ...: [ 166.523942] raid5: allocated 7438kB for md0 21:38:48 ...: [ 166.524041] 1: w=1 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524050] 4: w=2 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524056] 5: w=3 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524062] 6: w=4 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524068] 0: w=5 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524073] 3: w=6 pa=2 pr=5 m=2 a=2 r=7 op1=0 op2=0 21:38:48 ...: [ 166.524079] raid5: raid level 6 set md0 active with 6 out of 7 devices, algorithm 2 21:38:48 ...: [ 166.524519] RAID5 conf printout: 21:38:48 ...: [ 166.524523] --- rd:7 wd:6 21:38:48 ...: [ 166.524528] disk 0, o:1, dev:sdd1 21:38:48 ...: [ 166.524532] disk 1, o:1, dev:sdb1 21:38:48 ...: [ 166.524537] disk 3, o:1, dev:sdc1 21:38:48 ...: [ 166.524541] disk 4, o:1, dev:sdg1 21:38:48 ...: [ 166.524545] disk 5, o:1, dev:sdf1 21:38:48 ...: [ 166.524550] disk 6, o:1, dev:sde1 21:38:48 ...: [ 166.524553] ...ok start reshape thread 21:38:48 ...: [ 166.524727] md0: detected capacity change from 0 to 2999995858944 21:38:48 ...: [ 166.524735] md: reshape of RAID array md0 21:38:48 ...: [ 166.524740] md: minimum _guaranteed_ speed: 1000 KB/sec/disk. 21:38:48 ...: [ 166.524745] md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reshape. 21:38:48 ...: [ 166.524756] md: using 128k window, over a total of 976561152 blocks. 21:39:05 ...: [ 166.525013] md0: 21:42:04 ...: [ 362.520063] INFO: task mdadm:1937 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520068] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520073] mdadm D 00000000ffffffff 0 1937 1 0x00000000 21:42:04 ...: [ 362.520083] ffff88002ef4f5d8 0000000000000082 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520092] ffff88002eb5b198 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5ade0 21:42:04 ...: [ 362.520100] 0000000000015bc0 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5b198 21:42:04 ...: [ 362.520107] Call Trace: 21:42:04 ...: [ 362.520133] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:42:04 ...: [ 362.520148] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:42:04 ...: [ 362.520159] [<ffffffffa0228413>] make_request+0x243/0x4b0 [raid456] 21:42:04 ...: [ 362.520169] [<ffffffffa0221a90>] ? release_stripe+0x50/0x70 [raid456] 21:42:04 ...: [ 362.520179] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:42:04 ...: [ 362.520188] [<ffffffff81414df0>] md_make_request+0xc0/0x130 21:42:04 ...: [ 362.520194] [<ffffffff81414df0>] ? md_make_request+0xc0/0x130 21:42:04 ...: [ 362.520205] [<ffffffff8129f8c1>] generic_make_request+0x1b1/0x4f0 21:42:04 ...: [ 362.520214] [<ffffffff810f6515>] ? mempool_alloc_slab+0x15/0x20 21:42:04 ...: [ 362.520222] [<ffffffff8116c2ec>] ? alloc_buffer_head+0x1c/0x60 21:42:04 ...: [ 362.520230] [<ffffffff8129fc80>] submit_bio+0x80/0x110 21:42:04 ...: [ 362.520236] [<ffffffff8116c849>] submit_bh+0xf9/0x140 21:42:04 ...: [ 362.520244] [<ffffffff8116f124>] block_read_full_page+0x274/0x3b0 21:42:04 ...: [ 362.520251] [<ffffffff81172c90>] ? blkdev_get_block+0x0/0x70 21:42:04 ...: [ 362.520258] [<ffffffff8110d875>] ? __inc_zone_page_state+0x35/0x40 21:42:04 ...: [ 362.520265] [<ffffffff810f46d8>] ? add_to_page_cache_locked+0xe8/0x160 21:42:04 ...: [ 362.520272] [<ffffffff81173d78>] blkdev_readpage+0x18/0x20 21:42:04 ...: [ 362.520279] [<ffffffff810f484b>] __read_cache_page+0x7b/0xe0 21:42:04 ...: [ 362.520285] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:42:04 ...: [ 362.520290] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:42:04 ...: [ 362.520297] [<ffffffff810f57dc>] do_read_cache_page+0x3c/0x120 21:42:04 ...: [ 362.520304] [<ffffffff810f5909>] read_cache_page_async+0x19/0x20 21:42:04 ...: [ 362.520310] [<ffffffff810f591e>] read_cache_page+0xe/0x20 21:42:04 ...: [ 362.520317] [<ffffffff811a6cb0>] read_dev_sector+0x30/0xa0 21:42:04 ...: [ 362.520324] [<ffffffff811a7fcd>] amiga_partition+0x6d/0x460 21:42:04 ...: [ 362.520331] [<ffffffff811a7938>] check_partition+0x138/0x190 21:42:04 ...: [ 362.520338] [<ffffffff811a7a7a>] rescan_partitions+0xea/0x2f0 21:42:04 ...: [ 362.520344] [<ffffffff811744c7>] __blkdev_get+0x267/0x3d0 21:42:04 ...: [ 362.520350] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:42:04 ...: [ 362.520356] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:42:04 ...: [ 362.520362] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:42:04 ...: [ 362.520369] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:42:04 ...: [ 362.520377] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:42:04 ...: [ 362.520385] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:42:04 ...: [ 362.520391] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:42:04 ...: [ 362.520398] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:42:04 ...: [ 362.520406] [<ffffffff811134a8>] ? unmap_vmas+0x178/0x310 21:42:04 ...: [ 362.520414] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:42:04 ...: [ 362.520421] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:42:04 ...: [ 362.520428] [<ffffffff811418b0>] sys_open+0x20/0x30 21:42:04 ...: [ 362.520437] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:42:04 ...: [ 362.520446] INFO: task mdadm:2283 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520450] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520454] mdadm D 0000000000000000 0 2283 2212 0x00000000 21:42:04 ...: [ 362.520462] ffff88002cca7d98 0000000000000086 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520470] ffff88002ededf78 ffff88002cca7fd8 0000000000015bc0 ffff88002ededbc0 21:42:04 ...: [ 362.520478] 0000000000015bc0 ffff88002cca7fd8 0000000000015bc0 ffff88002ededf78 21:42:04 ...: [ 362.520485] Call Trace: 21:42:04 ...: [ 362.520495] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:42:04 ...: [ 362.520502] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:42:04 ...: [ 362.520508] [<ffffffff8117404d>] __blkdev_put+0x3d/0x190 21:42:04 ...: [ 362.520514] [<ffffffff811741b0>] blkdev_put+0x10/0x20 21:42:04 ...: [ 362.520520] [<ffffffff811741f3>] blkdev_close+0x33/0x60 21:42:04 ...: [ 362.520527] [<ffffffff81145375>] __fput+0xf5/0x210 21:42:04 ...: [ 362.520534] [<ffffffff811454b5>] fput+0x25/0x30 21:42:04 ...: [ 362.520540] [<ffffffff811415ad>] filp_close+0x5d/0x90 21:42:04 ...: [ 362.520546] [<ffffffff81141697>] sys_close+0xb7/0x120 21:42:04 ...: [ 362.520553] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:42:04 ...: [ 362.520559] INFO: task md0_reshape:2287 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520563] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520567] md0_reshape D ffff88003aee96f0 0 2287 2 0x00000000 21:42:04 ...: [ 362.520575] ffff88003cf05a70 0000000000000046 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520582] ffff88003aee9aa8 ffff88003cf05fd8 0000000000015bc0 ffff88003aee96f0 21:42:04 ...: [ 362.520590] 0000000000015bc0 ffff88003cf05fd8 0000000000015bc0 ffff88003aee9aa8 21:42:04 ...: [ 362.520597] Call Trace: 21:42:04 ...: [ 362.520608] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:42:04 ...: [ 362.520616] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:42:04 ...: [ 362.520626] [<ffffffffa0226f80>] reshape_request+0x4c0/0x9a0 [raid456] 21:42:04 ...: [ 362.520634] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:42:04 ...: [ 362.520644] [<ffffffffa022777a>] sync_request+0x31a/0x3a0 [raid456] 21:42:04 ...: [ 362.520651] [<ffffffff81052713>] ? __wake_up+0x53/0x70 21:42:04 ...: [ 362.520658] [<ffffffff814156b1>] md_do_sync+0x621/0xbb0 21:42:04 ...: [ 362.520668] [<ffffffff810387b9>] ? default_spin_lock_flags+0x9/0x10 21:42:04 ...: [ 362.520675] [<ffffffff8141640c>] md_thread+0x5c/0x130 21:42:04 ...: [ 362.520681] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:42:04 ...: [ 362.520688] [<ffffffff814163b0>] ? md_thread+0x0/0x130 21:42:04 ...: [ 362.520694] [<ffffffff81084416>] kthread+0x96/0xa0 21:42:04 ...: [ 362.520701] [<ffffffff810131ea>] child_rip+0xa/0x20 21:42:04 ...: [ 362.520707] [<ffffffff81084380>] ? kthread+0x0/0xa0 21:42:04 ...: [ 362.520713] [<ffffffff810131e0>] ? child_rip+0x0/0x20 21:42:04 ...: [ 362.520718] INFO: task mdadm:2288 blocked for more than 120 seconds. 21:42:04 ...: [ 362.520721] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:42:04 ...: [ 362.520725] mdadm D 0000000000000000 0 2288 1 0x00000000 21:42:04 ...: [ 362.520733] ffff88002cca9c18 0000000000000086 0000000000015bc0 0000000000015bc0 21:42:04 ...: [ 362.520741] ffff88003aee83b8 ffff88002cca9fd8 0000000000015bc0 ffff88003aee8000 21:42:04 ...: [ 362.520748] 0000000000015bc0 ffff88002cca9fd8 0000000000015bc0 ffff88003aee83b8 21:42:04 ...: [ 362.520755] Call Trace: 21:42:04 ...: [ 362.520763] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:42:04 ...: [ 362.520771] [<ffffffff812a6d50>] ? exact_match+0x0/0x10 21:42:04 ...: [ 362.520777] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:42:04 ...: [ 362.520783] [<ffffffff811742c8>] __blkdev_get+0x68/0x3d0 21:42:04 ...: [ 362.520790] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:42:04 ...: [ 362.520795] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:42:04 ...: [ 362.520801] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:42:04 ...: [ 362.520808] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:42:04 ...: [ 362.520815] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:42:04 ...: [ 362.520821] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:42:04 ...: [ 362.520828] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:42:04 ...: [ 362.520834] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:42:04 ...: [ 362.520841] [<ffffffff810ff0e1>] ? lru_cache_add_lru+0x21/0x40 21:42:04 ...: [ 362.520848] [<ffffffff8111109c>] ? do_anonymous_page+0x11c/0x330 21:42:04 ...: [ 362.520855] [<ffffffff81115d5f>] ? handle_mm_fault+0x31f/0x3c0 21:42:04 ...: [ 362.520862] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:42:04 ...: [ 362.520868] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:42:04 ...: [ 362.520874] [<ffffffff811418b0>] sys_open+0x20/0x30 21:42:04 ...: [ 362.520882] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:44:04 ...: [ 482.520065] INFO: task mdadm:1937 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520071] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520077] mdadm D 00000000ffffffff 0 1937 1 0x00000000 21:44:04 ...: [ 482.520087] ffff88002ef4f5d8 0000000000000082 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520096] ffff88002eb5b198 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5ade0 21:44:04 ...: [ 482.520104] 0000000000015bc0 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5b198 21:44:04 ...: [ 482.520112] Call Trace: 21:44:04 ...: [ 482.520139] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:44:04 ...: [ 482.520154] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:44:04 ...: [ 482.520165] [<ffffffffa0228413>] make_request+0x243/0x4b0 [raid456] 21:44:04 ...: [ 482.520175] [<ffffffffa0221a90>] ? release_stripe+0x50/0x70 [raid456] 21:44:04 ...: [ 482.520185] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:44:04 ...: [ 482.520194] [<ffffffff81414df0>] md_make_request+0xc0/0x130 21:44:04 ...: [ 482.520201] [<ffffffff81414df0>] ? md_make_request+0xc0/0x130 21:44:04 ...: [ 482.520212] [<ffffffff8129f8c1>] generic_make_request+0x1b1/0x4f0 21:44:04 ...: [ 482.520221] [<ffffffff810f6515>] ? mempool_alloc_slab+0x15/0x20 21:44:04 ...: [ 482.520229] [<ffffffff8116c2ec>] ? alloc_buffer_head+0x1c/0x60 21:44:04 ...: [ 482.520237] [<ffffffff8129fc80>] submit_bio+0x80/0x110 21:44:04 ...: [ 482.520244] [<ffffffff8116c849>] submit_bh+0xf9/0x140 21:44:04 ...: [ 482.520252] [<ffffffff8116f124>] block_read_full_page+0x274/0x3b0 21:44:04 ...: [ 482.520258] [<ffffffff81172c90>] ? blkdev_get_block+0x0/0x70 21:44:04 ...: [ 482.520266] [<ffffffff8110d875>] ? __inc_zone_page_state+0x35/0x40 21:44:04 ...: [ 482.520273] [<ffffffff810f46d8>] ? add_to_page_cache_locked+0xe8/0x160 21:44:04 ...: [ 482.520280] [<ffffffff81173d78>] blkdev_readpage+0x18/0x20 21:44:04 ...: [ 482.520286] [<ffffffff810f484b>] __read_cache_page+0x7b/0xe0 21:44:04 ...: [ 482.520293] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:44:04 ...: [ 482.520299] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:44:04 ...: [ 482.520306] [<ffffffff810f57dc>] do_read_cache_page+0x3c/0x120 21:44:04 ...: [ 482.520313] [<ffffffff810f5909>] read_cache_page_async+0x19/0x20 21:44:04 ...: [ 482.520319] [<ffffffff810f591e>] read_cache_page+0xe/0x20 21:44:04 ...: [ 482.520327] [<ffffffff811a6cb0>] read_dev_sector+0x30/0xa0 21:44:04 ...: [ 482.520334] [<ffffffff811a7fcd>] amiga_partition+0x6d/0x460 21:44:04 ...: [ 482.520341] [<ffffffff811a7938>] check_partition+0x138/0x190 21:44:04 ...: [ 482.520348] [<ffffffff811a7a7a>] rescan_partitions+0xea/0x2f0 21:44:04 ...: [ 482.520355] [<ffffffff811744c7>] __blkdev_get+0x267/0x3d0 21:44:04 ...: [ 482.520361] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:44:04 ...: [ 482.520367] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:44:04 ...: [ 482.520373] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:44:04 ...: [ 482.520380] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:44:04 ...: [ 482.520388] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:44:04 ...: [ 482.520396] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:44:04 ...: [ 482.520403] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:44:04 ...: [ 482.520410] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:44:04 ...: [ 482.520417] [<ffffffff811134a8>] ? unmap_vmas+0x178/0x310 21:44:04 ...: [ 482.520426] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:44:04 ...: [ 482.520432] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:44:04 ...: [ 482.520438] [<ffffffff811418b0>] sys_open+0x20/0x30 21:44:04 ...: [ 482.520447] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:44:04 ...: [ 482.520458] INFO: task mdadm:2283 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520462] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520467] mdadm D 0000000000000000 0 2283 2212 0x00000000 21:44:04 ...: [ 482.520475] ffff88002cca7d98 0000000000000086 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520483] ffff88002ededf78 ffff88002cca7fd8 0000000000015bc0 ffff88002ededbc0 21:44:04 ...: [ 482.520490] 0000000000015bc0 ffff88002cca7fd8 0000000000015bc0 ffff88002ededf78 21:44:04 ...: [ 482.520498] Call Trace: 21:44:04 ...: [ 482.520508] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:44:04 ...: [ 482.520515] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:44:04 ...: [ 482.520521] [<ffffffff8117404d>] __blkdev_put+0x3d/0x190 21:44:04 ...: [ 482.520527] [<ffffffff811741b0>] blkdev_put+0x10/0x20 21:44:04 ...: [ 482.520533] [<ffffffff811741f3>] blkdev_close+0x33/0x60 21:44:04 ...: [ 482.520541] [<ffffffff81145375>] __fput+0xf5/0x210 21:44:04 ...: [ 482.520547] [<ffffffff811454b5>] fput+0x25/0x30 21:44:04 ...: [ 482.520554] [<ffffffff811415ad>] filp_close+0x5d/0x90 21:44:04 ...: [ 482.520560] [<ffffffff81141697>] sys_close+0xb7/0x120 21:44:04 ...: [ 482.520568] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:44:04 ...: [ 482.520574] INFO: task md0_reshape:2287 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520578] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520582] md0_reshape D ffff88003aee96f0 0 2287 2 0x00000000 21:44:04 ...: [ 482.520590] ffff88003cf05a70 0000000000000046 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520597] ffff88003aee9aa8 ffff88003cf05fd8 0000000000015bc0 ffff88003aee96f0 21:44:04 ...: [ 482.520605] 0000000000015bc0 ffff88003cf05fd8 0000000000015bc0 ffff88003aee9aa8 21:44:04 ...: [ 482.520612] Call Trace: 21:44:04 ...: [ 482.520623] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:44:04 ...: [ 482.520633] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:44:04 ...: [ 482.520643] [<ffffffffa0226f80>] reshape_request+0x4c0/0x9a0 [raid456] 21:44:04 ...: [ 482.520651] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:44:04 ...: [ 482.520661] [<ffffffffa022777a>] sync_request+0x31a/0x3a0 [raid456] 21:44:04 ...: [ 482.520668] [<ffffffff81052713>] ? __wake_up+0x53/0x70 21:44:04 ...: [ 482.520675] [<ffffffff814156b1>] md_do_sync+0x621/0xbb0 21:44:04 ...: [ 482.520685] [<ffffffff810387b9>] ? default_spin_lock_flags+0x9/0x10 21:44:04 ...: [ 482.520692] [<ffffffff8141640c>] md_thread+0x5c/0x130 21:44:04 ...: [ 482.520699] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:44:04 ...: [ 482.520705] [<ffffffff814163b0>] ? md_thread+0x0/0x130 21:44:04 ...: [ 482.520711] [<ffffffff81084416>] kthread+0x96/0xa0 21:44:04 ...: [ 482.520718] [<ffffffff810131ea>] child_rip+0xa/0x20 21:44:04 ...: [ 482.520725] [<ffffffff81084380>] ? kthread+0x0/0xa0 21:44:04 ...: [ 482.520730] [<ffffffff810131e0>] ? child_rip+0x0/0x20 21:44:04 ...: [ 482.520735] INFO: task mdadm:2288 blocked for more than 120 seconds. 21:44:04 ...: [ 482.520739] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:44:04 ...: [ 482.520743] mdadm D 0000000000000000 0 2288 1 0x00000000 21:44:04 ...: [ 482.520751] ffff88002cca9c18 0000000000000086 0000000000015bc0 0000000000015bc0 21:44:04 ...: [ 482.520759] ffff88003aee83b8 ffff88002cca9fd8 0000000000015bc0 ffff88003aee8000 21:44:04 ...: [ 482.520767] 0000000000015bc0 ffff88002cca9fd8 0000000000015bc0 ffff88003aee83b8 21:44:04 ...: [ 482.520774] Call Trace: 21:44:04 ...: [ 482.520782] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:44:04 ...: [ 482.520790] [<ffffffff812a6d50>] ? exact_match+0x0/0x10 21:44:04 ...: [ 482.520797] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:44:04 ...: [ 482.520804] [<ffffffff811742c8>] __blkdev_get+0x68/0x3d0 21:44:04 ...: [ 482.520810] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:44:04 ...: [ 482.520816] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:44:04 ...: [ 482.520822] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:44:04 ...: [ 482.520829] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:44:04 ...: [ 482.520837] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:44:04 ...: [ 482.520843] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:44:04 ...: [ 482.520850] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:44:04 ...: [ 482.520857] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:44:04 ...: [ 482.520864] [<ffffffff810ff0e1>] ? lru_cache_add_lru+0x21/0x40 21:44:04 ...: [ 482.520871] [<ffffffff8111109c>] ? do_anonymous_page+0x11c/0x330 21:44:04 ...: [ 482.520878] [<ffffffff81115d5f>] ? handle_mm_fault+0x31f/0x3c0 21:44:04 ...: [ 482.520885] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:44:04 ...: [ 482.520891] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:44:04 ...: [ 482.520897] [<ffffffff811418b0>] sys_open+0x20/0x30 21:44:04 ...: [ 482.520905] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:46:04 ...: [ 602.520053] INFO: task mdadm:1937 blocked for more than 120 seconds. 21:46:04 ...: [ 602.520059] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:46:04 ...: [ 602.520065] mdadm D 00000000ffffffff 0 1937 1 0x00000000 21:46:04 ...: [ 602.520075] ffff88002ef4f5d8 0000000000000082 0000000000015bc0 0000000000015bc0 21:46:04 ...: [ 602.520084] ffff88002eb5b198 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5ade0 21:46:04 ...: [ 602.520091] 0000000000015bc0 ffff88002ef4ffd8 0000000000015bc0 ffff88002eb5b198 21:46:04 ...: [ 602.520099] Call Trace: 21:46:04 ...: [ 602.520127] [<ffffffffa0224892>] get_active_stripe+0x312/0x3f0 [raid456] 21:46:04 ...: [ 602.520142] [<ffffffff81059ae0>] ? default_wake_function+0x0/0x20 21:46:04 ...: [ 602.520153] [<ffffffffa0228413>] make_request+0x243/0x4b0 [raid456] 21:46:04 ...: [ 602.520162] [<ffffffffa0221a90>] ? release_stripe+0x50/0x70 [raid456] 21:46:04 ...: [ 602.520171] [<ffffffff81084790>] ? autoremove_wake_function+0x0/0x40 21:46:04 ...: [ 602.520180] [<ffffffff81414df0>] md_make_request+0xc0/0x130 21:46:04 ...: [ 602.520187] [<ffffffff81414df0>] ? md_make_request+0xc0/0x130 21:46:04 ...: [ 602.520197] [<ffffffff8129f8c1>] generic_make_request+0x1b1/0x4f0 21:46:04 ...: [ 602.520206] [<ffffffff810f6515>] ? mempool_alloc_slab+0x15/0x20 21:46:04 ...: [ 602.520215] [<ffffffff8116c2ec>] ? alloc_buffer_head+0x1c/0x60 21:46:04 ...: [ 602.520222] [<ffffffff8129fc80>] submit_bio+0x80/0x110 21:46:04 ...: [ 602.520229] [<ffffffff8116c849>] submit_bh+0xf9/0x140 21:46:04 ...: [ 602.520237] [<ffffffff8116f124>] block_read_full_page+0x274/0x3b0 21:46:04 ...: [ 602.520244] [<ffffffff81172c90>] ? blkdev_get_block+0x0/0x70 21:46:04 ...: [ 602.520252] [<ffffffff8110d875>] ? __inc_zone_page_state+0x35/0x40 21:46:04 ...: [ 602.520259] [<ffffffff810f46d8>] ? add_to_page_cache_locked+0xe8/0x160 21:46:04 ...: [ 602.520266] [<ffffffff81173d78>] blkdev_readpage+0x18/0x20 21:46:04 ...: [ 602.520273] [<ffffffff810f484b>] __read_cache_page+0x7b/0xe0 21:46:04 ...: [ 602.520279] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:46:04 ...: [ 602.520285] [<ffffffff81173d60>] ? blkdev_readpage+0x0/0x20 21:46:04 ...: [ 602.520292] [<ffffffff810f57dc>] do_read_cache_page+0x3c/0x120 21:46:04 ...: [ 602.520300] [<ffffffff810f5909>] read_cache_page_async+0x19/0x20 21:46:04 ...: [ 602.520306] [<ffffffff810f591e>] read_cache_page+0xe/0x20 21:46:04 ...: [ 602.520314] [<ffffffff811a6cb0>] read_dev_sector+0x30/0xa0 21:46:04 ...: [ 602.520321] [<ffffffff811a7fcd>] amiga_partition+0x6d/0x460 21:46:04 ...: [ 602.520328] [<ffffffff811a7938>] check_partition+0x138/0x190 21:46:04 ...: [ 602.520335] [<ffffffff811a7a7a>] rescan_partitions+0xea/0x2f0 21:46:04 ...: [ 602.520342] [<ffffffff811744c7>] __blkdev_get+0x267/0x3d0 21:46:04 ...: [ 602.520348] [<ffffffff81174650>] ? blkdev_open+0x0/0xc0 21:46:04 ...: [ 602.520354] [<ffffffff81174640>] blkdev_get+0x10/0x20 21:46:04 ...: [ 602.520359] [<ffffffff811746c1>] blkdev_open+0x71/0xc0 21:46:04 ...: [ 602.520367] [<ffffffff811419f3>] __dentry_open+0x113/0x370 21:46:04 ...: [ 602.520375] [<ffffffff81253f8f>] ? security_inode_permission+0x1f/0x30 21:46:04 ...: [ 602.520383] [<ffffffff8114de3f>] ? inode_permission+0xaf/0xd0 21:46:04 ...: [ 602.520390] [<ffffffff81141d67>] nameidata_to_filp+0x57/0x70 21:46:04 ...: [ 602.520397] [<ffffffff8115207a>] do_filp_open+0x2da/0xba0 21:46:04 ...: [ 602.520404] [<ffffffff811134a8>] ? unmap_vmas+0x178/0x310 21:46:04 ...: [ 602.520413] [<ffffffff8115dbfa>] ? alloc_fd+0x10a/0x150 21:46:04 ...: [ 602.520419] [<ffffffff81141769>] do_sys_open+0x69/0x170 21:46:04 ...: [ 602.520425] [<ffffffff811418b0>] sys_open+0x20/0x30 21:46:04 ...: [ 602.520434] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b 21:46:04 ...: [ 602.520443] INFO: task mdadm:2283 blocked for more than 120 seconds. 21:46:04 ...: [ 602.520447] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. 21:46:04 ...: [ 602.520451] mdadm D 0000000000000000 0 2283 2212 0x00000000 21:46:04 ...: [ 602.520460] ffff88002cca7d98 0000000000000086 0000000000015bc0 0000000000015bc0 21:46:04 ...: [ 602.520468] ffff88002ededf78 ffff88002cca7fd8 0000000000015bc0 ffff88002ededbc0 21:46:04 ...: [ 602.520475] 0000000000015bc0 ffff88002cca7fd8 0000000000015bc0 ffff88002ededf78 21:46:04 ...: [ 602.520483] Call Trace: 21:46:04 ...: [ 602.520492] [<ffffffff81543a97>] __mutex_lock_slowpath+0xf7/0x180 21:46:04 ...: [ 602.520500] [<ffffffff8154397b>] mutex_lock+0x2b/0x50 21:46:04 ...: [ 602.520506] [<ffffffff8117404d>] __blkdev_put+0x3d/0x190 21:46:04 ...: [ 602.520512] [<ffffffff811741b0>] blkdev_put+0x10/0x20 21:46:04 ...: [ 602.520518] [<ffffffff811741f3>] blkdev_close+0x33/0x60 21:46:04 ...: [ 602.520526] [<ffffffff81145375>] __fput+0xf5/0x210 21:46:04 ...: [ 602.520533] [<ffffffff811454b5>] fput+0x25/0x30 21:46:04 ...: [ 602.520539] [<ffffffff811415ad>] filp_close+0x5d/0x90 21:46:04 ...: [ 602.520545] [<ffffffff81141697>] sys_close+0xb7/0x120 21:46:04 ...: [ 602.520552] [<ffffffff810121b2>] system_call_fastpath+0x16/0x1b

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  • Diving into OpenStack Network Architecture - Part 2 - Basic Use Cases

    - by Ronen Kofman
      rkofman Normal rkofman 4 138 2014-06-05T03:38:00Z 2014-06-05T05:04:00Z 3 2735 15596 Oracle Corporation 129 36 18295 12.00 Clean Clean false false false false EN-US X-NONE HE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi; mso-bidi-language:AR-SA;} In the previous post we reviewed several network components including Open vSwitch, Network Namespaces, Linux Bridges and veth pairs. In this post we will take three simple use cases and see how those basic components come together to create a complete SDN solution in OpenStack. With those three use cases we will review almost the entire network setup and see how all the pieces work together. The use cases we will use are: 1.       Create network – what happens when we create network and how can we create multiple isolated networks 2.       Launch a VM – once we have networks we can launch VMs and connect them to networks. 3.       DHCP request from a VM – OpenStack can automatically assign IP addresses to VMs. This is done through local DHCP service controlled by OpenStack Neutron. We will see how this service runs and how does a DHCP request and response look like. In this post we will show connectivity, we will see how packets get from point A to point B. We first focus on how a configured deployment looks like and only later we will discuss how and when the configuration is created. Personally I found it very valuable to see the actual interfaces and how they connect to each other through examples and hands on experiments. After the end game is clear and we know how the connectivity works, in a later post, we will take a step back and explain how Neutron configures the components to be able to provide such connectivity.  We are going to get pretty technical shortly and I recommend trying these examples on your own deployment or using the Oracle OpenStack Tech Preview. Understanding these three use cases thoroughly and how to look at them will be very helpful when trying to debug a deployment in case something does not work. Use case #1: Create Network Create network is a simple operation it can be performed from the GUI or command line. When we create a network in OpenStack the network is only available to the tenant who created it or it could be defined as “shared” and then it can be used by all tenants. A network can have multiple subnets but for this demonstration purpose and for simplicity we will assume that each network has exactly one subnet. Creating a network from the command line will look like this: # neutron net-create net1 Created a new network: +---------------------------+--------------------------------------+ | Field                     | Value                                | +---------------------------+--------------------------------------+ | admin_state_up            | True                                 | | id                        | 5f833617-6179-4797-b7c0-7d420d84040c | | name                      | net1                                 | | provider:network_type     | vlan                                 | | provider:physical_network | default                              | | provider:segmentation_id  | 1000                                 | | shared                    | False                                | | status                    | ACTIVE                               | | subnets                   |                                      | | tenant_id                 | 9796e5145ee546508939cd49ad59d51f     | +---------------------------+--------------------------------------+ Creating a subnet for this network will look like this: # neutron subnet-create net1 10.10.10.0/24 Created a new subnet: +------------------+------------------------------------------------+ | Field            | Value                                          | +------------------+------------------------------------------------+ | allocation_pools | {"start": "10.10.10.2", "end": "10.10.10.254"} | | cidr             | 10.10.10.0/24                                  | | dns_nameservers  |                                                | | enable_dhcp      | True                                           | | gateway_ip       | 10.10.10.1                                     | | host_routes      |                                                | | id               | 2d7a0a58-0674-439a-ad23-d6471aaae9bc           | | ip_version       | 4                                              | | name             |                                                | | network_id       | 5f833617-6179-4797-b7c0-7d420d84040c           | | tenant_id        | 9796e5145ee546508939cd49ad59d51f               | +------------------+------------------------------------------------+ We now have a network and a subnet, on the network topology view this looks like this: Now let’s dive in and see what happened under the hood. Looking at the control node we will discover that a new namespace was created: # ip netns list qdhcp-5f833617-6179-4797-b7c0-7d420d84040c   The name of the namespace is qdhcp-<network id> (see above), let’s look into the namespace and see what’s in it: # ip netns exec qdhcp-5f833617-6179-4797-b7c0-7d420d84040c ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00     inet 127.0.0.1/8 scope host lo     inet6 ::1/128 scope host        valid_lft forever preferred_lft forever 12: tap26c9b807-7c: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN     link/ether fa:16:3e:1d:5c:81 brd ff:ff:ff:ff:ff:ff     inet 10.10.10.3/24 brd 10.10.10.255 scope global tap26c9b807-7c     inet6 fe80::f816:3eff:fe1d:5c81/64 scope link        valid_lft forever preferred_lft forever   We see two interfaces in the namespace, one is the loopback and the other one is an interface called “tap26c9b807-7c”. This interface has the IP address of 10.10.10.3 and it will also serve dhcp requests in a way we will see later. Let’s trace the connectivity of the “tap26c9b807-7c” interface from the namespace.  First stop is OVS, we see that the interface connects to bridge  “br-int” on OVS: # ovs-vsctl show 8a069c7c-ea05-4375-93e2-b9fc9e4b3ca1     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2"                 type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"     Bridge br-ex         Port br-ex             Interface br-ex                 type: internal     Bridge br-int         Port "int-br-eth2"             Interface "int-br-eth2"         Port "tap26c9b807-7c"             tag: 1             Interface "tap26c9b807-7c"                 type: internal         Port br-int             Interface br-int                 type: internal     ovs_version: "1.11.0"   In the picture above we have a veth pair which has two ends called “int-br-eth2” and "phy-br-eth2", this veth pair is used to connect two bridge in OVS "br-eth2" and "br-int". In the previous post we explained how to check the veth connectivity using the ethtool command. It shows that the two are indeed a pair: # ethtool -S int-br-eth2 NIC statistics:      peer_ifindex: 10 . .   #ip link . . 10: phy-br-eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 . . Note that “phy-br-eth2” is connected to a bridge called "br-eth2" and one of this bridge's interfaces is the physical link eth2. This means that the network which we have just created has created a namespace which is connected to the physical interface eth2. eth2 is the “VM network” the physical interface where all the virtual machines connect to where all the VMs are connected. About network isolation: OpenStack supports creation of multiple isolated networks and can use several mechanisms to isolate the networks from one another. The isolation mechanism can be VLANs, VxLANs or GRE tunnels, this is configured as part of the initial setup in our deployment we use VLANs. When using VLAN tagging as an isolation mechanism a VLAN tag is allocated by Neutron from a pre-defined VLAN tags pool and assigned to the newly created network. By provisioning VLAN tags to the networks Neutron allows creation of multiple isolated networks on the same physical link.  The big difference between this and other platforms is that the user does not have to deal with allocating and managing VLANs to networks. The VLAN allocation and provisioning is handled by Neutron which keeps track of the VLAN tags, and responsible for allocating and reclaiming VLAN tags. In the example above net1 has the VLAN tag 1000, this means that whenever a VM is created and connected to this network the packets from that VM will have to be tagged with VLAN tag 1000 to go on this particular network. This is true for namespace as well, if we would like to connect a namespace to a particular network we have to make sure that the packets to and from the namespace are correctly tagged when they reach the VM network. In the example above we see that the namespace interface “tap26c9b807-7c” has vlan tag 1 assigned to it, if we examine OVS we see that it has flows which modify VLAN tag 1 to VLAN tag 1000 when a packet goes to the VM network on eth2 and vice versa. We can see this using the dump-flows command on OVS for packets going to the VM network we see the modification done on br-eth2: #  ovs-ofctl dump-flows br-eth2 NXST_FLOW reply (xid=0x4):  cookie=0x0, duration=18669.401s, table=0, n_packets=857, n_bytes=163350, idle_age=25, priority=4,in_port=2,dl_vlan=1 actions=mod_vlan_vid:1000,NORMAL  cookie=0x0, duration=165108.226s, table=0, n_packets=14, n_bytes=1000, idle_age=5343, hard_age=65534, priority=2,in_port=2 actions=drop  cookie=0x0, duration=165109.813s, table=0, n_packets=1671, n_bytes=213304, idle_age=25, hard_age=65534, priority=1 actions=NORMAL   For packets coming from the interface to the namespace we see the following modification: #  ovs-ofctl dump-flows br-int NXST_FLOW reply (xid=0x4):  cookie=0x0, duration=18690.876s, table=0, n_packets=1610, n_bytes=210752, idle_age=1, priority=3,in_port=1,dl_vlan=1000 actions=mod_vlan_vid:1,NORMAL  cookie=0x0, duration=165130.01s, table=0, n_packets=75, n_bytes=3686, idle_age=4212, hard_age=65534, priority=2,in_port=1 actions=drop  cookie=0x0, duration=165131.96s, table=0, n_packets=863, n_bytes=160727, idle_age=1, hard_age=65534, priority=1 actions=NORMAL   To summarize we can see that when a user creates a network Neutron creates a namespace and this namespace is connected through OVS to the “VM network”. OVS also takes care of tagging the packets from the namespace to the VM network with the correct VLAN tag and knows to modify the VLAN for packets coming from VM network to the namespace. Now let’s see what happens when a VM is launched and how it is connected to the “VM network”. Use case #2: Launch a VM Launching a VM can be done from Horizon or from the command line this is how we do it from Horizon: Attach the network: And Launch Once the virtual machine is up and running we can see the associated IP using the nova list command : # nova list +--------------------------------------+--------------+--------+------------+-------------+-----------------+ | ID                                   | Name         | Status | Task State | Power State | Networks        | +--------------------------------------+--------------+--------+------------+-------------+-----------------+ | 3707ac87-4f5d-4349-b7ed-3a673f55e5e1 | Oracle Linux | ACTIVE | None       | Running     | net1=10.10.10.2 | +--------------------------------------+--------------+--------+------------+-------------+-----------------+ The nova list command shows us that the VM is running and that the IP 10.10.10.2 is assigned to this VM. Let’s trace the connectivity from the VM to VM network on eth2 starting with the VM definition file. The configuration files of the VM including the virtual disk(s), in case of ephemeral storage, are stored on the compute node at/var/lib/nova/instances/<instance-id>/. Looking into the VM definition file ,libvirt.xml,  we see that the VM is connected to an interface called “tap53903a95-82” which is connected to a Linux bridge called “qbr53903a95-82”: <interface type="bridge">       <mac address="fa:16:3e:fe:c7:87"/>       <source bridge="qbr53903a95-82"/>       <target dev="tap53903a95-82"/>     </interface>   Looking at the bridge using the brctl show command we see this: # brctl show bridge name     bridge id               STP enabled     interfaces qbr53903a95-82          8000.7e7f3282b836       no              qvb53903a95-82                                                         tap53903a95-82    The bridge has two interfaces, one connected to the VM (“tap53903a95-82 “) and another one ( “qvb53903a95-82”) connected to “br-int” bridge on OVS: # ovs-vsctl show 83c42f80-77e9-46c8-8560-7697d76de51c     Bridge "br-eth2"         Port "br-eth2"             Interface "br-eth2"                 type: internal         Port "eth2"             Interface "eth2"         Port "phy-br-eth2"             Interface "phy-br-eth2"     Bridge br-int         Port br-int             Interface br-int                 type: internal         Port "int-br-eth2"             Interface "int-br-eth2"         Port "qvo53903a95-82"             tag: 3             Interface "qvo53903a95-82"     ovs_version: "1.11.0"   As we showed earlier “br-int” is connected to “br-eth2” on OVS using the veth pair int-br-eth2,phy-br-eth2 and br-eth2 is connected to the physical interface eth2. The whole flow end to end looks like this: VM è tap53903a95-82 (virtual interface)è qbr53903a95-82 (Linux bridge) è qvb53903a95-82 (interface connected from Linux bridge to OVS bridge br-int) è int-br-eth2 (veth one end) è phy-br-eth2 (veth the other end) è eth2 physical interface. The purpose of the Linux Bridge connecting to the VM is to allow security group enforcement with iptables. Security groups are enforced at the edge point which are the interface of the VM, since iptables nnot be applied to OVS bridges we use Linux bridge to apply them. In the future we hope to see this Linux Bridge going away rules.  VLAN tags: As we discussed in the first use case net1 is using VLAN tag 1000, looking at OVS above we see that qvo41f1ebcf-7c is tagged with VLAN tag 3. The modification from VLAN tag 3 to 1000 as we go to the physical network is done by OVS  as part of the packet flow of br-eth2 in the same way we showed before. To summarize, when a VM is launched it is connected to the VM network through a chain of elements as described here. During the packet from VM to the network and back the VLAN tag is modified. Use case #3: Serving a DHCP request coming from the virtual machine In the previous use cases we have shown that both the namespace called dhcp-<some id> and the VM end up connecting to the physical interface eth2  on their respective nodes, both will tag their packets with VLAN tag 1000.We saw that the namespace has an interface with IP of 10.10.10.3. Since the VM and the namespace are connected to each other and have interfaces on the same subnet they can ping each other, in this picture we see a ping from the VM which was assigned 10.10.10.2 to the namespace: The fact that they are connected and can ping each other can become very handy when something doesn’t work right and we need to isolate the problem. In such case knowing that we should be able to ping from the VM to the namespace and back can be used to trace the disconnect using tcpdump or other monitoring tools. To serve DHCP requests coming from VMs on the network Neutron uses a Linux tool called “dnsmasq”,this is a lightweight DNS and DHCP service you can read more about it here. If we look at the dnsmasq on the control node with the ps command we see this: dnsmasq --no-hosts --no-resolv --strict-order --bind-interfaces --interface=tap26c9b807-7c --except-interface=lo --pid-file=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/pid --dhcp-hostsfile=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/host --dhcp-optsfile=/var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/opts --leasefile-ro --dhcp-range=tag0,10.10.10.0,static,120s --dhcp-lease-max=256 --conf-file= --domain=openstacklocal The service connects to the tap interface in the namespace (“--interface=tap26c9b807-7c”), If we look at the hosts file we see this: # cat  /var/lib/neutron/dhcp/5f833617-6179-4797-b7c0-7d420d84040c/host fa:16:3e:fe:c7:87,host-10-10-10-2.openstacklocal,10.10.10.2   If you look at the console output above you can see the MAC address fa:16:3e:fe:c7:87 which is the VM MAC. This MAC address is mapped to IP 10.10.10.2 and so when a DHCP request comes with this MAC dnsmasq will return the 10.10.10.2.If we look into the namespace at the time we initiate a DHCP request from the VM (this can be done by simply restarting the network service in the VM) we see the following: # ip netns exec qdhcp-5f833617-6179-4797-b7c0-7d420d84040c tcpdump -n 19:27:12.191280 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:fe:c7:87, length 310 19:27:12.191666 IP 10.10.10.3.bootps > 10.10.10.2.bootpc: BOOTP/DHCP, Reply, length 325   To summarize, the DHCP service is handled by dnsmasq which is configured by Neutron to listen to the interface in the DHCP namespace. Neutron also configures dnsmasq with the combination of MAC and IP so when a DHCP request comes along it will receive the assigned IP. Summary In this post we relied on the components described in the previous post and saw how network connectivity is achieved using three simple use cases. These use cases gave a good view of the entire network stack and helped understand how an end to end connection is being made between a VM on a compute node and the DHCP namespace on the control node. One conclusion we can draw from what we saw here is that if we launch a VM and it is able to perform a DHCP request and receive a correct IP then there is reason to believe that the network is working as expected. We saw that a packet has to travel through a long list of components before reaching its destination and if it has done so successfully this means that many components are functioning properly. In the next post we will look at some more sophisticated services Neutron supports and see how they work. We will see that while there are some more components involved for the most part the concepts are the same. @RonenKofman

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  • Disable .htaccess from apache allowoverride none, still reads .htaccess files

    - by John Magnolia
    I have moved all of our .htaccess config into <Directory> blocks and set AllowOverride None in the default and default-ssl. Although after restarting apache it is still reading the .htaccess files. How can I completely turn off reading these files? Update of all files with "AllowOverride" /etc/apache2/mods-available/userdir.conf <IfModule mod_userdir.c> UserDir public_html UserDir disabled root <Directory /home/*/public_html> AllowOverride FileInfo AuthConfig Limit Indexes Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec <Limit GET POST OPTIONS> Order allow,deny Allow from all </Limit> <LimitExcept GET POST OPTIONS> Order deny,allow Deny from all </LimitExcept> </Directory> </IfModule> /etc/apache2/mods-available/alias.conf <IfModule alias_module> # # Aliases: Add here as many aliases as you need (with no limit). The format is # Alias fakename realname # # Note that if you include a trailing / on fakename then the server will # require it to be present in the URL. So "/icons" isn't aliased in this # example, only "/icons/". If the fakename is slash-terminated, then the # realname must also be slash terminated, and if the fakename omits the # trailing slash, the realname must also omit it. # # We include the /icons/ alias for FancyIndexed directory listings. If # you do not use FancyIndexing, you may comment this out. # Alias /icons/ "/usr/share/apache2/icons/" <Directory "/usr/share/apache2/icons"> Options Indexes MultiViews AllowOverride None Order allow,deny Allow from all </Directory> </IfModule> /etc/apache2/httpd.conf # # Directives to allow use of AWStats as a CGI # Alias /awstatsclasses "/usr/share/doc/awstats/examples/wwwroot/classes/" Alias /awstatscss "/usr/share/doc/awstats/examples/wwwroot/css/" Alias /awstatsicons "/usr/share/doc/awstats/examples/wwwroot/icon/" ScriptAlias /awstats/ "/usr/share/doc/awstats/examples/wwwroot/cgi-bin/" # # This is to permit URL access to scripts/files in AWStats directory. # <Directory "/usr/share/doc/awstats/examples/wwwroot"> Options None AllowOverride None Order allow,deny Allow from all </Directory> Alias /awstats-icon/ /usr/share/awstats/icon/ <Directory /usr/share/awstats/icon> Options None AllowOverride None Order allow,deny Allow from all </Directory> /etc/apache2/sites-available/default-ssl <IfModule mod_ssl.c> <VirtualHost _default_:443> ServerAdmin webmaster@localhost DocumentRoot /var/www <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/> Options Indexes FollowSymLinks MultiViews AllowOverride None </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/ssl_access.log combined # SSL Engine Switch: # Enable/Disable SSL for this virtual host. SSLEngine on # A self-signed (snakeoil) certificate can be created by installing # the ssl-cert package. See # /usr/share/doc/apache2.2-common/README.Debian.gz for more info. # If both key and certificate are stored in the same file, only the # SSLCertificateFile directive is needed. SSLCertificateFile /etc/ssl/certs/ssl-cert-snakeoil.pem SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key # Server Certificate Chain: # Point SSLCertificateChainFile at a file containing the # concatenation of PEM encoded CA certificates which form the # certificate chain for the server certificate. Alternatively # the referenced file can be the same as SSLCertificateFile # when the CA certificates are directly appended to the server # certificate for convinience. #SSLCertificateChainFile /etc/apache2/ssl.crt/server-ca.crt # Certificate Authority (CA): # Set the CA certificate verification path where to find CA # certificates for client authentication or alternatively one # huge file containing all of them (file must be PEM encoded) # Note: Inside SSLCACertificatePath you need hash symlinks # to point to the certificate files. Use the provided # Makefile to update the hash symlinks after changes. #SSLCACertificatePath /etc/ssl/certs/ #SSLCACertificateFile /etc/apache2/ssl.crt/ca-bundle.crt # Certificate Revocation Lists (CRL): # Set the CA revocation path where to find CA CRLs for client # authentication or alternatively one huge file containing all # of them (file must be PEM encoded) # Note: Inside SSLCARevocationPath you need hash symlinks # to point to the certificate files. Use the provided # Makefile to update the hash symlinks after changes. #SSLCARevocationPath /etc/apache2/ssl.crl/ #SSLCARevocationFile /etc/apache2/ssl.crl/ca-bundle.crl # Client Authentication (Type): # Client certificate verification type and depth. Types are # none, optional, require and optional_no_ca. Depth is a # number which specifies how deeply to verify the certificate # issuer chain before deciding the certificate is not valid. #SSLVerifyClient require #SSLVerifyDepth 10 # Access Control: # With SSLRequire you can do per-directory access control based # on arbitrary complex boolean expressions containing server # variable checks and other lookup directives. The syntax is a # mixture between C and Perl. See the mod_ssl documentation # for more details. #<Location /> #SSLRequire ( %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \ # and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \ # and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \ # and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \ # and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20 ) \ # or %{REMOTE_ADDR} =~ m/^192\.76\.162\.[0-9]+$/ #</Location> # SSL Engine Options: # Set various options for the SSL engine. # o FakeBasicAuth: # Translate the client X.509 into a Basic Authorisation. This means that # the standard Auth/DBMAuth methods can be used for access control. The # user name is the `one line' version of the client's X.509 certificate. # Note that no password is obtained from the user. Every entry in the user # file needs this password: `xxj31ZMTZzkVA'. # o ExportCertData: # This exports two additional environment variables: SSL_CLIENT_CERT and # SSL_SERVER_CERT. These contain the PEM-encoded certificates of the # server (always existing) and the client (only existing when client # authentication is used). This can be used to import the certificates # into CGI scripts. # o StdEnvVars: # This exports the standard SSL/TLS related `SSL_*' environment variables. # Per default this exportation is switched off for performance reasons, # because the extraction step is an expensive operation and is usually # useless for serving static content. So one usually enables the # exportation for CGI and SSI requests only. # o StrictRequire: # This denies access when "SSLRequireSSL" or "SSLRequire" applied even # under a "Satisfy any" situation, i.e. when it applies access is denied # and no other module can change it. # o OptRenegotiate: # This enables optimized SSL connection renegotiation handling when SSL # directives are used in per-directory context. #SSLOptions +FakeBasicAuth +ExportCertData +StrictRequire <FilesMatch "\.(cgi|shtml|phtml|php)$"> SSLOptions +StdEnvVars </FilesMatch> <Directory /usr/lib/cgi-bin> SSLOptions +StdEnvVars </Directory> # SSL Protocol Adjustments: # The safe and default but still SSL/TLS standard compliant shutdown # approach is that mod_ssl sends the close notify alert but doesn't wait for # the close notify alert from client. When you need a different shutdown # approach you can use one of the following variables: # o ssl-unclean-shutdown: # This forces an unclean shutdown when the connection is closed, i.e. no # SSL close notify alert is send or allowed to received. This violates # the SSL/TLS standard but is needed for some brain-dead browsers. Use # this when you receive I/O errors because of the standard approach where # mod_ssl sends the close notify alert. # o ssl-accurate-shutdown: # This forces an accurate shutdown when the connection is closed, i.e. a # SSL close notify alert is send and mod_ssl waits for the close notify # alert of the client. This is 100% SSL/TLS standard compliant, but in # practice often causes hanging connections with brain-dead browsers. Use # this only for browsers where you know that their SSL implementation # works correctly. # Notice: Most problems of broken clients are also related to the HTTP # keep-alive facility, so you usually additionally want to disable # keep-alive for those clients, too. Use variable "nokeepalive" for this. # Similarly, one has to force some clients to use HTTP/1.0 to workaround # their broken HTTP/1.1 implementation. Use variables "downgrade-1.0" and # "force-response-1.0" for this. BrowserMatch "MSIE [2-6]" \ nokeepalive ssl-unclean-shutdown \ downgrade-1.0 force-response-1.0 # MSIE 7 and newer should be able to use keepalive BrowserMatch "MSIE [17-9]" ssl-unclean-shutdown </VirtualHost> </IfModule> /etc/apache2/sites-available/default <VirtualHost *:80> ServerAdmin webmaster@localhost DocumentRoot /var/www <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/> Options -Indexes FollowSymLinks MultiViews AllowOverride None Order allow,deny allow from all </Directory> ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/ <Directory "/usr/lib/cgi-bin"> AllowOverride None Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch Order allow,deny Allow from all </Directory> Alias /delboy /usr/share/phpmyadmin <Directory /usr/share/phpmyadmin> # Restrict phpmyadmin access Order Deny,Allow Allow from all </Directory> ErrorLog ${APACHE_LOG_DIR}/error.log # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. LogLevel warn CustomLog ${APACHE_LOG_DIR}/access.log combined Alias /doc/ "/usr/share/doc/" <Directory "/usr/share/doc/"> Options Indexes MultiViews FollowSymLinks AllowOverride None Order deny,allow Deny from all Allow from 127.0.0.0/255.0.0.0 ::1/128 </Directory> </VirtualHost> /etc/apache2/conf.d/security # # Disable access to the entire file system except for the directories that # are explicitly allowed later. # # This currently breaks the configurations that come with some web application # Debian packages. # #<Directory /> # AllowOverride None # Order Deny,Allow # Deny from all #</Directory> # Changing the following options will not really affect the security of the # server, but might make attacks slightly more difficult in some cases. # # ServerTokens # This directive configures what you return as the Server HTTP response # Header. The default is 'Full' which sends information about the OS-Type # and compiled in modules. # Set to one of: Full | OS | Minimal | Minor | Major | Prod # where Full conveys the most information, and Prod the least. # #ServerTokens Minimal ServerTokens OS #ServerTokens Full # # Optionally add a line containing the server version and virtual host # name to server-generated pages (internal error documents, FTP directory # listings, mod_status and mod_info output etc., but not CGI generated # documents or custom error documents). # Set to "EMail" to also include a mailto: link to the ServerAdmin. # Set to one of: On | Off | EMail # #ServerSignature Off ServerSignature On # # Allow TRACE method # # Set to "extended" to also reflect the request body (only for testing and # diagnostic purposes). # # Set to one of: On | Off | extended # TraceEnable Off #TraceEnable On /etc/apache2/apache2.conf # # Based upon the NCSA server configuration files originally by Rob McCool. # # This is the main Apache server configuration file. It contains the # configuration directives that give the server its instructions. # See http://httpd.apache.org/docs/2.2/ for detailed information about # the directives. # # Do NOT simply read the instructions in here without understanding # what they do. They're here only as hints or reminders. If you are unsure # consult the online docs. You have been warned. # # The configuration directives are grouped into three basic sections: # 1. Directives that control the operation of the Apache server process as a # whole (the 'global environment'). # 2. Directives that define the parameters of the 'main' or 'default' server, # which responds to requests that aren't handled by a virtual host. # These directives also provide default values for the settings # of all virtual hosts. # 3. Settings for virtual hosts, which allow Web requests to be sent to # different IP addresses or hostnames and have them handled by the # same Apache server process. # # Configuration and logfile names: If the filenames you specify for many # of the server's control files begin with "/" (or "drive:/" for Win32), the # server will use that explicit path. If the filenames do *not* begin # with "/", the value of ServerRoot is prepended -- so "foo.log" # with ServerRoot set to "/etc/apache2" will be interpreted by the # server as "/etc/apache2/foo.log". # ### Section 1: Global Environment # # The directives in this section affect the overall operation of Apache, # such as the number of concurrent requests it can handle or where it # can find its configuration files. # # # ServerRoot: The top of the directory tree under which the server's # configuration, error, and log files are kept. # # NOTE! If you intend to place this on an NFS (or otherwise network) # mounted filesystem then please read the LockFile documentation (available # at <URL:http://httpd.apache.org/docs/2.2/mod/mpm_common.html#lockfile>); # you will save yourself a lot of trouble. # # Do NOT add a slash at the end of the directory path. # #ServerRoot "/etc/apache2" # # The accept serialization lock file MUST BE STORED ON A LOCAL DISK. # LockFile ${APACHE_LOCK_DIR}/accept.lock # # PidFile: The file in which the server should record its process # identification number when it starts. # This needs to be set in /etc/apache2/envvars # PidFile ${APACHE_PID_FILE} # # Timeout: The number of seconds before receives and sends time out. # Timeout 300 # # KeepAlive: Whether or not to allow persistent connections (more than # one request per connection). Set to "Off" to deactivate. # KeepAlive On # # MaxKeepAliveRequests: The maximum number of requests to allow # during a persistent connection. Set to 0 to allow an unlimited amount. # We recommend you leave this number high, for maximum performance. # MaxKeepAliveRequests 100 # # KeepAliveTimeout: Number of seconds to wait for the next request from the # same client on the same connection. # KeepAliveTimeout 4 ## ## Server-Pool Size Regulation (MPM specific) ## # prefork MPM # StartServers: number of server processes to start # MinSpareServers: minimum number of server processes which are kept spare # MaxSpareServers: maximum number of server processes which are kept spare # MaxClients: maximum number of server processes allowed to start # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_prefork_module> StartServers 5 MinSpareServers 5 MaxSpareServers 10 MaxClients 150 MaxRequestsPerChild 500 </IfModule> # worker MPM # StartServers: initial number of server processes to start # MaxClients: maximum number of simultaneous client connections # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadLimit: ThreadsPerChild can be changed to this maximum value during a # graceful restart. ThreadLimit can only be changed by stopping # and starting Apache. # ThreadsPerChild: constant number of worker threads in each server process # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_worker_module> StartServers 2 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 150 MaxRequestsPerChild 0 </IfModule> # event MPM # StartServers: initial number of server processes to start # MaxClients: maximum number of simultaneous client connections # MinSpareThreads: minimum number of worker threads which are kept spare # MaxSpareThreads: maximum number of worker threads which are kept spare # ThreadsPerChild: constant number of worker threads in each server process # MaxRequestsPerChild: maximum number of requests a server process serves <IfModule mpm_event_module> StartServers 2 MaxClients 150 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxRequestsPerChild 0 </IfModule> # These need to be set in /etc/apache2/envvars User ${APACHE_RUN_USER} Group ${APACHE_RUN_GROUP} # # AccessFileName: The name of the file to look for in each directory # for additional configuration directives. See also the AllowOverride # directive. # AccessFileName .htaccess # # The following lines prevent .htaccess and .htpasswd files from being # viewed by Web clients. # <Files ~ "^\.ht"> Order allow,deny Deny from all Satisfy all </Files> # # DefaultType is the default MIME type the server will use for a document # if it cannot otherwise determine one, such as from filename extensions. # If your server contains mostly text or HTML documents, "text/plain" is # a good value. If most of your content is binary, such as applications # or images, you may want to use "application/octet-stream" instead to # keep browsers from trying to display binary files as though they are # text. # DefaultType text/plain # # HostnameLookups: Log the names of clients or just their IP addresses # e.g., www.apache.org (on) or 204.62.129.132 (off). # The default is off because it'd be overall better for the net if people # had to knowingly turn this feature on, since enabling it means that # each client request will result in AT LEAST one lookup request to the # nameserver. # HostnameLookups Off # ErrorLog: The location of the error log file. # If you do not specify an ErrorLog directive within a <VirtualHost> # container, error messages relating to that virtual host will be # logged here. If you *do* define an error logfile for a <VirtualHost> # container, that host's errors will be logged there and not here. # ErrorLog ${APACHE_LOG_DIR}/error.log # # LogLevel: Control the number of messages logged to the error_log. # Possible values include: debug, info, notice, warn, error, crit, # alert, emerg. # LogLevel warn # Include module configuration: Include mods-enabled/*.load Include mods-enabled/*.conf # Include all the user configurations: Include httpd.conf # Include ports listing Include ports.conf # # The following directives define some format nicknames for use with # a CustomLog directive (see below). # If you are behind a reverse proxy, you might want to change %h into %{X-Forwarded-For}i # LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %O" common LogFormat "%{Referer}i -> %U" referer LogFormat "%{User-agent}i" agent # Include of directories ignores editors' and dpkg's backup files, # see README.Debian for details. # Include generic snippets of statements Include conf.d/ # Include the virtual host configurations: Include sites-enabled/

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  • The Incremental Architect&rsquo;s Napkin - #5 - Design functions for extensibility and readability

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/08/24/the-incremental-architectrsquos-napkin---5---design-functions-for.aspx The functionality of programs is entered via Entry Points. So what we´re talking about when designing software is a bunch of functions handling the requests represented by and flowing in through those Entry Points. Designing software thus consists of at least three phases: Analyzing the requirements to find the Entry Points and their signatures Designing the functionality to be executed when those Entry Points get triggered Implementing the functionality according to the design aka coding I presume, you´re familiar with phase 1 in some way. And I guess you´re proficient in implementing functionality in some programming language. But in my experience developers in general are not experienced in going through an explicit phase 2. “Designing functionality? What´s that supposed to mean?” you might already have thought. Here´s my definition: To design functionality (or functional design for short) means thinking about… well, functions. You find a solution for what´s supposed to happen when an Entry Point gets triggered in terms of functions. A conceptual solution that is, because those functions only exist in your head (or on paper) during this phase. But you may have guess that, because it´s “design” not “coding”. And here is, what functional design is not: It´s not about logic. Logic is expressions (e.g. +, -, && etc.) and control statements (e.g. if, switch, for, while etc.). Also I consider calling external APIs as logic. It´s equally basic. It´s what code needs to do in order to deliver some functionality or quality. Logic is what´s doing that needs to be done by software. Transformations are either done through expressions or API-calls. And then there is alternative control flow depending on the result of some expression. Basically it´s just jumps in Assembler, sometimes to go forward (if, switch), sometimes to go backward (for, while, do). But calling your own function is not logic. It´s not necessary to produce any outcome. Functionality is not enhanced by adding functions (subroutine calls) to your code. Nor is quality increased by adding functions. No performance gain, no higher scalability etc. through functions. Functions are not relevant to functionality. Strange, isn´t it. What they are important for is security of investment. By introducing functions into our code we can become more productive (re-use) and can increase evolvability (higher unterstandability, easier to keep code consistent). That´s no small feat, however. Evolvable code can hardly be overestimated. That´s why to me functional design is so important. It´s at the core of software development. To sum this up: Functional design is on a level of abstraction above (!) logical design or algorithmic design. Functional design is only done until you get to a point where each function is so simple you are very confident you can easily code it. Functional design an logical design (which mostly is coding, but can also be done using pseudo code or flow charts) are complementary. Software needs both. If you start coding right away you end up in a tangled mess very quickly. Then you need back out through refactoring. Functional design on the other hand is bloodless without actual code. It´s just a theory with no experiments to prove it. But how to do functional design? An example of functional design Let´s assume a program to de-duplicate strings. The user enters a number of strings separated by commas, e.g. a, b, a, c, d, b, e, c, a. And the program is supposed to clear this list of all doubles, e.g. a, b, c, d, e. There is only one Entry Point to this program: the user triggers the de-duplication by starting the program with the string list on the command line C:\>deduplicate "a, b, a, c, d, b, e, c, a" a, b, c, d, e …or by clicking on a GUI button. This leads to the Entry Point function to get called. It´s the program´s main function in case of the batch version or a button click event handler in the GUI version. That´s the physical Entry Point so to speak. It´s inevitable. What then happens is a three step process: Transform the input data from the user into a request. Call the request handler. Transform the output of the request handler into a tangible result for the user. Or to phrase it a bit more generally: Accept input. Transform input into output. Present output. This does not mean any of these steps requires a lot of effort. Maybe it´s just one line of code to accomplish it. Nevertheless it´s a distinct step in doing the processing behind an Entry Point. Call it an aspect or a responsibility - and you will realize it most likely deserves a function of its own to satisfy the Single Responsibility Principle (SRP). Interestingly the above list of steps is already functional design. There is no logic, but nevertheless the solution is described - albeit on a higher level of abstraction than you might have done yourself. But it´s still on a meta-level. The application to the domain at hand is easy, though: Accept string list from command line De-duplicate Present de-duplicated strings on standard output And this concrete list of processing steps can easily be transformed into code:static void Main(string[] args) { var input = Accept_string_list(args); var output = Deduplicate(input); Present_deduplicated_string_list(output); } Instead of a big problem there are three much smaller problems now. If you think each of those is trivial to implement, then go for it. You can stop the functional design at this point. But maybe, just maybe, you´re not so sure how to go about with the de-duplication for example. Then just implement what´s easy right now, e.g.private static string Accept_string_list(string[] args) { return args[0]; } private static void Present_deduplicated_string_list( string[] output) { var line = string.Join(", ", output); Console.WriteLine(line); } Accept_string_list() contains logic in the form of an API-call. Present_deduplicated_string_list() contains logic in the form of an expression and an API-call. And then repeat the functional design for the remaining processing step. What´s left is the domain logic: de-duplicating a list of strings. How should that be done? Without any logic at our disposal during functional design you´re left with just functions. So which functions could make up the de-duplication? Here´s a suggestion: De-duplicate Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Processing step 2 obviously was the core of the solution. That´s where real creativity was needed. That´s the core of the domain. But now after this refinement the implementation of each step is easy again:private static string[] Parse_string_list(string input) { return input.Split(',') .Select(s => s.Trim()) .ToArray(); } private static Dictionary<string,object> Compile_unique_strings(string[] strings) { return strings.Aggregate( new Dictionary<string, object>(), (agg, s) => { agg[s] = null; return agg; }); } private static string[] Serialize_unique_strings( Dictionary<string,object> dict) { return dict.Keys.ToArray(); } With these three additional functions Main() now looks like this:static void Main(string[] args) { var input = Accept_string_list(args); var strings = Parse_string_list(input); var dict = Compile_unique_strings(strings); var output = Serialize_unique_strings(dict); Present_deduplicated_string_list(output); } I think that´s very understandable code: just read it from top to bottom and you know how the solution to the problem works. It´s a mirror image of the initial design: Accept string list from command line Parse the input string into a true list of strings. Register each string in a dictionary/map/set. That way duplicates get cast away. Transform the data structure into a list of unique strings. Present de-duplicated strings on standard output You can even re-generate the design by just looking at the code. Code and functional design thus are always in sync - if you follow some simple rules. But about that later. And as a bonus: all the functions making up the process are small - which means easy to understand, too. So much for an initial concrete example. Now it´s time for some theory. Because there is method to this madness ;-) The above has only scratched the surface. Introducing Flow Design Functional design starts with a given function, the Entry Point. Its goal is to describe the behavior of the program when the Entry Point is triggered using a process, not an algorithm. An algorithm consists of logic, a process on the other hand consists just of steps or stages. Each processing step transforms input into output or a side effect. Also it might access resources, e.g. a printer, a database, or just memory. Processing steps thus can rely on state of some sort. This is different from Functional Programming, where functions are supposed to not be stateful and not cause side effects.[1] In its simplest form a process can be written as a bullet point list of steps, e.g. Get data from user Output result to user Transform data Parse data Map result for output Such a compilation of steps - possibly on different levels of abstraction - often is the first artifact of functional design. It can be generated by a team in an initial design brainstorming. Next comes ordering the steps. What should happen first, what next etc.? Get data from user Parse data Transform data Map result for output Output result to user That´s great for a start into functional design. It´s better than starting to code right away on a given function using TDD. Please get me right: TDD is a valuable practice. But it can be unnecessarily hard if the scope of a functionn is too large. But how do you know beforehand without investing some thinking? And how to do this thinking in a systematic fashion? My recommendation: For any given function you´re supposed to implement first do a functional design. Then, once you´re confident you know the processing steps - which are pretty small - refine and code them using TDD. You´ll see that´s much, much easier - and leads to cleaner code right away. For more information on this approach I call “Informed TDD” read my book of the same title. Thinking before coding is smart. And writing down the solution as a bunch of functions possibly is the simplest thing you can do, I´d say. It´s more according to the KISS (Keep It Simple, Stupid) principle than returning constants or other trivial stuff TDD development often is started with. So far so good. A simple ordered list of processing steps will do to start with functional design. As shown in the above example such steps can easily be translated into functions. Moving from design to coding thus is simple. However, such a list does not scale. Processing is not always that simple to be captured in a list. And then the list is just text. Again. Like code. That means the design is lacking visuality. Textual representations need more parsing by your brain than visual representations. Plus they are limited in their “dimensionality”: text just has one dimension, it´s sequential. Alternatives and parallelism are hard to encode in text. In addition the functional design using numbered lists lacks data. It´s not visible what´s the input, output, and state of the processing steps. That´s why functional design should be done using a lightweight visual notation. No tool is necessary to draw such designs. Use pen and paper; a flipchart, a whiteboard, or even a napkin is sufficient. Visualizing processes The building block of the functional design notation is a functional unit. I mostly draw it like this: Something is done, it´s clear what goes in, it´s clear what comes out, and it´s clear what the processing step requires in terms of state or hardware. Whenever input flows into a functional unit it gets processed and output is produced and/or a side effect occurs. Flowing data is the driver of something happening. That´s why I call this approach to functional design Flow Design. It´s about data flow instead of control flow. Control flow like in algorithms is of no concern to functional design. Thinking about control flow simply is too low level. Once you start with control flow you easily get bogged down by tons of details. That´s what you want to avoid during design. Design is supposed to be quick, broad brush, abstract. It should give overview. But what about all the details? As Robert C. Martin rightly said: “Programming is abot detail”. Detail is a matter of code. Once you start coding the processing steps you designed you can worry about all the detail you want. Functional design does not eliminate all the nitty gritty. It just postpones tackling them. To me that´s also an example of the SRP. Function design has the responsibility to come up with a solution to a problem posed by a single function (Entry Point). And later coding has the responsibility to implement the solution down to the last detail (i.e. statement, API-call). TDD unfortunately mixes both responsibilities. It´s just coding - and thereby trying to find detailed implementations (green phase) plus getting the design right (refactoring). To me that´s one reason why TDD has failed to deliver on its promise for many developers. Using functional units as building blocks of functional design processes can be depicted very easily. Here´s the initial process for the example problem: For each processing step draw a functional unit and label it. Choose a verb or an “action phrase” as a label, not a noun. Functional design is about activities, not state or structure. Then make the output of an upstream step the input of a downstream step. Finally think about the data that should flow between the functional units. Write the data above the arrows connecting the functional units in the direction of the data flow. Enclose the data description in brackets. That way you can clearly see if all flows have already been specified. Empty brackets mean “no data is flowing”, but nevertheless a signal is sent. A name like “list” or “strings” in brackets describes the data content. Use lower case labels for that purpose. A name starting with an upper case letter like “String” or “Customer” on the other hand signifies a data type. If you like, you also can combine descriptions with data types by separating them with a colon, e.g. (list:string) or (strings:string[]). But these are just suggestions from my practice with Flow Design. You can do it differently, if you like. Just be sure to be consistent. Flows wired-up in this manner I call one-dimensional (1D). Each functional unit just has one input and/or one output. A functional unit without an output is possible. It´s like a black hole sucking up input without producing any output. Instead it produces side effects. A functional unit without an input, though, does make much sense. When should it start to work? What´s the trigger? That´s why in the above process even the first processing step has an input. If you like, view such 1D-flows as pipelines. Data is flowing through them from left to right. But as you can see, it´s not always the same data. It get´s transformed along its passage: (args) becomes a (list) which is turned into (strings). The Principle of Mutual Oblivion A very characteristic trait of flows put together from function units is: no functional units knows another one. They are all completely independent of each other. Functional units don´t know where their input is coming from (or even when it´s gonna arrive). They just specify a range of values they can process. And they promise a certain behavior upon input arriving. Also they don´t know where their output is going. They just produce it in their own time independent of other functional units. That means at least conceptually all functional units work in parallel. Functional units don´t know their “deployment context”. They now nothing about the overall flow they are place in. They are just consuming input from some upstream, and producing output for some downstream. That makes functional units very easy to test. At least as long as they don´t depend on state or resources. I call this the Principle of Mutual Oblivion (PoMO). Functional units are oblivious of others as well as an overall context/purpose. They are just parts of a whole focused on a single responsibility. How the whole is built, how a larger goal is achieved, is of no concern to the single functional units. By building software in such a manner, functional design interestingly follows nature. Nature´s building blocks for organisms also follow the PoMO. The cells forming your body do not know each other. Take a nerve cell “controlling” a muscle cell for example:[2] The nerve cell does not know anything about muscle cells, let alone the specific muscel cell it is “attached to”. Likewise the muscle cell does not know anything about nerve cells, let a lone a specific nerve cell “attached to” it. Saying “the nerve cell is controlling the muscle cell” thus only makes sense when viewing both from the outside. “Control” is a concept of the whole, not of its parts. Control is created by wiring-up parts in a certain way. Both cells are mutually oblivious. Both just follow a contract. One produces Acetylcholine (ACh) as output, the other consumes ACh as input. Where the ACh is going, where it´s coming from neither cell cares about. Million years of evolution have led to this kind of division of labor. And million years of evolution have produced organism designs (DNA) which lead to the production of these different cell types (and many others) and also to their co-location. The result: the overall behavior of an organism. How and why this happened in nature is a mystery. For our software, though, it´s clear: functional and quality requirements needs to be fulfilled. So we as developers have to become “intelligent designers” of “software cells” which we put together to form a “software organism” which responds in satisfying ways to triggers from it´s environment. My bet is: If nature gets complex organisms working by following the PoMO, who are we to not apply this recipe for success to our much simpler “machines”? So my rule is: Wherever there is functionality to be delivered, because there is a clear Entry Point into software, design the functionality like nature would do it. Build it from mutually oblivious functional units. That´s what Flow Design is about. In that way it´s even universal, I´d say. Its notation can also be applied to biology: Never mind labeling the functional units with nouns. That´s ok in Flow Design. You´ll do that occassionally for functional units on a higher level of abstraction or when their purpose is close to hardware. Getting a cockroach to roam your bedroom takes 1,000,000 nerve cells (neurons). Getting the de-duplication program to do its job just takes 5 “software cells” (functional units). Both, though, follow the same basic principle. Translating functional units into code Moving from functional design to code is no rocket science. In fact it´s straightforward. There are two simple rules: Translate an input port to a function. Translate an output port either to a return statement in that function or to a function pointer visible to that function. The simplest translation of a functional unit is a function. That´s what you saw in the above example. Functions are mutually oblivious. That why Functional Programming likes them so much. It makes them composable. Which is the reason, nature works according to the PoMO. Let´s be clear about one thing: There is no dependency injection in nature. For all of an organism´s complexity no DI container is used. Behavior is the result of smooth cooperation between mutually oblivious building blocks. Functions will often be the adequate translation for the functional units in your designs. But not always. Take for example the case, where a processing step should not always produce an output. Maybe the purpose is to filter input. Here the functional unit consumes words and produces words. But it does not pass along every word flowing in. Some words are swallowed. Think of a spell checker. It probably should not check acronyms for correctness. There are too many of them. Or words with no more than two letters. Such words are called “stop words”. In the above picture the optionality of the output is signified by the astrisk outside the brackets. It means: Any number of (word) data items can flow from the functional unit for each input data item. It might be none or one or even more. This I call a stream of data. Such behavior cannot be translated into a function where output is generated with return. Because a function always needs to return a value. So the output port is translated into a function pointer or continuation which gets passed to the subroutine when called:[3]void filter_stop_words( string word, Action<string> onNoStopWord) { if (...check if not a stop word...) onNoStopWord(word); } If you want to be nitpicky you might call such a function pointer parameter an injection. And technically you´re right. Conceptually, though, it´s not an injection. Because the subroutine is not functionally dependent on the continuation. Firstly continuations are procedures, i.e. subroutines without a return type. Remember: Flow Design is about unidirectional data flow. Secondly the name of the formal parameter is chosen in a way as to not assume anything about downstream processing steps. onNoStopWord describes a situation (or event) within the functional unit only. Translating output ports into function pointers helps keeping functional units mutually oblivious in cases where output is optional or produced asynchronically. Either pass the function pointer to the function upon call. Or make it global by putting it on the encompassing class. Then it´s called an event. In C# that´s even an explicit feature.class Filter { public void filter_stop_words( string word) { if (...check if not a stop word...) onNoStopWord(word); } public event Action<string> onNoStopWord; } When to use a continuation and when to use an event dependens on how a functional unit is used in flows and how it´s packed together with others into classes. You´ll see examples further down the Flow Design road. Another example of 1D functional design Let´s see Flow Design once more in action using the visual notation. How about the famous word wrap kata? Robert C. Martin has posted a much cited solution including an extensive reasoning behind his TDD approach. So maybe you want to compare it to Flow Design. The function signature given is:string WordWrap(string text, int maxLineLength) {...} That´s not an Entry Point since we don´t see an application with an environment and users. Nevertheless it´s a function which is supposed to provide a certain functionality. The text passed in has to be reformatted. The input is a single line of arbitrary length consisting of words separated by spaces. The output should consist of one or more lines of a maximum length specified. If a word is longer than a the maximum line length it can be split in multiple parts each fitting in a line. Flow Design Let´s start by brainstorming the process to accomplish the feat of reformatting the text. What´s needed? Words need to be assembled into lines Words need to be extracted from the input text The resulting lines need to be assembled into the output text Words too long to fit in a line need to be split Does sound about right? I guess so. And it shows a kind of priority. Long words are a special case. So maybe there is a hint for an incremental design here. First let´s tackle “average words” (words not longer than a line). Here´s the Flow Design for this increment: The the first three bullet points turned into functional units with explicit data added. As the signature requires a text is transformed into another text. See the input of the first functional unit and the output of the last functional unit. In between no text flows, but words and lines. That´s good to see because thereby the domain is clearly represented in the design. The requirements are talking about words and lines and here they are. But note the asterisk! It´s not outside the brackets but inside. That means it´s not a stream of words or lines, but lists or sequences. For each text a sequence of words is output. For each sequence of words a sequence of lines is produced. The asterisk is used to abstract from the concrete implementation. Like with streams. Whether the list of words gets implemented as an array or an IEnumerable is not important during design. It´s an implementation detail. Does any processing step require further refinement? I don´t think so. They all look pretty “atomic” to me. And if not… I can always backtrack and refine a process step using functional design later once I´ve gained more insight into a sub-problem. Implementation The implementation is straightforward as you can imagine. The processing steps can all be translated into functions. Each can be tested easily and separately. Each has a focused responsibility. And the process flow becomes just a sequence of function calls: Easy to understand. It clearly states how word wrapping works - on a high level of abstraction. And it´s easy to evolve as you´ll see. Flow Design - Increment 2 So far only texts consisting of “average words” are wrapped correctly. Words not fitting in a line will result in lines too long. Wrapping long words is a feature of the requested functionality. Whether it´s there or not makes a difference to the user. To quickly get feedback I decided to first implement a solution without this feature. But now it´s time to add it to deliver the full scope. Fortunately Flow Design automatically leads to code following the Open Closed Principle (OCP). It´s easy to extend it - instead of changing well tested code. How´s that possible? Flow Design allows for extension of functionality by inserting functional units into the flow. That way existing functional units need not be changed. The data flow arrow between functional units is a natural extension point. No need to resort to the Strategy Pattern. No need to think ahead where extions might need to be made in the future. I just “phase in” the remaining processing step: Since neither Extract words nor Reformat know of their environment neither needs to be touched due to the “detour”. The new processing step accepts the output of the existing upstream step and produces data compatible with the existing downstream step. Implementation - Increment 2 A trivial implementation checking the assumption if this works does not do anything to split long words. The input is just passed on: Note how clean WordWrap() stays. The solution is easy to understand. A developer looking at this code sometime in the future, when a new feature needs to be build in, quickly sees how long words are dealt with. Compare this to Robert C. Martin´s solution:[4] How does this solution handle long words? Long words are not even part of the domain language present in the code. At least I need considerable time to understand the approach. Admittedly the Flow Design solution with the full implementation of long word splitting is longer than Robert C. Martin´s. At least it seems. Because his solution does not cover all the “word wrap situations” the Flow Design solution handles. Some lines would need to be added to be on par, I guess. But even then… Is a difference in LOC that important as long as it´s in the same ball park? I value understandability and openness for extension higher than saving on the last line of code. Simplicity is not just less code, it´s also clarity in design. But don´t take my word for it. Try Flow Design on larger problems and compare for yourself. What´s the easier, more straightforward way to clean code? And keep in mind: You ain´t seen all yet ;-) There´s more to Flow Design than described in this chapter. In closing I hope I was able to give you a impression of functional design that makes you hungry for more. To me it´s an inevitable step in software development. Jumping from requirements to code does not scale. And it leads to dirty code all to quickly. Some thought should be invested first. Where there is a clear Entry Point visible, it´s functionality should be designed using data flows. Because with data flows abstraction is possible. For more background on why that´s necessary read my blog article here. For now let me point out to you - if you haven´t already noticed - that Flow Design is a general purpose declarative language. It´s “programming by intention” (Shalloway et al.). Just write down how you think the solution should work on a high level of abstraction. This breaks down a large problem in smaller problems. And by following the PoMO the solutions to those smaller problems are independent of each other. So they are easy to test. Or you could even think about getting them implemented in parallel by different team members. Flow Design not only increases evolvability, but also helps becoming more productive. All team members can participate in functional design. This goes beyon collective code ownership. We´re talking collective design/architecture ownership. Because with Flow Design there is a common visual language to talk about functional design - which is the foundation for all other design activities.   PS: If you like what you read, consider getting my ebook “The Incremental Architekt´s Napkin”. It´s where I compile all the articles in this series for easier reading. I like the strictness of Function Programming - but I also find it quite hard to live by. And it certainly is not what millions of programmers are used to. Also to me it seems, the real world is full of state and side effects. So why give them such a bad image? That´s why functional design takes a more pragmatic approach. State and side effects are ok for processing steps - but be sure to follow the SRP. Don´t put too much of it into a single processing step. ? Image taken from www.physioweb.org ? My code samples are written in C#. C# sports typed function pointers called delegates. Action is such a function pointer type matching functions with signature void someName(T t). Other languages provide similar ways to work with functions as first class citizens - even Java now in version 8. I trust you find a way to map this detail of my translation to your favorite programming language. I know it works for Java, C++, Ruby, JavaScript, Python, Go. And if you´re using a Functional Programming language it´s of course a no brainer. ? Taken from his blog post “The Craftsman 62, The Dark Path”. ?

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  • Zen and the Art of File and Folder Organization

    - by Mark Virtue
    Is your desk a paragon of neatness, or does it look like a paper-bomb has gone off? If you’ve been putting off getting organized because the task is too huge or daunting, or you don’t know where to start, we’ve got 40 tips to get you on the path to zen mastery of your filing system. For all those readers who would like to get their files and folders organized, or, if they’re already organized, better organized—we have compiled a complete guide to getting organized and staying organized, a comprehensive article that will hopefully cover every possible tip you could want. Signs that Your Computer is Poorly Organized If your computer is a mess, you’re probably already aware of it.  But just in case you’re not, here are some tell-tale signs: Your Desktop has over 40 icons on it “My Documents” contains over 300 files and 60 folders, including MP3s and digital photos You use the Windows’ built-in search facility whenever you need to find a file You can’t find programs in the out-of-control list of programs in your Start Menu You save all your Word documents in one folder, all your spreadsheets in a second folder, etc Any given file that you’re looking for may be in any one of four different sets of folders But before we start, here are some quick notes: We’re going to assume you know what files and folders are, and how to create, save, rename, copy and delete them The organization principles described in this article apply equally to all computer systems.  However, the screenshots here will reflect how things look on Windows (usually Windows 7).  We will also mention some useful features of Windows that can help you get organized. Everyone has their own favorite methodology of organizing and filing, and it’s all too easy to get into “My Way is Better than Your Way” arguments.  The reality is that there is no perfect way of getting things organized.  When I wrote this article, I tried to keep a generalist and objective viewpoint.  I consider myself to be unusually well organized (to the point of obsession, truth be told), and I’ve had 25 years experience in collecting and organizing files on computers.  So I’ve got a lot to say on the subject.  But the tips I have described here are only one way of doing it.  Hopefully some of these tips will work for you too, but please don’t read this as any sort of “right” way to do it. At the end of the article we’ll be asking you, the reader, for your own organization tips. Why Bother Organizing At All? For some, the answer to this question is self-evident. And yet, in this era of powerful desktop search software (the search capabilities built into the Windows Vista and Windows 7 Start Menus, and third-party programs like Google Desktop Search), the question does need to be asked, and answered. I have a friend who puts every file he ever creates, receives or downloads into his My Documents folder and doesn’t bother filing them into subfolders at all.  He relies on the search functionality built into his Windows operating system to help him find whatever he’s looking for.  And he always finds it.  He’s a Search Samurai.  For him, filing is a waste of valuable time that could be spent enjoying life! It’s tempting to follow suit.  On the face of it, why would anyone bother to take the time to organize their hard disk when such excellent search software is available?  Well, if all you ever want to do with the files you own is to locate and open them individually (for listening, editing, etc), then there’s no reason to ever bother doing one scrap of organization.  But consider these common tasks that are not achievable with desktop search software: Find files manually.  Often it’s not convenient, speedy or even possible to utilize your desktop search software to find what you want.  It doesn’t work 100% of the time, or you may not even have it installed.  Sometimes its just plain faster to go straight to the file you want, if you know it’s in a particular sub-folder, rather than trawling through hundreds of search results. Find groups of similar files (e.g. all your “work” files, all the photos of your Europe holiday in 2008, all your music videos, all the MP3s from Dark Side of the Moon, all your letters you wrote to your wife, all your tax returns).  Clever naming of the files will only get you so far.  Sometimes it’s the date the file was created that’s important, other times it’s the file format, and other times it’s the purpose of the file.  How do you name a collection of files so that they’re easy to isolate based on any of the above criteria?  Short answer, you can’t. Move files to a new computer.  It’s time to upgrade your computer.  How do you quickly grab all the files that are important to you?  Or you decide to have two computers now – one for home and one for work.  How do you quickly isolate only the work-related files to move them to the work computer? Synchronize files to other computers.  If you have more than one computer, and you need to mirror some of your files onto the other computer (e.g. your music collection), then you need a way to quickly determine which files are to be synced and which are not.  Surely you don’t want to synchronize everything? Choose which files to back up.  If your backup regime calls for multiple backups, or requires speedy backups, then you’ll need to be able to specify which files are to be backed up, and which are not.  This is not possible if they’re all in the same folder. Finally, if you’re simply someone who takes pleasure in being organized, tidy and ordered (me! me!), then you don’t even need a reason.  Being disorganized is simply unthinkable. Tips on Getting Organized Here we present our 40 best tips on how to get organized.  Or, if you’re already organized, to get better organized. Tip #1.  Choose Your Organization System Carefully The reason that most people are not organized is that it takes time.  And the first thing that takes time is deciding upon a system of organization.  This is always a matter of personal preference, and is not something that a geek on a website can tell you.  You should always choose your own system, based on how your own brain is organized (which makes the assumption that your brain is, in fact, organized). We can’t instruct you, but we can make suggestions: You may want to start off with a system based on the users of the computer.  i.e. “My Files”, “My Wife’s Files”, My Son’s Files”, etc.  Inside “My Files”, you might then break it down into “Personal” and “Business”.  You may then realize that there are overlaps.  For example, everyone may want to share access to the music library, or the photos from the school play.  So you may create another folder called “Family”, for the “common” files. You may decide that the highest-level breakdown of your files is based on the “source” of each file.  In other words, who created the files.  You could have “Files created by ME (business or personal)”, “Files created by people I know (family, friends, etc)”, and finally “Files created by the rest of the world (MP3 music files, downloaded or ripped movies or TV shows, software installation files, gorgeous desktop wallpaper images you’ve collected, etc).”  This system happens to be the one I use myself.  See below:  Mark is for files created by meVC is for files created by my company (Virtual Creations)Others is for files created by my friends and familyData is the rest of the worldAlso, Settings is where I store the configuration files and other program data files for my installed software (more on this in tip #34, below). Each folder will present its own particular set of requirements for further sub-organization.  For example, you may decide to organize your music collection into sub-folders based on the artist’s name, while your digital photos might get organized based on the date they were taken.  It can be different for every sub-folder! Another strategy would be based on “currentness”.  Files you have yet to open and look at live in one folder.  Ones that have been looked at but not yet filed live in another place.  Current, active projects live in yet another place.  All other files (your “archive”, if you like) would live in a fourth folder. (And of course, within that last folder you’d need to create a further sub-system based on one of the previous bullet points). Put some thought into this – changing it when it proves incomplete can be a big hassle!  Before you go to the trouble of implementing any system you come up with, examine a wide cross-section of the files you own and see if they will all be able to find a nice logical place to sit within your system. Tip #2.  When You Decide on Your System, Stick to It! There’s nothing more pointless than going to all the trouble of creating a system and filing all your files, and then whenever you create, receive or download a new file, you simply dump it onto your Desktop.  You need to be disciplined – forever!  Every new file you get, spend those extra few seconds to file it where it belongs!  Otherwise, in just a month or two, you’ll be worse off than before – half your files will be organized and half will be disorganized – and you won’t know which is which! Tip #3.  Choose the Root Folder of Your Structure Carefully Every data file (document, photo, music file, etc) that you create, own or is important to you, no matter where it came from, should be found within one single folder, and that one single folder should be located at the root of your C: drive (as a sub-folder of C:\).  In other words, do not base your folder structure in standard folders like “My Documents”.  If you do, then you’re leaving it up to the operating system engineers to decide what folder structure is best for you.  And every operating system has a different system!  In Windows 7 your files are found in C:\Users\YourName, whilst on Windows XP it was C:\Documents and Settings\YourName\My Documents.  In UNIX systems it’s often /home/YourName. These standard default folders tend to fill up with junk files and folders that are not at all important to you.  “My Documents” is the worst offender.  Every second piece of software you install, it seems, likes to create its own folder in the “My Documents” folder.  These folders usually don’t fit within your organizational structure, so don’t use them!  In fact, don’t even use the “My Documents” folder at all.  Allow it to fill up with junk, and then simply ignore it.  It sounds heretical, but: Don’t ever visit your “My Documents” folder!  Remove your icons/links to “My Documents” and replace them with links to the folders you created and you care about! Create your own file system from scratch!  Probably the best place to put it would be on your D: drive – if you have one.  This way, all your files live on one drive, while all the operating system and software component files live on the C: drive – simply and elegantly separated.  The benefits of that are profound.  Not only are there obvious organizational benefits (see tip #10, below), but when it comes to migrate your data to a new computer, you can (sometimes) simply unplug your D: drive and plug it in as the D: drive of your new computer (this implies that the D: drive is actually a separate physical disk, and not a partition on the same disk as C:).  You also get a slight speed improvement (again, only if your C: and D: drives are on separate physical disks). Warning:  From tip #12, below, you will see that it’s actually a good idea to have exactly the same file system structure – including the drive it’s filed on – on all of the computers you own.  So if you decide to use the D: drive as the storage system for your own files, make sure you are able to use the D: drive on all the computers you own.  If you can’t ensure that, then you can still use a clever geeky trick to store your files on the D: drive, but still access them all via the C: drive (see tip #17, below). If you only have one hard disk (C:), then create a dedicated folder that will contain all your files – something like C:\Files.  The name of the folder is not important, but make it a single, brief word. There are several reasons for this: When creating a backup regime, it’s easy to decide what files should be backed up – they’re all in the one folder! If you ever decide to trade in your computer for a new one, you know exactly which files to migrate You will always know where to begin a search for any file If you synchronize files with other computers, it makes your synchronization routines very simple.   It also causes all your shortcuts to continue to work on the other machines (more about this in tip #24, below). Once you’ve decided where your files should go, then put all your files in there – Everything!  Completely disregard the standard, default folders that are created for you by the operating system (“My Music”, “My Pictures”, etc).  In fact, you can actually relocate many of those folders into your own structure (more about that below, in tip #6). The more completely you get all your data files (documents, photos, music, etc) and all your configuration settings into that one folder, then the easier it will be to perform all of the above tasks. Once this has been done, and all your files live in one folder, all the other folders in C:\ can be thought of as “operating system” folders, and therefore of little day-to-day interest for us. Here’s a screenshot of a nicely organized C: drive, where all user files are located within the \Files folder:   Tip #4.  Use Sub-Folders This would be our simplest and most obvious tip.  It almost goes without saying.  Any organizational system you decide upon (see tip #1) will require that you create sub-folders for your files.  Get used to creating folders on a regular basis. Tip #5.  Don’t be Shy About Depth Create as many levels of sub-folders as you need.  Don’t be scared to do so.  Every time you notice an opportunity to group a set of related files into a sub-folder, do so.  Examples might include:  All the MP3s from one music CD, all the photos from one holiday, or all the documents from one client. It’s perfectly okay to put files into a folder called C:\Files\Me\From Others\Services\WestCo Bank\Statements\2009.  That’s only seven levels deep.  Ten levels is not uncommon.  Of course, it’s possible to take this too far.  If you notice yourself creating a sub-folder to hold only one file, then you’ve probably become a little over-zealous.  On the other hand, if you simply create a structure with only two levels (for example C:\Files\Work) then you really haven’t achieved any level of organization at all (unless you own only six files!).  Your “Work” folder will have become a dumping ground, just like your Desktop was, with most likely hundreds of files in it. Tip #6.  Move the Standard User Folders into Your Own Folder Structure Most operating systems, including Windows, create a set of standard folders for each of its users.  These folders then become the default location for files such as documents, music files, digital photos and downloaded Internet files.  In Windows 7, the full list is shown below: Some of these folders you may never use nor care about (for example, the Favorites folder, if you’re not using Internet Explorer as your browser).  Those ones you can leave where they are.  But you may be using some of the other folders to store files that are important to you.  Even if you’re not using them, Windows will still often treat them as the default storage location for many types of files.  When you go to save a standard file type, it can become annoying to be automatically prompted to save it in a folder that’s not part of your own file structure. But there’s a simple solution:  Move the folders you care about into your own folder structure!  If you do, then the next time you go to save a file of the corresponding type, Windows will prompt you to save it in the new, moved location. Moving the folders is easy.  Simply drag-and-drop them to the new location.  Here’s a screenshot of the default My Music folder being moved to my custom personal folder (Mark): Tip #7.  Name Files and Folders Intelligently This is another one that almost goes without saying, but we’ll say it anyway:  Do not allow files to be created that have meaningless names like Document1.doc, or folders called New Folder (2).  Take that extra 20 seconds and come up with a meaningful name for the file/folder – one that accurately divulges its contents without repeating the entire contents in the name. Tip #8.  Watch Out for Long Filenames Another way to tell if you have not yet created enough depth to your folder hierarchy is that your files often require really long names.  If you need to call a file Johnson Sales Figures March 2009.xls (which might happen to live in the same folder as Abercrombie Budget Report 2008.xls), then you might want to create some sub-folders so that the first file could be simply called March.xls, and living in the Clients\Johnson\Sales Figures\2009 folder. A well-placed file needs only a brief filename! Tip #9.  Use Shortcuts!  Everywhere! This is probably the single most useful and important tip we can offer.  A shortcut allows a file to be in two places at once. Why would you want that?  Well, the file and folder structure of every popular operating system on the market today is hierarchical.  This means that all objects (files and folders) always live within exactly one parent folder.  It’s a bit like a tree.  A tree has branches (folders) and leaves (files).  Each leaf, and each branch, is supported by exactly one parent branch, all the way back to the root of the tree (which, incidentally, is exactly why C:\ is called the “root folder” of the C: drive). That hard disks are structured this way may seem obvious and even necessary, but it’s only one way of organizing data.  There are others:  Relational databases, for example, organize structured data entirely differently.  The main limitation of hierarchical filing structures is that a file can only ever be in one branch of the tree – in only one folder – at a time.  Why is this a problem?  Well, there are two main reasons why this limitation is a problem for computer users: The “correct” place for a file, according to our organizational rationale, is very often a very inconvenient place for that file to be located.  Just because it’s correctly filed doesn’t mean it’s easy to get to.  Your file may be “correctly” buried six levels deep in your sub-folder structure, but you may need regular and speedy access to this file every day.  You could always move it to a more convenient location, but that would mean that you would need to re-file back to its “correct” location it every time you’d finished working on it.  Most unsatisfactory. A file may simply “belong” in two or more different locations within your file structure.  For example, say you’re an accountant and you have just completed the 2009 tax return for John Smith.  It might make sense to you to call this file 2009 Tax Return.doc and file it under Clients\John Smith.  But it may also be important to you to have the 2009 tax returns from all your clients together in the one place.  So you might also want to call the file John Smith.doc and file it under Tax Returns\2009.  The problem is, in a purely hierarchical filing system, you can’t put it in both places.  Grrrrr! Fortunately, Windows (and most other operating systems) offers a way for you to do exactly that:  It’s called a “shortcut” (also known as an “alias” on Macs and a “symbolic link” on UNIX systems).  Shortcuts allow a file to exist in one place, and an icon that represents the file to be created and put anywhere else you please.  In fact, you can create a dozen such icons and scatter them all over your hard disk.  Double-clicking on one of these icons/shortcuts opens up the original file, just as if you had double-clicked on the original file itself. Consider the following two icons: The one on the left is the actual Word document, while the one on the right is a shortcut that represents the Word document.  Double-clicking on either icon will open the same file.  There are two main visual differences between the icons: The shortcut will have a small arrow in the lower-left-hand corner (on Windows, anyway) The shortcut is allowed to have a name that does not include the file extension (the “.docx” part, in this case) You can delete the shortcut at any time without losing any actual data.  The original is still intact.  All you lose is the ability to get to that data from wherever the shortcut was. So why are shortcuts so great?  Because they allow us to easily overcome the main limitation of hierarchical file systems, and put a file in two (or more) places at the same time.  You will always have files that don’t play nice with your organizational rationale, and can’t be filed in only one place.  They demand to exist in two places.  Shortcuts allow this!  Furthermore, they allow you to collect your most often-opened files and folders together in one spot for convenient access.  The cool part is that the original files stay where they are, safe forever in their perfectly organized location. So your collection of most often-opened files can – and should – become a collection of shortcuts! If you’re still not convinced of the utility of shortcuts, consider the following well-known areas of a typical Windows computer: The Start Menu (and all the programs that live within it) The Quick Launch bar (or the Superbar in Windows 7) The “Favorite folders” area in the top-left corner of the Windows Explorer window (in Windows Vista or Windows 7) Your Internet Explorer Favorites or Firefox Bookmarks Each item in each of these areas is a shortcut!  Each of those areas exist for one purpose only:  For convenience – to provide you with a collection of the files and folders you access most often. It should be easy to see by now that shortcuts are designed for one single purpose:  To make accessing your files more convenient.  Each time you double-click on a shortcut, you are saved the hassle of locating the file (or folder, or program, or drive, or control panel icon) that it represents. Shortcuts allow us to invent a golden rule of file and folder organization: “Only ever have one copy of a file – never have two copies of the same file.  Use a shortcut instead” (this rule doesn’t apply to copies created for backup purposes, of course!) There are also lesser rules, like “don’t move a file into your work area – create a shortcut there instead”, and “any time you find yourself frustrated with how long it takes to locate a file, create a shortcut to it and place that shortcut in a convenient location.” So how to we create these massively useful shortcuts?  There are two main ways: “Copy” the original file or folder (click on it and type Ctrl-C, or right-click on it and select Copy):  Then right-click in an empty area of the destination folder (the place where you want the shortcut to go) and select Paste shortcut: Right-drag (drag with the right mouse button) the file from the source folder to the destination folder.  When you let go of the mouse button at the destination folder, a menu pops up: Select Create shortcuts here. Note that when shortcuts are created, they are often named something like Shortcut to Budget Detail.doc (windows XP) or Budget Detail – Shortcut.doc (Windows 7).   If you don’t like those extra words, you can easily rename the shortcuts after they’re created, or you can configure Windows to never insert the extra words in the first place (see our article on how to do this). And of course, you can create shortcuts to folders too, not just to files! Bottom line: Whenever you have a file that you’d like to access from somewhere else (whether it’s convenience you’re after, or because the file simply belongs in two places), create a shortcut to the original file in the new location. Tip #10.  Separate Application Files from Data Files Any digital organization guru will drum this rule into you.  Application files are the components of the software you’ve installed (e.g. Microsoft Word, Adobe Photoshop or Internet Explorer).  Data files are the files that you’ve created for yourself using that software (e.g. Word Documents, digital photos, emails or playlists). Software gets installed, uninstalled and upgraded all the time.  Hopefully you always have the original installation media (or downloaded set-up file) kept somewhere safe, and can thus reinstall your software at any time.  This means that the software component files are of little importance.  Whereas the files you have created with that software is, by definition, important.  It’s a good rule to always separate unimportant files from important files. So when your software prompts you to save a file you’ve just created, take a moment and check out where it’s suggesting that you save the file.  If it’s suggesting that you save the file into the same folder as the software itself, then definitely don’t follow that suggestion.  File it in your own folder!  In fact, see if you can find the program’s configuration option that determines where files are saved by default (if it has one), and change it. Tip #11.  Organize Files Based on Purpose, Not on File Type If you have, for example a folder called Work\Clients\Johnson, and within that folder you have two sub-folders, Word Documents and Spreadsheets (in other words, you’re separating “.doc” files from “.xls” files), then chances are that you’re not optimally organized.  It makes little sense to organize your files based on the program that created them.  Instead, create your sub-folders based on the purpose of the file.  For example, it would make more sense to create sub-folders called Correspondence and Financials.  It may well be that all the files in a given sub-folder are of the same file-type, but this should be more of a coincidence and less of a design feature of your organization system. Tip #12.  Maintain the Same Folder Structure on All Your Computers In other words, whatever organizational system you create, apply it to every computer that you can.  There are several benefits to this: There’s less to remember.  No matter where you are, you always know where to look for your files If you copy or synchronize files from one computer to another, then setting up the synchronization job becomes very simple Shortcuts can be copied or moved from one computer to another with ease (assuming the original files are also copied/moved).  There’s no need to find the target of the shortcut all over again on the second computer Ditto for linked files (e.g Word documents that link to data in a separate Excel file), playlists, and any files that reference the exact file locations of other files. This applies even to the drive that your files are stored on.  If your files are stored on C: on one computer, make sure they’re stored on C: on all your computers.  Otherwise all your shortcuts, playlists and linked files will stop working! Tip #13.  Create an “Inbox” Folder Create yourself a folder where you store all files that you’re currently working on, or that you haven’t gotten around to filing yet.  You can think of this folder as your “to-do” list.  You can call it “Inbox” (making it the same metaphor as your email system), or “Work”, or “To-Do”, or “Scratch”, or whatever name makes sense to you.  It doesn’t matter what you call it – just make sure you have one! Once you have finished working on a file, you then move it from the “Inbox” to its correct location within your organizational structure. You may want to use your Desktop as this “Inbox” folder.  Rightly or wrongly, most people do.  It’s not a bad place to put such files, but be careful:  If you do decide that your Desktop represents your “to-do” list, then make sure that no other files find their way there.  In other words, make sure that your “Inbox”, wherever it is, Desktop or otherwise, is kept free of junk – stray files that don’t belong there. So where should you put this folder, which, almost by definition, lives outside the structure of the rest of your filing system?  Well, first and foremost, it has to be somewhere handy.  This will be one of your most-visited folders, so convenience is key.  Putting it on the Desktop is a great option – especially if you don’t have any other folders on your Desktop:  the folder then becomes supremely easy to find in Windows Explorer: You would then create shortcuts to this folder in convenient spots all over your computer (“Favorite Links”, “Quick Launch”, etc). Tip #14.  Ensure You have Only One “Inbox” Folder Once you’ve created your “Inbox” folder, don’t use any other folder location as your “to-do list”.  Throw every incoming or created file into the Inbox folder as you create/receive it.  This keeps the rest of your computer pristine and free of randomly created or downloaded junk.  The last thing you want to be doing is checking multiple folders to see all your current tasks and projects.  Gather them all together into one folder. Here are some tips to help ensure you only have one Inbox: Set the default “save” location of all your programs to this folder. Set the default “download” location for your browser to this folder. If this folder is not your desktop (recommended) then also see if you can make a point of not putting “to-do” files on your desktop.  This keeps your desktop uncluttered and Zen-like: (the Inbox folder is in the bottom-right corner) Tip #15.  Be Vigilant about Clearing Your “Inbox” Folder This is one of the keys to staying organized.  If you let your “Inbox” overflow (i.e. allow there to be more than, say, 30 files or folders in there), then you’re probably going to start feeling like you’re overwhelmed:  You’re not keeping up with your to-do list.  Once your Inbox gets beyond a certain point (around 30 files, studies have shown), then you’ll simply start to avoid it.  You may continue to put files in there, but you’ll be scared to look at it, fearing the “out of control” feeling that all overworked, chaotic or just plain disorganized people regularly feel. So, here’s what you can do: Visit your Inbox/to-do folder regularly (at least five times per day). Scan the folder regularly for files that you have completed working on and are ready for filing.  File them immediately. Make it a source of pride to keep the number of files in this folder as small as possible.  If you value peace of mind, then make the emptiness of this folder one of your highest (computer) priorities If you know that a particular file has been in the folder for more than, say, six weeks, then admit that you’re not actually going to get around to processing it, and move it to its final resting place. Tip #16.  File Everything Immediately, and Use Shortcuts for Your Active Projects As soon as you create, receive or download a new file, store it away in its “correct” folder immediately.  Then, whenever you need to work on it (possibly straight away), create a shortcut to it in your “Inbox” (“to-do”) folder or your desktop.  That way, all your files are always in their “correct” locations, yet you still have immediate, convenient access to your current, active files.  When you finish working on a file, simply delete the shortcut. Ideally, your “Inbox” folder – and your Desktop – should contain no actual files or folders.  They should simply contain shortcuts. Tip #17.  Use Directory Symbolic Links (or Junctions) to Maintain One Unified Folder Structure Using this tip, we can get around a potential hiccup that we can run into when creating our organizational structure – the issue of having more than one drive on our computer (C:, D:, etc).  We might have files we need to store on the D: drive for space reasons, and yet want to base our organized folder structure on the C: drive (or vice-versa). Your chosen organizational structure may dictate that all your files must be accessed from the C: drive (for example, the root folder of all your files may be something like C:\Files).  And yet you may still have a D: drive and wish to take advantage of the hundreds of spare Gigabytes that it offers.  Did you know that it’s actually possible to store your files on the D: drive and yet access them as if they were on the C: drive?  And no, we’re not talking about shortcuts here (although the concept is very similar). By using the shell command mklink, you can essentially take a folder that lives on one drive and create an alias for it on a different drive (you can do lots more than that with mklink – for a full rundown on this programs capabilities, see our dedicated article).  These aliases are called directory symbolic links (and used to be known as junctions).  You can think of them as “virtual” folders.  They function exactly like regular folders, except they’re physically located somewhere else. For example, you may decide that your entire D: drive contains your complete organizational file structure, but that you need to reference all those files as if they were on the C: drive, under C:\Files.  If that was the case you could create C:\Files as a directory symbolic link – a link to D:, as follows: mklink /d c:\files d:\ Or it may be that the only files you wish to store on the D: drive are your movie collection.  You could locate all your movie files in the root of your D: drive, and then link it to C:\Files\Media\Movies, as follows: mklink /d c:\files\media\movies d:\ (Needless to say, you must run these commands from a command prompt – click the Start button, type cmd and press Enter) Tip #18. Customize Your Folder Icons This is not strictly speaking an organizational tip, but having unique icons for each folder does allow you to more quickly visually identify which folder is which, and thus saves you time when you’re finding files.  An example is below (from my folder that contains all files downloaded from the Internet): To learn how to change your folder icons, please refer to our dedicated article on the subject. Tip #19.  Tidy Your Start Menu The Windows Start Menu is usually one of the messiest parts of any Windows computer.  Every program you install seems to adopt a completely different approach to placing icons in this menu.  Some simply put a single program icon.  Others create a folder based on the name of the software.  And others create a folder based on the name of the software manufacturer.  It’s chaos, and can make it hard to find the software you want to run. Thankfully we can avoid this chaos with useful operating system features like Quick Launch, the Superbar or pinned start menu items. Even so, it would make a lot of sense to get into the guts of the Start Menu itself and give it a good once-over.  All you really need to decide is how you’re going to organize your applications.  A structure based on the purpose of the application is an obvious candidate.  Below is an example of one such structure: In this structure, Utilities means software whose job it is to keep the computer itself running smoothly (configuration tools, backup software, Zip programs, etc).  Applications refers to any productivity software that doesn’t fit under the headings Multimedia, Graphics, Internet, etc. In case you’re not aware, every icon in your Start Menu is a shortcut and can be manipulated like any other shortcut (copied, moved, deleted, etc). With the Windows Start Menu (all version of Windows), Microsoft has decided that there be two parallel folder structures to store your Start Menu shortcuts.  One for you (the logged-in user of the computer) and one for all users of the computer.  Having two parallel structures can often be redundant:  If you are the only user of the computer, then having two parallel structures is totally redundant.  Even if you have several users that regularly log into the computer, most of your installed software will need to be made available to all users, and should thus be moved out of the “just you” version of the Start Menu and into the “all users” area. To take control of your Start Menu, so you can start organizing it, you’ll need to know how to access the actual folders and shortcut files that make up the Start Menu (both versions of it).  To find these folders and files, click the Start button and then right-click on the All Programs text (Windows XP users should right-click on the Start button itself): The Open option refers to the “just you” version of the Start Menu, while the Open All Users option refers to the “all users” version.  Click on the one you want to organize. A Windows Explorer window then opens with your chosen version of the Start Menu selected.  From there it’s easy.  Double-click on the Programs folder and you’ll see all your folders and shortcuts.  Now you can delete/rename/move until it’s just the way you want it. Note:  When you’re reorganizing your Start Menu, you may want to have two Explorer windows open at the same time – one showing the “just you” version and one showing the “all users” version.  You can drag-and-drop between the windows. Tip #20.  Keep Your Start Menu Tidy Once you have a perfectly organized Start Menu, try to be a little vigilant about keeping it that way.  Every time you install a new piece of software, the icons that get created will almost certainly violate your organizational structure. So to keep your Start Menu pristine and organized, make sure you do the following whenever you install a new piece of software: Check whether the software was installed into the “just you” area of the Start Menu, or the “all users” area, and then move it to the correct area. Remove all the unnecessary icons (like the “Read me” icon, the “Help” icon (you can always open the help from within the software itself when it’s running), the “Uninstall” icon, the link(s)to the manufacturer’s website, etc) Rename the main icon(s) of the software to something brief that makes sense to you.  For example, you might like to rename Microsoft Office Word 2010 to simply Word Move the icon(s) into the correct folder based on your Start Menu organizational structure And don’t forget:  when you uninstall a piece of software, the software’s uninstall routine is no longer going to be able to remove the software’s icon from the Start Menu (because you moved and/or renamed it), so you’ll need to remove that icon manually. Tip #21.  Tidy C:\ The root of your C: drive (C:\) is a common dumping ground for files and folders – both by the users of your computer and by the software that you install on your computer.  It can become a mess. There’s almost no software these days that requires itself to be installed in C:\.  99% of the time it can and should be installed into C:\Program Files.  And as for your own files, well, it’s clear that they can (and almost always should) be stored somewhere else. In an ideal world, your C:\ folder should look like this (on Windows 7): Note that there are some system files and folders in C:\ that are usually and deliberately “hidden” (such as the Windows virtual memory file pagefile.sys, the boot loader file bootmgr, and the System Volume Information folder).  Hiding these files and folders is a good idea, as they need to stay where they are and are almost never needed to be opened or even seen by you, the user.  Hiding them prevents you from accidentally messing with them, and enhances your sense of order and well-being when you look at your C: drive folder. Tip #22.  Tidy Your Desktop The Desktop is probably the most abused part of a Windows computer (from an organization point of view).  It usually serves as a dumping ground for all incoming files, as well as holding icons to oft-used applications, plus some regularly opened files and folders.  It often ends up becoming an uncontrolled mess.  See if you can avoid this.  Here’s why… Application icons (Word, Internet Explorer, etc) are often found on the Desktop, but it’s unlikely that this is the optimum place for them.  The “Quick Launch” bar (or the Superbar in Windows 7) is always visible and so represents a perfect location to put your icons.  You’ll only be able to see the icons on your Desktop when all your programs are minimized.  It might be time to get your application icons off your desktop… You may have decided that the Inbox/To-do folder on your computer (see tip #13, above) should be your Desktop.  If so, then enough said.  Simply be vigilant about clearing it and preventing it from being polluted by junk files (see tip #15, above).  On the other hand, if your Desktop is not acting as your “Inbox” folder, then there’s no reason for it to have any data files or folders on it at all, except perhaps a couple of shortcuts to often-opened files and folders (either ongoing or current projects).  Everything else should be moved to your “Inbox” folder. In an ideal world, it might look like this: Tip #23.  Move Permanent Items on Your Desktop Away from the Top-Left Corner When files/folders are dragged onto your desktop in a Windows Explorer window, or when shortcuts are created on your Desktop from Internet Explorer, those icons are always placed in the top-left corner – or as close as they can get.  If you have other files, folders or shortcuts that you keep on the Desktop permanently, then it’s a good idea to separate these permanent icons from the transient ones, so that you can quickly identify which ones the transients are.  An easy way to do this is to move all your permanent icons to the right-hand side of your Desktop.  That should keep them separated from incoming items. Tip #24.  Synchronize If you have more than one computer, you’ll almost certainly want to share files between them.  If the computers are permanently attached to the same local network, then there’s no need to store multiple copies of any one file or folder – shortcuts will suffice.  However, if the computers are not always on the same network, then you will at some point need to copy files between them.  For files that need to permanently live on both computers, the ideal way to do this is to synchronize the files, as opposed to simply copying them. We only have room here to write a brief summary of synchronization, not a full article.  In short, there are several different types of synchronization: Where the contents of one folder are accessible anywhere, such as with Dropbox Where the contents of any number of folders are accessible anywhere, such as with Windows Live Mesh Where any files or folders from anywhere on your computer are synchronized with exactly one other computer, such as with the Windows “Briefcase”, Microsoft SyncToy, or (much more powerful, yet still free) SyncBack from 2BrightSparks.  This only works when both computers are on the same local network, at least temporarily. A great advantage of synchronization solutions is that once you’ve got it configured the way you want it, then the sync process happens automatically, every time.  Click a button (or schedule it to happen automatically) and all your files are automagically put where they’re supposed to be. If you maintain the same file and folder structure on both computers, then you can also sync files depend upon the correct location of other files, like shortcuts, playlists and office documents that link to other office documents, and the synchronized files still work on the other computer! Tip #25.  Hide Files You Never Need to See If you have your files well organized, you will often be able to tell if a file is out of place just by glancing at the contents of a folder (for example, it should be pretty obvious if you look in a folder that contains all the MP3s from one music CD and see a Word document in there).  This is a good thing – it allows you to determine if there are files out of place with a quick glance.  Yet sometimes there are files in a folder that seem out of place but actually need to be there, such as the “folder art” JPEGs in music folders, and various files in the root of the C: drive.  If such files never need to be opened by you, then a good idea is to simply hide them.  Then, the next time you glance at the folder, you won’t have to remember whether that file was supposed to be there or not, because you won’t see it at all! To hide a file, simply right-click on it and choose Properties: Then simply tick the Hidden tick-box:   Tip #26.  Keep Every Setup File These days most software is downloaded from the Internet.  Whenever you download a piece of software, keep it.  You’ll never know when you need to reinstall the software. Further, keep with it an Internet shortcut that links back to the website where you originally downloaded it, in case you ever need to check for updates. See tip #33 below for a full description of the excellence of organizing your setup files. Tip #27.  Try to Minimize the Number of Folders that Contain Both Files and Sub-folders Some of the folders in your organizational structure will contain only files.  Others will contain only sub-folders.  And you will also have some folders that contain both files and sub-folders.  You will notice slight improvements in how long it takes you to locate a file if you try to avoid this third type of folder.  It’s not always possible, of course – you’ll always have some of these folders, but see if you can avoid it. One way of doing this is to take all the leftover files that didn’t end up getting stored in a sub-folder and create a special “Miscellaneous” or “Other” folder for them. Tip #28.  Starting a Filename with an Underscore Brings it to the Top of a List Further to the previous tip, if you name that “Miscellaneous” or “Other” folder in such a way that its name begins with an underscore “_”, then it will appear at the top of the list of files/folders. The screenshot below is an example of this.  Each folder in the list contains a set of digital photos.  The folder at the top of the list, _Misc, contains random photos that didn’t deserve their own dedicated folder: Tip #29.  Clean Up those CD-ROMs and (shudder!) Floppy Disks Have you got a pile of CD-ROMs stacked on a shelf of your office?  Old photos, or files you archived off onto CD-ROM (or even worse, floppy disks!) because you didn’t have enough disk space at the time?  In the meantime have you upgraded your computer and now have 500 Gigabytes of space you don’t know what to do with?  If so, isn’t it time you tidied up that stack of disks and filed them into your gorgeous new folder structure? So what are you waiting for?  Bite the bullet, copy them all back onto your computer, file them in their appropriate folders, and then back the whole lot up onto a shiny new 1000Gig external hard drive! Useful Folders to Create This next section suggests some useful folders that you might want to create within your folder structure.  I’ve personally found them to be indispensable. The first three are all about convenience – handy folders to create and then put somewhere that you can always access instantly.  For each one, it’s not so important where the actual folder is located, but it’s very important where you put the shortcut(s) to the folder.  You might want to locate the shortcuts: On your Desktop In your “Quick Launch” area (or pinned to your Windows 7 Superbar) In your Windows Explorer “Favorite Links” area Tip #30.  Create an “Inbox” (“To-Do”) Folder This has already been mentioned in depth (see tip #13), but we wanted to reiterate its importance here.  This folder contains all the recently created, received or downloaded files that you have not yet had a chance to file away properly, and it also may contain files that you have yet to process.  In effect, it becomes a sort of “to-do list”.  It doesn’t have to be called “Inbox” – you can call it whatever you want. Tip #31.  Create a Folder where Your Current Projects are Collected Rather than going hunting for them all the time, or dumping them all on your desktop, create a special folder where you put links (or work folders) for each of the projects you’re currently working on. You can locate this folder in your “Inbox” folder, on your desktop, or anywhere at all – just so long as there’s a way of getting to it quickly, such as putting a link to it in Windows Explorer’s “Favorite Links” area: Tip #32.  Create a Folder for Files and Folders that You Regularly Open You will always have a few files that you open regularly, whether it be a spreadsheet of your current accounts, or a favorite playlist.  These are not necessarily “current projects”, rather they’re simply files that you always find yourself opening.  Typically such files would be located on your desktop (or even better, shortcuts to those files).  Why not collect all such shortcuts together and put them in their own special folder? As with the “Current Projects” folder (above), you would want to locate that folder somewhere convenient.  Below is an example of a folder called “Quick links”, with about seven files (shortcuts) in it, that is accessible through the Windows Quick Launch bar: See tip #37 below for a full explanation of the power of the Quick Launch bar. Tip #33.  Create a “Set-ups” Folder A typical computer has dozens of applications installed on it.  For each piece of software, there are often many different pieces of information you need to keep track of, including: The original installation setup file(s).  This can be anything from a simple 100Kb setup.exe file you downloaded from a website, all the way up to a 4Gig ISO file that you copied from a DVD-ROM that you purchased. The home page of the software manufacturer (in case you need to look up something on their support pages, their forum or their online help) The page containing the download link for your actual file (in case you need to re-download it, or download an upgraded version) The serial number Your proof-of-purchase documentation Any other template files, plug-ins, themes, etc that also need to get installed For each piece of software, it’s a great idea to gather all of these files together and put them in a single folder.  The folder can be the name of the software (plus possibly a very brief description of what it’s for – in case you can’t remember what the software does based in its name).  Then you would gather all of these folders together into one place, and call it something like “Software” or “Setups”. If you have enough of these folders (I have several hundred, being a geek, collected over 20 years), then you may want to further categorize them.  My own categorization structure is based on “platform” (operating system): The last seven folders each represents one platform/operating system, while _Operating Systems contains set-up files for installing the operating systems themselves.  _Hardware contains ROMs for hardware I own, such as routers. Within the Windows folder (above), you can see the beginnings of the vast library of software I’ve compiled over the years: An example of a typical application folder looks like this: Tip #34.  Have a “Settings” Folder We all know that our documents are important.  So are our photos and music files.  We save all of these files into folders, and then locate them afterwards and double-click on them to open them.  But there are many files that are important to us that can’t be saved into folders, and then searched for and double-clicked later on.  These files certainly contain important information that we need, but are often created internally by an application, and saved wherever that application feels is appropriate. A good example of this is the “PST” file that Outlook creates for us and uses to store all our emails, contacts, appointments and so forth.  Another example would be the collection of Bookmarks that Firefox stores on your behalf. And yet another example would be the customized settings and configuration files of our all our software.  Granted, most Windows programs store their configuration in the Registry, but there are still many programs that use configuration files to store their settings. Imagine if you lost all of the above files!  And yet, when people are backing up their computers, they typically only back up the files they know about – those that are stored in the “My Documents” folder, etc.  If they had a hard disk failure or their computer was lost or stolen, their backup files would not include some of the most vital files they owned.  Also, when migrating to a new computer, it’s vital to ensure that these files make the journey. It can be a very useful idea to create yourself a folder to store all your “settings” – files that are important to you but which you never actually search for by name and double-click on to open them.  Otherwise, next time you go to set up a new computer just the way you want it, you’ll need to spend hours recreating the configuration of your previous computer! So how to we get our important files into this folder?  Well, we have a few options: Some programs (such as Outlook and its PST files) allow you to place these files wherever you want.  If you delve into the program’s options, you will find a setting somewhere that controls the location of the important settings files (or “personal storage” – PST – when it comes to Outlook) Some programs do not allow you to change such locations in any easy way, but if you get into the Registry, you can sometimes find a registry key that refers to the location of the file(s).  Simply move the file into your Settings folder and adjust the registry key to refer to the new location. Some programs stubbornly refuse to allow their settings files to be placed anywhere other then where they stipulate.  When faced with programs like these, you have three choices:  (1) You can ignore those files, (2) You can copy the files into your Settings folder (let’s face it – settings don’t change very often), or (3) you can use synchronization software, such as the Windows Briefcase, to make synchronized copies of all your files in your Settings folder.  All you then have to do is to remember to run your sync software periodically (perhaps just before you run your backup software!). There are some other things you may decide to locate inside this new “Settings” folder: Exports of registry keys (from the many applications that store their configurations in the Registry).  This is useful for backup purposes or for migrating to a new computer Notes you’ve made about all the specific customizations you have made to a particular piece of software (so that you’ll know how to do it all again on your next computer) Shortcuts to webpages that detail how to tweak certain aspects of your operating system or applications so they are just the way you like them (such as how to remove the words “Shortcut to” from the beginning of newly created shortcuts).  In other words, you’d want to create shortcuts to half the pages on the How-To Geek website! Here’s an example of a “Settings” folder: Windows Features that Help with Organization This section details some of the features of Microsoft Windows that are a boon to anyone hoping to stay optimally organized. Tip #35.  Use the “Favorite Links” Area to Access Oft-Used Folders Once you’ve created your great new filing system, work out which folders you access most regularly, or which serve as great starting points for locating the rest of the files in your folder structure, and then put links to those folders in your “Favorite Links” area of the left-hand side of the Windows Explorer window (simply called “Favorites” in Windows 7):   Some ideas for folders you might want to add there include: Your “Inbox” folder (or whatever you’ve called it) – most important! The base of your filing structure (e.g. C:\Files) A folder containing shortcuts to often-accessed folders on other computers around the network (shown above as Network Folders) A folder containing shortcuts to your current projects (unless that folder is in your “Inbox” folder) Getting folders into this area is very simple – just locate the folder you’re interested in and drag it there! Tip #36.  Customize the Places Bar in the File/Open and File/Save Boxes Consider the screenshot below: The highlighted icons (collectively known as the “Places Bar”) can be customized to refer to any folder location you want, allowing instant access to any part of your organizational structure. Note:  These File/Open and File/Save boxes have been superseded by new versions that use the Windows Vista/Windows 7 “Favorite Links”, but the older versions (shown above) are still used by a surprisingly large number of applications. The easiest way to customize these icons is to use the Group Policy Editor, but not everyone has access to this program.  If you do, open it up and navigate to: User Configuration > Administrative Templates > Windows Components > Windows Explorer > Common Open File Dialog If you don’t have access to the Group Policy Editor, then you’ll need to get into the Registry.  Navigate to: HKEY_CURRENT_USER \ Software \ Microsoft  \ Windows \ CurrentVersion \ Policies \ comdlg32 \ Placesbar It should then be easy to make the desired changes.  Log off and log on again to allow the changes to take effect. Tip #37.  Use the Quick Launch Bar as a Application and File Launcher That Quick Launch bar (to the right of the Start button) is a lot more useful than people give it credit for.  Most people simply have half a dozen icons in it, and use it to start just those programs.  But it can actually be used to instantly access just about anything in your filing system: For complete instructions on how to set this up, visit our dedicated article on this topic. Tip #38.  Put a Shortcut to Windows Explorer into Your Quick Launch Bar This is only necessary in Windows Vista and Windows XP.  The Microsoft boffins finally got wise and added it to the Windows 7 Superbar by default. Windows Explorer – the program used for managing your files and folders – is one of the most useful programs in Windows.  Anyone who considers themselves serious about being organized needs instant access to this program at any time.  A great place to create a shortcut to this program is in the Windows XP and Windows Vista “Quick Launch” bar: To get it there, locate it in your Start Menu (usually under “Accessories”) and then right-drag it down into your Quick Launch bar (and create a copy). Tip #39.  Customize the Starting Folder for Your Windows 7 Explorer Superbar Icon If you’re on Windows 7, your Superbar will include a Windows Explorer icon.  Clicking on the icon will launch Windows Explorer (of course), and will start you off in your “Libraries” folder.  Libraries may be fine as a starting point, but if you have created yourself an “Inbox” folder, then it would probably make more sense to start off in this folder every time you launch Windows Explorer. To change this default/starting folder location, then first right-click the Explorer icon in the Superbar, and then right-click Properties:Then, in Target field of the Windows Explorer Properties box that appears, type %windir%\explorer.exe followed by the path of the folder you wish to start in.  For example: %windir%\explorer.exe C:\Files If that folder happened to be on the Desktop (and called, say, “Inbox”), then you would use the following cleverness: %windir%\explorer.exe shell:desktop\Inbox Then click OK and test it out. Tip #40.  Ummmmm…. No, that’s it.  I can’t think of another one.  That’s all of the tips I can come up with.  I only created this one because 40 is such a nice round number… Case Study – An Organized PC To finish off the article, I have included a few screenshots of my (main) computer (running Vista).  The aim here is twofold: To give you a sense of what it looks like when the above, sometimes abstract, tips are applied to a real-life computer, and To offer some ideas about folders and structure that you may want to steal to use on your own PC. Let’s start with the C: drive itself.  Very minimal.  All my files are contained within C:\Files.  I’ll confine the rest of the case study to this folder: That folder contains the following: Mark: My personal files VC: My business (Virtual Creations, Australia) Others contains files created by friends and family Data contains files from the rest of the world (can be thought of as “public” files, usually downloaded from the Net) Settings is described above in tip #34 The Data folder contains the following sub-folders: Audio:  Radio plays, audio books, podcasts, etc Development:  Programmer and developer resources, sample source code, etc (see below) Humour:  Jokes, funnies (those emails that we all receive) Movies:  Downloaded and ripped movies (all legal, of course!), their scripts, DVD covers, etc. Music:  (see below) Setups:  Installation files for software (explained in full in tip #33) System:  (see below) TV:  Downloaded TV shows Writings:  Books, instruction manuals, etc (see below) The Music folder contains the following sub-folders: Album covers:  JPEG scans Guitar tabs:  Text files of guitar sheet music Lists:  e.g. “Top 1000 songs of all time” Lyrics:  Text files MIDI:  Electronic music files MP3 (representing 99% of the Music folder):  MP3s, either ripped from CDs or downloaded, sorted by artist/album name Music Video:  Video clips Sheet Music:  usually PDFs The Data\Writings folder contains the following sub-folders: (all pretty self-explanatory) The Data\Development folder contains the following sub-folders: Again, all pretty self-explanatory (if you’re a geek) The Data\System folder contains the following sub-folders: These are usually themes, plug-ins and other downloadable program-specific resources. The Mark folder contains the following sub-folders: From Others:  Usually letters that other people (friends, family, etc) have written to me For Others:  Letters and other things I have created for other people Green Book:  None of your business Playlists:  M3U files that I have compiled of my favorite songs (plus one M3U playlist file for every album I own) Writing:  Fiction, philosophy and other musings of mine Mark Docs:  Shortcut to C:\Users\Mark Settings:  Shortcut to C:\Files\Settings\Mark The Others folder contains the following sub-folders: The VC (Virtual Creations, my business – I develop websites) folder contains the following sub-folders: And again, all of those are pretty self-explanatory. Conclusion These tips have saved my sanity and helped keep me a productive geek, but what about you? What tips and tricks do you have to keep your files organized?  Please share them with us in the comments.  Come on, don’t be shy… Similar Articles Productive Geek Tips Fix For When Windows Explorer in Vista Stops Showing File NamesWhy Did Windows Vista’s Music Folder Icon Turn Yellow?Print or Create a Text File List of the Contents in a Directory the Easy WayCustomize the Windows 7 or Vista Send To MenuAdd Copy To / Move To on Windows 7 or Vista Right-Click Menu TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips Acronis Online Backup DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows Track Daily Goals With 42Goals Video Toolbox is a Superb Online Video Editor Fun with 47 charts and graphs Tomorrow is Mother’s Day Check the Average Speed of YouTube Videos You’ve Watched OutlookStatView Scans and Displays General Usage Statistics

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  • Is there a Telecommunications Reference Architecture?

    - by raul.goycoolea
    @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Abstract   Reference architecture provides needed architectural information that can be provided in advance to an enterprise to enable consistent architectural best practices. Enterprise Reference Architecture helps business owners to actualize their strategies, vision, objectives, and principles. It evaluates the IT systems, based on Reference Architecture goals, principles, and standards. It helps to reduce IT costs by increasing functionality, availability, scalability, etc. Telecom Reference Architecture provides customers with the flexibility to view bundled service bills online with the provision of multiple services. It provides real-time, flexible billing and charging systems, to handle complex promotions, discounts, and settlements with multiple parties. This paper attempts to describe the Reference Architecture for the Telecom Enterprises. It lays the foundation for a Telecom Reference Architecture by articulating the requirements, drivers, and pitfalls for telecom service providers. It describes generic reference architecture for telecom enterprises and moves on to explain how to achieve Enterprise Reference Architecture by using SOA.   Introduction   A Reference Architecture provides a methodology, set of practices, template, and standards based on a set of successful solutions implemented earlier. These solutions have been generalized and structured for the depiction of both a logical and a physical architecture, based on the harvesting of a set of patterns that describe observations in a number of successful implementations. It helps as a reference for the various architectures that an enterprise can implement to solve various problems. It can be used as the starting point or the point of comparisons for various departments/business entities of a company, or for the various companies for an enterprise. It provides multiple views for multiple stakeholders.   Major artifacts of the Enterprise Reference Architecture are methodologies, standards, metadata, documents, design patterns, etc.   Purpose of Reference Architecture   In most cases, architects spend a lot of time researching, investigating, defining, and re-arguing architectural decisions. It is like reinventing the wheel as their peers in other organizations or even the same organization have already spent a lot of time and effort defining their own architectural practices. This prevents an organization from learning from its own experiences and applying that knowledge for increased effectiveness.   Reference architecture provides missing architectural information that can be provided in advance to project team members to enable consistent architectural best practices.   Enterprise Reference Architecture helps an enterprise to achieve the following at the abstract level:   ·       Reference architecture is more of a communication channel to an enterprise ·       Helps the business owners to accommodate to their strategies, vision, objectives, and principles. ·       Evaluates the IT systems based on Reference Architecture Principles ·       Reduces IT spending through increasing functionality, availability, scalability, etc ·       A Real-time Integration Model helps to reduce the latency of the data updates Is used to define a single source of Information ·       Provides a clear view on how to manage information and security ·       Defines the policy around the data ownership, product boundaries, etc. ·       Helps with cost optimization across project and solution portfolios by eliminating unused or duplicate investments and assets ·       Has a shorter implementation time and cost   Once the reference architecture is in place, the set of architectural principles, standards, reference models, and best practices ensure that the aligned investments have the greatest possible likelihood of success in both the near term and the long term (TCO).     Common pitfalls for Telecom Service Providers   Telecom Reference Architecture serves as the first step towards maturity for a telecom service provider. During the course of our assignments/experiences with telecom players, we have come across the following observations – Some of these indicate a lack of maturity of the telecom service provider:   ·       In markets that are growing and not so mature, it has been observed that telcos have a significant amount of in-house or home-grown applications. In some of these markets, the growth has been so rapid that IT has been unable to cope with business demands. Telcos have shown a tendency to come up with workarounds in their IT applications so as to meet business needs. ·       Even for core functions like provisioning or mediation, some telcos have tried to manage with home-grown applications. ·       Most of the applications do not have the required scalability or maintainability to sustain growth in volumes or functionality. ·       Applications face interoperability issues with other applications in the operator's landscape. Integrating a new application or network element requires considerable effort on the part of the other applications. ·       Application boundaries are not clear, and functionality that is not in the initial scope of that application gets pushed onto it. This results in the development of the multiple, small applications without proper boundaries. ·       Usage of Legacy OSS/BSS systems, poor Integration across Multiple COTS Products and Internal Systems. Most of the Integrations are developed on ad-hoc basis and Point-to-Point Integration. ·       Redundancy of the business functions in different applications • Fragmented data across the different applications and no integrated view of the strategic data • Lot of performance Issues due to the usage of the complex integration across OSS and BSS systems   However, this is where the maturity of the telecom industry as a whole can be of help. The collaborative efforts of telcos to overcome some of these problems have resulted in bodies like the TM Forum. They have come up with frameworks for business processes, data, applications, and technology for telecom service providers. These could be a good starting point for telcos to clean up their enterprise landscape.   Industry Trends in Telecom Reference Architecture   Telecom reference architectures are evolving rapidly because telcos are facing business and IT challenges.   “The reality is that there probably is no killer application, no silver bullet that the telcos can latch onto to carry them into a 21st Century.... Instead, there are probably hundreds – perhaps thousands – of niche applications.... And the only way to find which of these works for you is to try out lots of them, ramp up the ones that work, and discontinue the ones that fail.” – Martin Creaner President & CTO TM Forum.   The following trends have been observed in telecom reference architecture:   ·       Transformation of business structures to align with customer requirements ·       Adoption of more Internet-like technical architectures. The Web 2.0 concept is increasingly being used. ·       Virtualization of the traditional operations support system (OSS) ·       Adoption of SOA to support development of IP-based services ·       Adoption of frameworks like Service Delivery Platforms (SDPs) and IP Multimedia Subsystem ·       (IMS) to enable seamless deployment of various services over fixed and mobile networks ·       Replacement of in-house, customized, and stove-piped OSS/BSS with standards-based COTS products ·       Compliance with industry standards and frameworks like eTOM, SID, and TAM to enable seamless integration with other standards-based products   Drivers of Reference Architecture   The drivers of the Reference Architecture are Reference Architecture Goals, Principles, and Enterprise Vision and Telecom Transformation. The details are depicted below diagram. @font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }div.Section1 { page: Section1; } Figure 1. Drivers for Reference Architecture @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Today’s telecom reference architectures should seamlessly integrate traditional legacy-based applications and transition to next-generation network technologies (e.g., IP multimedia subsystems). This has resulted in new requirements for flexible, real-time billing and OSS/BSS systems and implications on the service provider’s organizational requirements and structure.   Telecom reference architectures are today expected to:   ·       Integrate voice, messaging, email and other VAS over fixed and mobile networks, back end systems ·       Be able to provision multiple services and service bundles • Deliver converged voice, video and data services ·       Leverage the existing Network Infrastructure ·       Provide real-time, flexible billing and charging systems to handle complex promotions, discounts, and settlements with multiple parties. ·       Support charging of advanced data services such as VoIP, On-Demand, Services (e.g.  Video), IMS/SIP Services, Mobile Money, Content Services and IPTV. ·       Help in faster deployment of new services • Serve as an effective platform for collaboration between network IT and business organizations ·       Harness the potential of converging technology, networks, devices and content to develop multimedia services and solutions of ever-increasing sophistication on a single Internet Protocol (IP) ·       Ensure better service delivery and zero revenue leakage through real-time balance and credit management ·       Lower operating costs to drive profitability   Enterprise Reference Architecture   The Enterprise Reference Architecture (RA) fills the gap between the concepts and vocabulary defined by the reference model and the implementation. Reference architecture provides detailed architectural information in a common format such that solutions can be repeatedly designed and deployed in a consistent, high-quality, supportable fashion. This paper attempts to describe the Reference Architecture for the Telecom Application Usage and how to achieve the Enterprise Level Reference Architecture using SOA.   • Telecom Reference Architecture • Enterprise SOA based Reference Architecture   Telecom Reference Architecture   Tele Management Forum’s New Generation Operations Systems and Software (NGOSS) is an architectural framework for organizing, integrating, and implementing telecom systems. NGOSS is a component-based framework consisting of the following elements:   ·       The enhanced Telecom Operations Map (eTOM) is a business process framework. ·       The Shared Information Data (SID) model provides a comprehensive information framework that may be specialized for the needs of a particular organization. ·       The Telecom Application Map (TAM) is an application framework to depict the functional footprint of applications, relative to the horizontal processes within eTOM. ·       The Technology Neutral Architecture (TNA) is an integrated framework. TNA is an architecture that is sustainable through technology changes.   NGOSS Architecture Standards are:   ·       Centralized data ·       Loosely coupled distributed systems ·       Application components/re-use  ·       A technology-neutral system framework with technology specific implementations ·       Interoperability to service provider data/processes ·       Allows more re-use of business components across multiple business scenarios ·       Workflow automation   The traditional operator systems architecture consists of four layers,   ·       Business Support System (BSS) layer, with focus toward customers and business partners. Manages order, subscriber, pricing, rating, and billing information. ·       Operations Support System (OSS) layer, built around product, service, and resource inventories. ·       Networks layer – consists of Network elements and 3rd Party Systems. ·       Integration Layer – to maximize application communication and overall solution flexibility.   Reference architecture for telecom enterprises is depicted below. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 2. Telecom Reference Architecture   The major building blocks of any Telecom Service Provider architecture are as follows:   1. Customer Relationship Management   CRM encompasses the end-to-end lifecycle of the customer: customer initiation/acquisition, sales, ordering, and service activation, customer care and support, proactive campaigns, cross sell/up sell, and retention/loyalty.   CRM also includes the collection of customer information and its application to personalize, customize, and integrate delivery of service to a customer, as well as to identify opportunities for increasing the value of the customer to the enterprise.   The key functionalities related to Customer Relationship Management are   ·       Manage the end-to-end lifecycle of a customer request for products. ·       Create and manage customer profiles. ·       Manage all interactions with customers – inquiries, requests, and responses. ·       Provide updates to Billing and other south bound systems on customer/account related updates such as customer/ account creation, deletion, modification, request bills, final bill, duplicate bills, credit limits through Middleware. ·       Work with Order Management System, Product, and Service Management components within CRM. ·       Manage customer preferences – Involve all the touch points and channels to the customer, including contact center, retail stores, dealers, self service, and field service, as well as via any media (phone, face to face, web, mobile device, chat, email, SMS, mail, the customer's bill, etc.). ·       Support single interface for customer contact details, preferences, account details, offers, customer premise equipment, bill details, bill cycle details, and customer interactions.   CRM applications interact with customers through customer touch points like portals, point-of-sale terminals, interactive voice response systems, etc. The requests by customers are sent via fulfillment/provisioning to billing system for ordering processing.   2. Billing and Revenue Management   Billing and Revenue Management handles the collection of appropriate usage records and production of timely and accurate bills – for providing pre-bill usage information and billing to customers; for processing their payments; and for performing payment collections. In addition, it handles customer inquiries about bills, provides billing inquiry status, and is responsible for resolving billing problems to the customer's satisfaction in a timely manner. This process grouping also supports prepayment for services.   The key functionalities provided by these applications are   ·       To ensure that enterprise revenue is billed and invoices delivered appropriately to customers. ·       To manage customers’ billing accounts, process their payments, perform payment collections, and monitor the status of the account balance. ·       To ensure the timely and effective fulfillment of all customer bill inquiries and complaints. ·       Collect the usage records from mediation and ensure appropriate rating and discounting of all usage and pricing. ·       Support revenue sharing; split charging where usage is guided to an account different from the service consumer. ·       Support prepaid and post-paid rating. ·       Send notification on approach / exceeding the usage thresholds as enforced by the subscribed offer, and / or as setup by the customer. ·       Support prepaid, post paid, and hybrid (where some services are prepaid and the rest of the services post paid) customers and conversion from post paid to prepaid, and vice versa. ·       Support different billing function requirements like charge prorating, promotion, discount, adjustment, waiver, write-off, account receivable, GL Interface, late payment fee, credit control, dunning, account or service suspension, re-activation, expiry, termination, contract violation penalty, etc. ·       Initiate direct debit to collect payment against an invoice outstanding. ·       Send notification to Middleware on different events; for example, payment receipt, pre-suspension, threshold exceed, etc.   Billing systems typically get usage data from mediation systems for rating and billing. They get provisioning requests from order management systems and inquiries from CRM systems. Convergent and real-time billing systems can directly get usage details from network elements.   3. Mediation   Mediation systems transform/translate the Raw or Native Usage Data Records into a general format that is acceptable to billing for their rating purposes.   The following lists the high-level roles and responsibilities executed by the Mediation system in the end-to-end solution.   ·       Collect Usage Data Records from different data sources – like network elements, routers, servers – via different protocol and interfaces. ·       Process Usage Data Records – Mediation will process Usage Data Records as per the source format. ·       Validate Usage Data Records from each source. ·       Segregates Usage Data Records coming from each source to multiple, based on the segregation requirement of end Application. ·       Aggregates Usage Data Records based on the aggregation rule if any from different sources. ·       Consolidates multiple Usage Data Records from each source. ·       Delivers formatted Usage Data Records to different end application like Billing, Interconnect, Fraud Management, etc. ·       Generates audit trail for incoming Usage Data Records and keeps track of all the Usage Data Records at various stages of mediation process. ·       Checks duplicate Usage Data Records across files for a given time window.   4. Fulfillment   This area is responsible for providing customers with their requested products in a timely and correct manner. It translates the customer's business or personal need into a solution that can be delivered using the specific products in the enterprise's portfolio. This process informs the customers of the status of their purchase order, and ensures completion on time, as well as ensuring a delighted customer. These processes are responsible for accepting and issuing orders. They deal with pre-order feasibility determination, credit authorization, order issuance, order status and tracking, customer update on customer order activities, and customer notification on order completion. Order management and provisioning applications fall into this category.   The key functionalities provided by these applications are   ·       Issuing new customer orders, modifying open customer orders, or canceling open customer orders; ·       Verifying whether specific non-standard offerings sought by customers are feasible and supportable; ·       Checking the credit worthiness of customers as part of the customer order process; ·       Testing the completed offering to ensure it is working correctly; ·       Updating of the Customer Inventory Database to reflect that the specific product offering has been allocated, modified, or cancelled; ·       Assigning and tracking customer provisioning activities; ·       Managing customer provisioning jeopardy conditions; and ·       Reporting progress on customer orders and other processes to customer.   These applications typically get orders from CRM systems. They interact with network elements and billing systems for fulfillment of orders.   5. Enterprise Management   This process area includes those processes that manage enterprise-wide activities and needs, or have application within the enterprise as a whole. They encompass all business management processes that   ·       Are necessary to support the whole of the enterprise, including processes for financial management, legal management, regulatory management, process, cost, and quality management, etc.;   ·       Are responsible for setting corporate policies, strategies, and directions, and for providing guidelines and targets for the whole of the business, including strategy development and planning for areas, such as Enterprise Architecture, that are integral to the direction and development of the business;   ·       Occur throughout the enterprise, including processes for project management, performance assessments, cost assessments, etc.     (i) Enterprise Risk Management:   Enterprise Risk Management focuses on assuring that risks and threats to the enterprise value and/or reputation are identified, and appropriate controls are in place to minimize or eliminate the identified risks. The identified risks may be physical or logical/virtual. Successful risk management ensures that the enterprise can support its mission critical operations, processes, applications, and communications in the face of serious incidents such as security threats/violations and fraud attempts. Two key areas covered in Risk Management by telecom operators are:   ·       Revenue Assurance: Revenue assurance system will be responsible for identifying revenue loss scenarios across components/systems, and will help in rectifying the problems. The following lists the high-level roles and responsibilities executed by the Revenue Assurance system in the end-to-end solution. o   Identify all usage information dropped when networks are being upgraded. o   Interconnect bill verification. o   Identify where services are routinely provisioned but never billed. o   Identify poor sales policies that are intensifying collections problems. o   Find leakage where usage is sent to error bucket and never billed for. o   Find leakage where field service, CRM, and network build-out are not optimized.   ·       Fraud Management: Involves collecting data from different systems to identify abnormalities in traffic patterns, usage patterns, and subscription patterns to report suspicious activity that might suggest fraudulent usage of resources, resulting in revenue losses to the operator.   The key roles and responsibilities of the system component are as follows:   o   Fraud management system will capture and monitor high usage (over a certain threshold) in terms of duration, value, and number of calls for each subscriber. The threshold for each subscriber is decided by the system and fixed automatically. o   Fraud management will be able to detect the unauthorized access to services for certain subscribers. These subscribers may have been provided unauthorized services by employees. The component will raise the alert to the operator the very first time of such illegal calls or calls which are not billed. o   The solution will be to have an alarm management system that will deliver alarms to the operator/provider whenever it detects a fraud, thus minimizing fraud by catching it the first time it occurs. o   The Fraud Management system will be capable of interfacing with switches, mediation systems, and billing systems   (ii) Knowledge Management   This process focuses on knowledge management, technology research within the enterprise, and the evaluation of potential technology acquisitions.   Key responsibilities of knowledge base management are to   ·       Maintain knowledge base – Creation and updating of knowledge base on ongoing basis. ·       Search knowledge base – Search of knowledge base on keywords or category browse ·       Maintain metadata – Management of metadata on knowledge base to ensure effective management and search. ·       Run report generator. ·       Provide content – Add content to the knowledge base, e.g., user guides, operational manual, etc.   (iii) Document Management   It focuses on maintaining a repository of all electronic documents or images of paper documents relevant to the enterprise using a system.   (iv) Data Management   It manages data as a valuable resource for any enterprise. For telecom enterprises, the typical areas covered are Master Data Management, Data Warehousing, and Business Intelligence. It is also responsible for data governance, security, quality, and database management.   Key responsibilities of Data Management are   ·       Using ETL, extract the data from CRM, Billing, web content, ERP, campaign management, financial, network operations, asset management info, customer contact data, customer measures, benchmarks, process data, e.g., process inputs, outputs, and measures, into Enterprise Data Warehouse. ·       Management of data traceability with source, data related business rules/decisions, data quality, data cleansing data reconciliation, competitors data – storage for all the enterprise data (customer profiles, products, offers, revenues, etc.) ·       Get online update through night time replication or physical backup process at regular frequency. ·       Provide the data access to business intelligence and other systems for their analysis, report generation, and use.   (v) Business Intelligence   It uses the Enterprise Data to provide the various analysis and reports that contain prospects and analytics for customer retention, acquisition of new customers due to the offers, and SLAs. It will generate right and optimized plans – bolt-ons for the customers.   The following lists the high-level roles and responsibilities executed by the Business Intelligence system at the Enterprise Level:   ·       It will do Pattern analysis and reports problem. ·       It will do Data Analysis – Statistical analysis, data profiling, affinity analysis of data, customer segment wise usage patterns on offers, products, service and revenue generation against services and customer segments. ·       It will do Performance (business, system, and forecast) analysis, churn propensity, response time, and SLAs analysis. ·       It will support for online and offline analysis, and report drill down capability. ·       It will collect, store, and report various SLA data. ·       It will provide the necessary intelligence for marketing and working on campaigns, etc., with cost benefit analysis and predictions.   It will advise on customer promotions with additional services based on loyalty and credit history of customer   ·       It will Interface with Enterprise Data Management system for data to run reports and analysis tasks. It will interface with the campaign schedules, based on historical success evidence.   (vi) Stakeholder and External Relations Management   It manages the enterprise's relationship with stakeholders and outside entities. Stakeholders include shareholders, employee organizations, etc. Outside entities include regulators, local community, and unions. Some of the processes within this grouping are Shareholder Relations, External Affairs, Labor Relations, and Public Relations.   (vii) Enterprise Resource Planning   It is used to manage internal and external resources, including tangible assets, financial resources, materials, and human resources. Its purpose is to facilitate the flow of information between all business functions inside the boundaries of the enterprise and manage the connections to outside stakeholders. ERP systems consolidate all business operations into a uniform and enterprise wide system environment.   The key roles and responsibilities for Enterprise System are given below:   ·        It will handle responsibilities such as core accounting, financial, and management reporting. ·       It will interface with CRM for capturing customer account and details. ·       It will interface with billing to capture the billing revenue and other financial data. ·       It will be responsible for executing the dunning process. Billing will send the required feed to ERP for execution of dunning. ·       It will interface with the CRM and Billing through batch interfaces. Enterprise management systems are like horizontals in the enterprise and typically interact with all major telecom systems. E.g., an ERP system interacts with CRM, Fulfillment, and Billing systems for different kinds of data exchanges.   6. External Interfaces/Touch Points   The typical external parties are customers, suppliers/partners, employees, shareholders, and other stakeholders. External interactions from/to a Service Provider to other parties can be achieved by a variety of mechanisms, including:   ·       Exchange of emails or faxes ·       Call Centers ·       Web Portals ·       Business-to-Business (B2B) automated transactions   These applications provide an Internet technology driven interface to external parties to undertake a variety of business functions directly for themselves. These can provide fully or partially automated service to external parties through various touch points.   Typical characteristics of these touch points are   ·       Pre-integrated self-service system, including stand-alone web framework or integration front end with a portal engine ·       Self services layer exposing atomic web services/APIs for reuse by multiple systems across the architectural environment ·       Portlets driven connectivity exposing data and services interoperability through a portal engine or web application   These touch points mostly interact with the CRM systems for requests, inquiries, and responses.   7. Middleware   The component will be primarily responsible for integrating the different systems components under a common platform. It should provide a Standards-Based Platform for building Service Oriented Architecture and Composite Applications. The following lists the high-level roles and responsibilities executed by the Middleware component in the end-to-end solution.   ·       As an integration framework, covering to and fro interfaces ·       Provide a web service framework with service registry. ·       Support SOA framework with SOA service registry. ·       Each of the interfaces from / to Middleware to other components would handle data transformation, translation, and mapping of data points. ·       Receive data from the caller / activate and/or forward the data to the recipient system in XML format. ·       Use standard XML for data exchange. ·       Provide the response back to the service/call initiator. ·       Provide a tracking until the response completion. ·       Keep a store transitional data against each call/transaction. ·       Interface through Middleware to get any information that is possible and allowed from the existing systems to enterprise systems; e.g., customer profile and customer history, etc. ·       Provide the data in a common unified format to the SOA calls across systems, and follow the Enterprise Architecture directive. ·       Provide an audit trail for all transactions being handled by the component.   8. Network Elements   The term Network Element means a facility or equipment used in the provision of a telecommunications service. Such terms also includes features, functions, and capabilities that are provided by means of such facility or equipment, including subscriber numbers, databases, signaling systems, and information sufficient for billing and collection or used in the transmission, routing, or other provision of a telecommunications service.   Typical network elements in a GSM network are Home Location Register (HLR), Intelligent Network (IN), Mobile Switching Center (MSC), SMS Center (SMSC), and network elements for other value added services like Push-to-talk (PTT), Ring Back Tone (RBT), etc.   Network elements are invoked when subscribers use their telecom devices for any kind of usage. These elements generate usage data and pass it on to downstream systems like mediation and billing system for rating and billing. They also integrate with provisioning systems for order/service fulfillment.   9. 3rd Party Applications   3rd Party systems are applications like content providers, payment gateways, point of sale terminals, and databases/applications maintained by the Government.   Depending on applicability and the type of functionality provided by 3rd party applications, the integration with different telecom systems like CRM, provisioning, and billing will be done.   10. Service Delivery Platform   A service delivery platform (SDP) provides the architecture for the rapid deployment, provisioning, execution, management, and billing of value added telecom services. SDPs are based on the concept of SOA and layered architecture. They support the delivery of voice, data services, and content in network and device-independent fashion. They allow application developers to aggregate network capabilities, services, and sources of content. SDPs typically contain layers for web services exposure, service application development, and network abstraction.   SOA Reference Architecture   SOA concept is based on the principle of developing reusable business service and building applications by composing those services, instead of building monolithic applications in silos. It’s about bridging the gap between business and IT through a set of business-aligned IT services, using a set of design principles, patterns, and techniques.   In an SOA, resources are made available to participants in a value net, enterprise, line of business (typically spanning multiple applications within an enterprise or across multiple enterprises). It consists of a set of business-aligned IT services that collectively fulfill an organization’s business processes and goals. We can choreograph these services into composite applications and invoke them through standard protocols. SOA, apart from agility and reusability, enables:   ·       The business to specify processes as orchestrations of reusable services ·       Technology agnostic business design, with technology hidden behind service interface ·       A contractual-like interaction between business and IT, based on service SLAs ·       Accountability and governance, better aligned to business services ·       Applications interconnections untangling by allowing access only through service interfaces, reducing the daunting side effects of change ·       Reduced pressure to replace legacy and extended lifetime for legacy applications, through encapsulation in services   ·       A Cloud Computing paradigm, using web services technologies, that makes possible service outsourcing on an on-demand, utility-like, pay-per-usage basis   The following section represents the Reference Architecture of logical view for the Telecom Solution. The new custom built application needs to align with this logical architecture in the long run to achieve EA benefits.   Packaged implementation applications, such as ERP billing applications, need to expose their functions as service providers (as other applications consume) and interact with other applications as service consumers.   COT applications need to expose services through wrappers such as adapters to utilize existing resources and at the same time achieve Enterprise Architecture goal and objectives.   The following are the various layers for Enterprise level deployment of SOA. This diagram captures the abstract view of Enterprise SOA layers and important components of each layer. Layered architecture means decomposition of services such that most interactions occur between adjacent layers. However, there is no strict rule that top layers should not directly communicate with bottom layers.   The diagram below represents the important logical pieces that would result from overall SOA transformation. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 3. Enterprise SOA Reference Architecture 1.          Operational System Layer: This layer consists of all packaged applications like CRM, ERP, custom built applications, COTS based applications like Billing, Revenue Management, Fulfilment, and the Enterprise databases that are essential and contribute directly or indirectly to the Enterprise OSS/BSS Transformation.   ERP holds the data of Asset Lifecycle Management, Supply Chain, and Advanced Procurement and Human Capital Management, etc.   CRM holds the data related to Order, Sales, and Marketing, Customer Care, Partner Relationship Management, Loyalty, etc.   Content Management handles Enterprise Search and Query. Billing application consists of the following components:   ·       Collections Management, Customer Billing Management, Invoices, Real-Time Rating, Discounting, and Applying of Charges ·       Enterprise databases will hold both the application and service data, whether structured or unstructured.   MDM - Master data majorly consists of Customer, Order, Product, and Service Data.     2.          Enterprise Component Layer:   This layer consists of the Application Services and Common Services that are responsible for realizing the functionality and maintaining the QoS of the exposed services. This layer uses container-based technologies such as application servers to implement the components, workload management, high availability, and load balancing.   Application Services: This Service Layer enables application, technology, and database abstraction so that the complex accessing logic is hidden from the other service layers. This is a basic service layer, which exposes application functionalities and data as reusable services. The three types of the Application access services are:   ·       Application Access Service: This Service Layer exposes application level functionalities as a reusable service between BSS to BSS and BSS to OSS integration. This layer is enabled using disparate technology such as Web Service, Integration Servers, and Adaptors, etc.   ·       Data Access Service: This Service Layer exposes application data services as a reusable reference data service. This is done via direct interaction with application data. and provides the federated query.   ·       Network Access Service: This Service Layer exposes provisioning layer as a reusable service from OSS to OSS integration. This integration service emphasizes the need for high performance, stateless process flows, and distributed design.   Common Services encompasses management of structured, semi-structured, and unstructured data such as information services, portal services, interaction services, infrastructure services, and security services, etc.   3.          Integration Layer:   This consists of service infrastructure components like service bus, service gateway for partner integration, service registry, service repository, and BPEL processor. Service bus will carry the service invocation payloads/messages between consumers and providers. The other important functions expected from it are itinerary based routing, distributed caching of routing information, transformations, and all qualities of service for messaging-like reliability, scalability, and availability, etc. Service registry will hold all contracts (wsdl) of services, and it helps developers to locate or discover service during design time or runtime.   • BPEL processor would be useful in orchestrating the services to compose a complex business scenario or process. • Workflow and business rules management are also required to support manual triggering of certain activities within business process. based on the rules setup and also the state machine information. Application, data, and service mediation layer typically forms the overall composite application development framework or SOA Framework.   4.          Business Process Layer: These are typically the intermediate services layer and represent Shared Business Process Services. At Enterprise Level, these services are from Customer Management, Order Management, Billing, Finance, and Asset Management application domains.   5.          Access Layer: This layer consists of portals for Enterprise and provides a single view of Enterprise information management and dashboard services.   6.          Channel Layer: This consists of various devices; applications that form part of extended enterprise; browsers through which users access the applications.   7.          Client Layer: This designates the different types of users accessing the enterprise applications. The type of user typically would be an important factor in determining the level of access to applications.   8.          Vertical pieces like management, monitoring, security, and development cut across all horizontal layers Management and monitoring involves all aspects of SOA-like services, SLAs, and other QoS lifecycle processes for both applications and services surrounding SOA governance.     9.          EA Governance, Reference Architecture, Roadmap, Principles, and Best Practices:   EA Governance is important in terms of providing the overall direction to SOA implementation within the enterprise. This involves board-level involvement, in addition to business and IT executives. At a high level, this involves managing the SOA projects implementation, managing SOA infrastructure, and controlling the entire effort through all fine-tuned IT processes in accordance with COBIT (Control Objectives for Information Technology).   Devising tools and techniques to promote reuse culture, and the SOA way of doing things needs competency centers to be established in addition to training the workforce to take up new roles that are suited to SOA journey.   Conclusions   Reference Architectures can serve as the basis for disparate architecture efforts throughout the organization, even if they use different tools and technologies. Reference architectures provide best practices and approaches in the independent way a vendor deals with technology and standards. Reference Architectures model the abstract architectural elements for an enterprise independent of the technologies, protocols, and products that are used to implement an SOA. Telecom enterprises today are facing significant business and technology challenges due to growing competition, a multitude of services, and convergence. Adopting architectural best practices could go a long way in meeting these challenges. The use of SOA-based architecture for communication to each of the external systems like Billing, CRM, etc., in OSS/BSS system has made the architecture very loosely coupled, with greater flexibility. Any change in the external systems would be absorbed at the Integration Layer without affecting the rest of the ecosystem. The use of a Business Process Management (BPM) tool makes the management and maintenance of the business processes easy, with better performance in terms of lead time, quality, and cost. Since the Architecture is based on standards, it will lower the cost of deploying and managing OSS/BSS applications over their lifecycles.

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