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• APC File Cache not working but user cache is fine

  - by danishgoel

  I have just got a VPS (with cPanel/WHM) to test what gains i could get in my application with using apc file cache AND user cache. So firstly I got the PHP 5.3 compiled in as a DSO (apache module). Then installed APC via PECL through SSH. (First I tried with WHM Module installer, it also had the same problem, so I tried it via ssh) All seemed fine and phpinfo showed apc loaded and enabled. Then I checked with apc.php. All seemed OK But as I started testing my php application, the stats in apc for File Cache Information state: Cached Files 0 ( 0.0 Bytes) Hits 1 Misses 0 Request Rate (hits, misses) 0.00 cache requests/second Hit Rate 0.00 cache requests/second Miss Rate 0.00 cache requests/second Insert Rate 0.00 cache requests/second Cache full count 0 Which meant no PHP files were being cached, even though I had browsed through over 10 PHP files having multiple includes. So there must have been some Cached Files. But the user cache is functioning fine. User Cache Information Cached Variables 0 ( 0.0 Bytes) Hits 1000 Misses 1000 Request Rate (hits, misses) 0.84 cache requests/second Hit Rate 0.42 cache requests/second Miss Rate 0.42 cache requests/second Insert Rate 0.84 cache requests/second Cache full count 0 Its actually from an APC caching test script which tries to retrieve and store 1000 entries and gives me the times. A sort of simple benchmark. Can anyone help me here. Even though apc.cache_by_default = 1, no php files are being cached. This is my apc config Runtime Settings apc.cache_by_default 1 apc.canonicalize 1 apc.coredump_unmap 0 apc.enable_cli 0 apc.enabled 1 apc.file_md5 0 apc.file_update_protection 2 apc.filters apc.gc_ttl 3600 apc.include_once_override 0 apc.lazy_classes 0 apc.lazy_functions 0 apc.max_file_size 1M apc.mmap_file_mask apc.num_files_hint 1000 apc.preload_path apc.report_autofilter 0 apc.rfc1867 0 apc.rfc1867_freq 0 apc.rfc1867_name APC_UPLOAD_PROGRESS apc.rfc1867_prefix upload_ apc.rfc1867_ttl 3600 apc.serializer default apc.shm_segments 1 apc.shm_size 32M apc.slam_defense 1 apc.stat 1 apc.stat_ctime 0 apc.ttl 0 apc.use_request_time 1 apc.user_entries_hint 4096 apc.user_ttl 0 apc.write_lock 1 Also most php files are under 20KB, thus, apc.max_file_size = 1M is not the cause. I have also tried using 'apc_compile_file ' to force some files into opcode cache with no luck. I have also re-installed APC with Debugging enabled, but nothing shows in the error_log I have also tried setting mmap_file_mask to /dev/zero and /tmp/apc.xxxxxx, i have also set /tmp permissions to 777 to no avail Any clue anyone. Update: I have tried following things and none cause APC file cache to populate 1. set apc.enable_cli = 1 AND run a script from cli 2. Set apc.max_file_size = 5M (just in case) 3. switched php handler from dso to FastCGI in WHM (then switched it back to dso as it did not solve the problem) 4. Even tried restarting the container

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• Configured MySQL for SSL , but SLL is still not in use..!

  - by Sunrays

  I configured SSL for MySQL using the following script. #!/bin/bash # mkdir -p /root/abc/ssl_certs cd /root/abc/ssl_certs # echo "--> 1. Create CA cert, private key" openssl genrsa 2048 > ca-key.pem echo "--> 2. Create CA cert, certificate" openssl req -new -x509 -nodes -days 1000 -key ca-key.pem > ca-cert.pem echo "--> 3. Create Server certificate, key" openssl req -newkey rsa:2048 -days 1000 -nodes -keyout server-key.pem > server-req.pem echo "--> 4. Create Server certificate, cert" openssl x509 -req -in server-req.pem -days 1000 -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 > server-cert.pem echo "" echo echo "" echo "--> 5. Create client certificate, key. Use DIFFERENT common name then server!!!!" echo "" openssl req -newkey rsa:2048 -days 1000 -nodes -keyout client-key.pem > client-req.pem echo "6. Create client certificate, cert" openssl x509 -req -in client-req.pem -days 1000 -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 > client-cert.pem exit 0 The following files were created: ca-key.pem ca-cert.pem server-req.pem server-key.pem server-cert.pem client-req.pem client-key.pem client-cert.pem Then I combined server-cert.pem and client-cert.pem into ca.pem (I read in a post to do so..) I created a ssl user in MySQL: GRANT ALL ON *.* to sslsuer@hostname IDENTIFIED BY 'pwd' REQUIRE SSL; Next I added the following in my.cnf [mysqld] ssl-ca = /root/abc/ssl_certs/ca.pem ssl-cert = /root/abc/ssl_certs/server-cert.pem ssl-key = /root/abc/ssl_certs/server-key.pem After restarting the server,I connected to mysql but SSL was still not in use :( mysql -u ssluser -p SSL: Not in use Even the have_ssl parameter was still showing disabled.. :( mysql> show variables like '%ssl%'; +---------------+---------------------------------------------+ | Variable_name | Value | +---------------+---------------------------------------------+ | have_openssl | DISABLED | | have_ssl | DISABLED | | ssl_ca | /root/abc/ssl_certs/ca.pem | | ssl_capath | | | ssl_cert | /root/abc/ssl_certs/server-cert.pem | | ssl_cipher | | | ssl_key | /root/abc/ssl_certs/server-key.pem | +---------------+---------------------------------------------+ Have I missed any step, or whats wrong.. Answers with missed steps in detail will be highly appreciated..

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• SSH to an ubuntu machine using avahi

  - by tensaiji

  I have an ubuntu box that I connect to using avahi. Connecting to that box works fine for all services (I regularly use AFP, SSH and SMB on it) but I've noticed that whenever I connect to it from a mac using SSH (and using the ".local" dns name provided by avahi - eg. "ssh .local") SSH tries to connect using ipv6, which for some reason times out (after two minutes) then it tries ipv4 which connects immediately. I'd like to avoid this timeout, as it's really annoying for me and other users - if SSH tried ipv4 first or if ssh over ipv6 worked then that would solve the problem. But so far I've been unable to get either to work (the best I've managed is to specify the "-4" option to SSH to stop it from trying ipv6 at all). I'm using Ubuntu 10.04. Any solution has to be on the server (not the client) as there are multiple clients connecting. A possible complication might be that my LAN is set up to allow link-local ipv6 addresses only, but I have other servers (using Mac OS) that I can SSH into using ipv6) I suspect that the problem could be solved by either preventing avahi from broadcasting the ipv6 address, or by enabling ssh over ipv6, but so far as I can tell avahi is already configured not to broadcast the ipv6 address and sshd is configured to allow ipv6 connections! Here's my /etc/avahi/avahi-daemon.conf (I don't think I've changed anything from the ubuntu defaults) [server] #host-name=foo #domain-name=local #browse-domains=0pointer.de, zeroconf.org use-ipv4=yes use-ipv6=no #allow-interfaces=eth0 #deny-interfaces=eth1 #check-response-ttl=no #use-iff-running=no #enable-dbus=yes #disallow-other-stacks=no #allow-point-to-point=no [wide-area] enable-wide-area=yes [publish] #disable-publishing=no #disable-user-service-publishing=no #add-service-cookie=no #publish-addresses=yes #publish-hinfo=yes #publish-workstation=yes #publish-domain=yes #publish-dns-servers=192.168.50.1, 192.168.50.2 #publish-resolv-conf-dns-servers=yes #publish-aaaa-on-ipv4=yes #publish-a-on-ipv6=no [reflector] #enable-reflector=no #reflect-ipv=no [rlimits] #rlimit-as= rlimit-core=0 rlimit-data=4194304 rlimit-fsize=0 rlimit-nofile=300 rlimit-stack=4194304 rlimit-nproc=3 and here's my sshd_config (mainly updated to only allow pub/private keys): # What ports, IPs and protocols we listen for Port 22 # Use these options to restrict which interfaces/protocols sshd will bind to #ListenAddress :: #ListenAddress 0.0.0.0 Protocol 2 # HostKeys for protocol version 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key #Privilege Separation is turned on for security UsePrivilegeSeparation yes # Lifetime and size of ephemeral version 1 server key KeyRegenerationInterval 3600 ServerKeyBits 768 # Logging SyslogFacility AUTH LogLevel INFO # Authentication: LoginGraceTime 180 PermitRootLogin no StrictModes yes RSAAuthentication yes PubkeyAuthentication yes #AuthorizedKeysFile %h/.ssh/authorized_keys # Don't read the user's ~/.rhosts and ~/.shosts files IgnoreRhosts yes # For this to work you will also need host keys in /etc/ssh_known_hosts RhostsRSAAuthentication no # similar for protocol version 2 HostbasedAuthentication no # Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication #IgnoreUserKnownHosts yes # To enable empty passwords, change to yes (NOT RECOMMENDED) PermitEmptyPasswords no # Change to yes to enable challenge-response passwords (beware issues with # some PAM modules and threads) ChallengeResponseAuthentication no # Change to no to disable tunnelled clear text passwords PasswordAuthentication no AllowGroups sshusers # Kerberos options #KerberosAuthentication no #KerberosGetAFSToken no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes # GSSAPI options #GSSAPIAuthentication no #GSSAPICleanupCredentials yes X11Forwarding yes X11DisplayOffset 10 PrintMotd no PrintLastLog yes TCPKeepAlive yes #UseLogin no MaxStartups 10:30:60 #Banner /etc/issue.net # Allow client to pass locale environment variables AcceptEnv LANG LC_* Subsystem sftp /usr/lib/openssh/sftp-server UsePAM yes Does anyone have any ideas that I can try, or has experienced anything similar?

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• How can I force all internet traffic over a PPTP VPN but still allow local lan access?

  - by user126715

  I have a server running Linux Mint 12 that I want to keep connected to a PPTP VPN all the time. The VPN server is pretty reliable, but it drops on occasion so I just want to make it so all internet activity is disabled if the VPN connection is broken. I'd also like to figure out a way to restart it automatically, but that's not as big of an issue since this happens pretty rarely. I also want to always be able to connect to the box from my lan, regardless of whether the VPN is up or not. Here's what my ifconfig looks like with the VPN connected properly: eth0 Link encap:Ethernet HWaddr 00:22:15:21:59:9a inet addr:192.168.0.171 Bcast:192.168.0.255 Mask:255.255.255.0 inet6 addr: fe80::222:15ff:fe21:599a/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:37389 errors:0 dropped:0 overruns:0 frame:0 TX packets:29028 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:37781384 (37.7 MB) TX bytes:19281394 (19.2 MB) Interrupt:41 Base address:0x8000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:1446 errors:0 dropped:0 overruns:0 frame:0 TX packets:1446 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:472178 (472.1 KB) TX bytes:472178 (472.1 KB) tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 inet addr:10.10.11.10 P-t-P:10.10.11.9 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1 RX packets:14 errors:0 dropped:0 overruns:0 frame:0 TX packets:23 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:1368 (1.3 KB) TX bytes:1812 (1.8 KB) Here's an iptables script I found elsewhere that seemed to be for the problem I'm trying to solve, but it wound up blocking all access, but I'm not sure what I need to change: #!/bin/bash #Set variables IPT=/sbin/iptables VPN=`ifconfig|perl -nE'/dr:(\S+)/&&say$1'|grep 10.` LAN=192.168.0.0/24 #Flush rules $IPT -F $IPT -X #Default policies and define chains $IPT -P OUTPUT DROP $IPT -P INPUT DROP $IPT -P FORWARD DROP #Allow input from LAN and tun0 ONLY $IPT -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT $IPT -A INPUT -i lo -j ACCEPT $IPT -A INPUT -i tun0 -m conntrack --ctstate NEW -j ACCEPT $IPT -A INPUT -s $LAN -m conntrack --ctstate NEW -j ACCEPT $IPT -A INPUT -j DROP #Allow output from lo and tun0 ONLY $IPT -A OUTPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT $IPT -A OUTPUT -o lo -j ACCEPT $IPT -A OUTPUT -o tun0 -m conntrack --ctstate NEW -j ACCEPT $IPT -A OUTPUT -d $VPN -m conntrack --ctstate NEW -j ACCEPT $IPT -A OUTPUT -j DROP exit 0 Thanks for your help.

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• Nagios shell script cannot be executed

  - by MeinAccount

  I'm trying to monitor GitLab with nagios. I've created the following command definition and shell script but when checking the service I'm receiving the following e-mail. How can I solve this? The file is executable. [...] nagios : 3 incorrect password attempts ; TTY=unknown ; PWD=/ ; USER=git ; COMMAND=/bin/bash -c /var/lib/nagios/custom_plugins/check_gitlab.sh Command definition: define command { command_name custom_check_gitlab command_line /var/lib/nagios/custom_plugins/check_gitlab.sh } Shell script: #! /bin/sh # [...] RAILS_ENV="production" # Script variable names should be lower-case not to conflict with internal /bin/sh variables such as PATH, EDITOR or SHELL. app_root="/home/git/gitlab" app_user="git" unicorn_conf="$app_root/config/unicorn.rb" pid_path="$app_root/tmp/pids" socket_path="$app_root/tmp/sockets" web_server_pid_path="$pid_path/unicorn.pid" sidekiq_pid_path="$pid_path/sidekiq.pid" ### Here ends user configuration ### # Switch to the app_user if it is not he/she who is running the script. if [ "$USER" != "$app_user" ]; then sudo -u "$app_user" -H -i $0 "$@"; exit; fi # Switch to the gitlab path, if it fails exit with an error. if ! cd "$app_root" ; then echo "Failed to cd into $app_root, exiting!"; exit 1 fi ### Init Script functions check_pids(){ if ! mkdir -p "$pid_path"; then echo "Could not create the path $pid_path needed to store the pids." exit 1 fi # If there exists a file which should hold the value of the Unicorn pid: read it. if [ -f "$web_server_pid_path" ]; then wpid=$(cat "$web_server_pid_path") else wpid=0 fi if [ -f "$sidekiq_pid_path" ]; then spid=$(cat "$sidekiq_pid_path") else spid=0 fi } # Checks whether the different parts of the service are already running or not. check_status(){ check_pids # If the web server is running kill -0 $wpid returns true, or rather 0. # Checks of *_status should only check for == 0 or != 0, never anything else. if [ $wpid -ne 0 ]; then kill -0 "$wpid" 2>/dev/null web_status="$?" else web_status="-1" fi if [ $spid -ne 0 ]; then kill -0 "$spid" 2>/dev/null sidekiq_status="$?" else sidekiq_status="-1" fi } check_pids check_status if [ "$web_status" != "0" -a "$sidekiq_status" != "0" ]; then echo "GitLab is not running." exit 2 fi if [ "$web_status" != "0" ]; then printf "The GitLab Unicorn webserver is \033[31mnot running\033[0m.\n" exit 1 fi if [ "$sidekiq_status" != "0" ]; then printf "The GitLab Sidekiq job dispatcher is \033[31mnot running\033[0m.\n" exit 1 fi if [ "$web_status" = "0" -a "$sidekiq_status" = "0" ]; then printf "GitLab and all it's components are \033[32mup and running\033[0m.\n" exit 0 fi

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• Unextending Sharepoint 2007 Web Application from a zone

  - by dunxd

  When our Sharepoint was migrated from Sharepoint 2003 to Sharepoint 2007 (both fully paid versions), the consultants who carried it out extended each web app into two IIS sites/zones (e.g. the original Web App was http://intranet, then http://newintranet and http://intranet would be created for Sharepoint 2007 - each with its own IIS site). The idea was that during the migration period we would set up DNS to point the old url to SP2003 servers and the new one to SP2007, then once the migration was complete, do a DNS change so the SP2007 would recieve the requests to the http://intranet type URLs. Unfortunately the contractors did not tidy up the application extensions and IIS sites after the migration, and for some time both URLs were in use, resulting in many document links pointing to the http://newintranet type URLs. This means I need to maintain these URLs. Due to a rejig of organisation structure we now need to relocate some Sharepoint sites, and I'd like to use the RDA Collaboration Sharepoint URL Redirector feature. However a limitation of this is that it doesn't work for Web Applications which have been extended into multiple zones. So I have a need to tidy up the situation that our consultants left behind. I think the right thing to do is use the "Remove Sharepoint from IIS Web Site" page in Central Admin to remove the zone for the newintranet type sites, and select the option to also delete the IIS site. That should result in having no IIS sites listening for http://newintranet type URLs. Is this the right procedure? Once I have done that I need to set up Sharepoint to receive requests sent to the http://newintranet type URLs so they will continue to work. I am not sure if I should do this: using Alternative Access Mappings or, by adding a host header to the IIS site or, creating a non Sharepoint IIS site for each http://newintranet type URL, and use IIS redirection to forward the requests to the new URL using variables to pass the path to the Sharepoint site. Does anyone have any thoughts on these options, or any other way of achieving this? Sharepoint 2007 is running on Windows 2003 with IIS6. We don't currently have plans/budget to upgrade to Sharepoint 2010.

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• Innodb Queries Slow

  - by user105196

  I have redHat 5.3 (Tikanga) with Mysql 5.0.86 configued with RIAD 10 HW, I run an application inquiries from Mysql/InnoDB and MyIsam tables, the queries are super fast,but some quires on Innodb tables sometime slow down and took more than 1-3 seconds to run and these queries are simple and optimized, this problem occurred just on innodb tables in different time with random queries. Why is this happening only to Innodb tables? the below is the Innodb status and some Mysql variables: show innodb status\G ************* 1. row ************* Status: 120325 10:54:08 INNODB MONITOR OUTPUT Per second averages calculated from the last 19 seconds SEMAPHORES OS WAIT ARRAY INFO: reservation count 22943, signal count 22947 Mutex spin waits 0, rounds 561745, OS waits 7664 RW-shared spins 24427, OS waits 12201; RW-excl spins 1461, OS waits 1277 TRANSACTIONS Trx id counter 0 119069326 Purge done for trx's n:o < 0 119069326 undo n:o < 0 0 History list length 41 Total number of lock structs in row lock hash table 0 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 0 0, not started, process no 29093, OS thread id 1166043456 MySQL thread id 703985, query id 5807220 localhost root show innodb status FILE I/O I/O thread 0 state: waiting for i/o request (insert buffer thread) I/O thread 1 state: waiting for i/o request (log thread) I/O thread 2 state: waiting for i/o request (read thread) I/O thread 3 state: waiting for i/o request (write thread) Pending normal aio reads: 0, aio writes: 0, ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0 Pending flushes (fsync) log: 0; buffer pool: 0 132777 OS file reads, 689086 OS file writes, 252010 OS fsyncs 0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s INSERT BUFFER AND ADAPTIVE HASH INDEX Ibuf: size 1, free list len 366, seg size 368, 62237 inserts, 62237 merged recs, 52881 merges Hash table size 8850487, used cells 3698960, node heap has 7061 buffer(s) 0.00 hash searches/s, 0.00 non-hash searches/s LOG Log sequence number 15 3415398745 Log flushed up to 15 3415398745 Last checkpoint at 15 3415398745 0 pending log writes, 0 pending chkp writes 218214 log i/o's done, 0.00 log i/o's/second BUFFER POOL AND MEMORY Total memory allocated 4798817080; in additional pool allocated 12342784 Buffer pool size 262144 Free buffers 101603 Database pages 153480 Modified db pages 0 Pending reads 0 Pending writes: LRU 0, flush list 0, single page 0 Pages read 151954, created 1526, written 494505 0.00 reads/s, 0.00 creates/s, 0.00 writes/s No buffer pool page gets since the last printout ROW OPERATIONS 0 queries inside InnoDB, 0 queries in queue 1 read views open inside InnoDB Main thread process no. 29093, id 1162049856, state: waiting for server activity Number of rows inserted 77675, updated 85439, deleted 0, read 14377072495 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s END OF INNODB MONITOR OUTPUT 1 row in set, 1 warning (0.02 sec) read_buffer_size = 128M sort_buffer_size = 256M tmp_table_size = 1024M innodb_additional_mem_pool_size = 20M innodb_log_file_size=10M innodb_lock_wait_timeout=100 innodb_buffer_pool_size=4G join_buffer_size = 128M key_buffer_size = 1G can any one help me ?

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• Deployment/provisioning tool for commercial applications (not developed in-house)

  - by mfinni

  I help manage a few hosted commercial applications, and we have a lot of manual processes involved when doing new customer-instance deployments into the shared (multitenant) environment. Allow me to describe the most relevant features, and then we can talk about the tools. We have an application on AIX, that requires dozens of changes to config files (some plain text, some XML) as well as a good number of commands to be run on multiple servers - some to start the new instance, some to restart our shared authentication and reporting engines, etc. The config changes follow templates, of course. The servers in question will also depend on the initial conditions specified by the implementer/deployer - we may choose to deploy a given customer to our servers in Europe, or one set of servers may be active-active whereas a different set of servers is active-passive - in short, there's a lot of complications. We have another application that run on IIS 6 and SQL. The DBAs don't want any automation of the SQL components and that's fine with me, but automating the IIS bit would be great. For a new customer instance, we make a filesystem copy of a template Virtual Directory target named after the new customer, make a new AppPool to match, edit a VirDir template .xml file to replace the filepaths and AppPool names with the new ones, and then make a new VirDir from the modified template XML to point to the new filesystem folder and app pool. For the first case, something like ControlTier or Chef might be good. For the second, the new(ish) Web Deploy from MS would probably do a good job. Has anyone used these tools or others to do something similar for applications? More of a nice-to-have, not a fixed requirement - Has anyone used anything that works on both platforms? I'm looking for something free, because the official word is that within a year, we will have whatever HP has renamed the OpsWare suite, which should be able to do stuff like this. Edit - based on someone's suggestion, looking at CFengine for the AIX application, it doesn't seem to address my pain. The problem isn't keeping a given config synced across dozens of servers, we have rsync for that. The problem is that onboarding a new customer instance touches dozens of files, putting pieces of the same or similar information into them - some are new stanzas in existing files, some are new files, and some are new directories. This is a several-hours-long process that is also error-prone because it's mostly done by hand. I guess I'm looking for config-file generation and management. I have built a small Perl script to do something similar for a much smaller case - it binds a CSV file into variables, and then does a copy-and-search-and-replace from a set of template config files. I could probably do the same here.

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• Moving default web site to another drive

  - by Chadworthington

  I set the default location from c:\inetpub\wwwroot to d:\inetpub\wwwroot but when I access my .NET 4.0 site get this error: Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately. Parser Error Message: Unrecognized attribute 'targetFramework'. Note that attribute names are case-sensitive. Source Error: Line 105: Set explicit="true" to force declaration of all variables. Line 106: --> Line 107: <compilation debug="true" strict="true" explicit="true" targetFramework="4.0"> Line 108: <assemblies> Line 109: <add assembly="System.Web.Extensions.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> When I try to Manage the Basic Settings on the Site and click the "Test Settings" button, I see that I have a problem under "authorization:" The server is configured to use pass-through authentication with a built-in account to access the specified physical path. However, IIS Manager cannot verify whether the built-in account has access. Make sure that the application pool identity has Read access to the physical path. If this server is joined to a domain, and the application pool identity is NetworkService or LocalSystem, verify that <domain>\<computer_name>$ has Read access to the physical path. Then test these settings again. 1) Do I need to grant rights to IIS to the new folder? Which user? I thought it was something like IIS_USER or something similar but I cannot determine the correct name of the user. 2) Also, do I need to set the default version of the framework somewhere at the Default Site level or at the Virtual folder level? How is this done in IIS6, I am used to IIS5 or whatever came with XP Pro. 3) My original site had a subfolder under wwwroot called "aspnet_client." How was this cleated? I manually copied it to the corresponding new location. My app was using seperate ASP specific databases for storing session state and role info, if that is relevant. Thanks

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• Automating silent software deployments on Solaris 10

  - by datSilencer

  Hello everyone. Essentially, the question I'd like to ask is related to the automation of software package deployments on Solaris 10. Specifically, I have a set of software components in tar files that run as daemon processes after being extracted and configured in the host environment. Pretty much like any server side software package out there, I need to ensure that a list of prerequisites are met before extracting and running the software. For example: Checking that certain users exists, and they are associated with one or many user groups. If not, then create them and their group associations. Checking that target application folders exist and if not, then create them with preconfigured path values defined when the package was assembled. Checking that such folders have the appropriate access control level and ownership for a certain user. If not, then set them. Checking that a set of environment variables are defined in /etc/profile, pointed to predefined path locations, added to the general $PATH environment variable, and finally exported into the user's environment. Other files include /etc/services and /etc/system. Obviously, doing this for many boxes (the goal in question) by hand can be slow and error prone. I believe a better alternative is to somehow automate this process. So far I have thought about the following options, and discarded them for one reason or another. 1) Traditional shell scripts. I've only troubleshooted these before, and I don't really have much experience with them. These would be my last resort. 2) Python scripts using the pexpect library for analyzing system command output. This was my initial choice since the target Solaris environments have it installed. However, I want to make sure that I'm not reinveting the wheel again :P. 3) Ant or Gradle scripts. They may be an option since the boxes also have java 1.5 enabled, and the fileset abstractions can be very useful. However, they may fall short when dealing with user and folder permissions checking/setting. It seems obvious to me that I'm not the first person in this situation, but I don't seem to find a utility framework geared towards this purpose. Please let me know if there's a better way to accomplish this. I thank you for your time and help.

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• Script to check a shared Exchange calendar and then email detail

  - by SJN

  We're running Server and Exchange 2003 here. There's a shared calendar which HR keep up-to-date detailing staff who are on leave. I'm looking for a VB Script (or alternate) which will extract the "appointment" titles of each item for the current day and then email the detail to a mail group, in doing so notifying the group with regard to which staff are on leave for the day. The resulting email body should be: Staff on leave today: Mike Davis James Stead @Paul Robichaux - ADO is the way I went for this in the end, here are the key component for those interested: Dim Rs, Conn, Url, Username, Password, Recipient Set Rs = CreateObject("ADODB.Recordset") Set Conn = CreateObject("ADODB.Connection") 'Configurable variables Username = "Domain\username" ' AD domain\username Password = "password" ' AD password Url = "file://./backofficestorage/domain.com/MBX/username/Calendar" 'path to user's mailbox and folder Recipient = "[email protected]" Conn.Provider = "ExOLEDB.DataSource" Conn.Open Url, Username, Password Set Rs.ActiveConnection = Conn Rs.Source = "SELECT ""DAV:href"", " & _ " ""urn:schemas:httpmail:subject"", " & _ " ""urn:schemas:calendar:dtstart"", " & _ " ""urn:schemas:calendar:dtend"" " & _ "FROM scope('shallow traversal of """"') " Rs.Open Rs.MoveFirst strOutput = "" Do Until Rs.EOF If DateDiff("s", Rs.Fields("urn:schemas:calendar:dtstart"), date) >= 0 And DateDiff("s", Rs.Fields("urn:schemas:calendar:dtend"), date) < 0 Then strOutput = strOutput & "<p><font size='2' color='black' face='verdana'><b>" & Rs.Fields("urn:schemas:httpmail:subject") & "</b><br />" & vbCrLf strOutput = strOutput & "<b>From: </b>" & Rs.Fields("urn:schemas:calendar:dtstart") & vbCrLf strOutput = strOutput & "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<b>To: </b>" & Rs.Fields("urn:schemas:calendar:dtend") & "<br /><br />" & vbCrLf End If Rs.MoveNext Loop Conn.Close Set Conn = Nothing Set Rec = Nothing After that, you can do what you like with srtOutput, I happened to use CDO to send an email: Set objMessage = CreateObject("CDO.Message") objMessage.Subject = "Subject" objMessage.From = "[email protected]" objMessage.To = Recipient objMessage.HTMLBody = strOutput objMessage.Send S

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• Why did Intel drop the Itanium?

  - by Cole Johnson

  I was reading up on the history of the computer and I came along the IA-64 (Itanium) processors. They sounded really interesting and I was confused as to why Intel would decide to drop them. The ability to choose explicitly what 2 instructions you wanted to run in that cycle is a great idea, especially when writing your program in assembly, for example, a faster bootloader. The hundreds of registers should be convincing for any assembly programmer. You could essentially store all the functions variables in the registers if it doesn't call any other ones. The ability to do instructions like this: (qp) xor r1 = r2, r3 ; r1 = r2 XOR r3 (qp) xor r1 = (imm8), r3 ; r1 = (imm8) XOR r3 versus having to do: ; eax = r1 ; ebx = r2 ; ecx = r3 mov eax, ebx ; first put r2 into r1 xor eax, ecx ; then set r1 equivalent to r2 XOR r3 or ; SAME mov eax, (imm32) ; first put (imm32) into r1 xor eax, ecx ; then set r1 equivalent to (imm32) XOR r3 I heard it was because of no backwards x86 comparability, but couldn't thy be fixed by just adding the Pentium circuitry to it and just add a processor flag that would switch it to Itanium mode (like switching to Protected or Long mode) All the great things about it would have surly put them a giant leap ahead of AMD. Any ideas? Sadly this means you will need a very advanced compiler to do this. Or even one per specific model of the CPU. (E.g. a newer version of the Itanium with an extra feature would require different compiler). When I was working on a WinForms (target only had .NET 2.0) project in Visual Studio 2010, I had a compile target of IA-64. That means that there is a .NET runtime that was able to be compiled for IA-64 and a .NET runtime means Windows. Plus, Hamilton's answer mentions Windows NT. Having a full blown OS like Windows NT means that there is a compiler capable of generating IA-64 machine code.

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• Troubleshooting Network Speeds -- The Age Old Inquiry

  - by John K

  I'm looking for help with what I'm sure is an age old question. I've found myself in a situation of yearning to understand network throughput more clearly, but I can't seem to find information that makes it "click" We have a few servers distributed geographically, running various versions of Windows. Assuming we always use one host (a desktop) as the source, when copying data from that host to other servers across the country, we see a high variance in speed. In some cases, we can copy data at 12MB/s consistently, in others, we're seeing 0.8 MB/s. It should be noted, after testing 8 destinations, we always seem to be at either 0.6-0.8MB/s or 11-12 MB/s. In the building we're primarily concerned with, we have an OC-3 connection to our ISP. I know there are a lot of variables at play, but I guess I was hoping the experts here could help answer a few basic questions to help bolster my understanding. 1.) For older machines, running Windows XP, server 2003, etc, with a 100Mbps Ethernet card and 72 ms typical latency, does 0.8 MB/s sound at all reasonable? Or do you think that slow enough to indicate a problem? 2.) The classic "mathematical fastest speed" of "throughput = TCP window / latency," is, in our case, calculated to 0.8 MB/s (64Kb / 72 ms). My understanding is that is an upper bounds; that you would never expect to reach (due to overhead) let alone surpass that speed. In some cases though, we're seeing speeds of 12.3 MB/s. There are Steelhead accelerators scattered around the network, could those account for such a higher transfer rate? 3.) It's been suggested that the use SMB vs. SMB2 could explain the differences in speed. Indeed, as expected, packet captures show both being used depending on the OS versions in play, as we would expect. I understand what determines SMB2 being used or not, but I'm curious to know what kind of performance gain you can expect with SMB2. My problem simply seems to be a lack of experience, and more importantly, perspective, in terms of what are and are not reasonable network speeds. Could anyone help impart come context/perspective?

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• How to loop through all illustrator files in a folder (CS6)

  - by Julian

  I have written some JavaScript to save .ai files to two separate locations with different resolutions, one of them being cropped to a reduced size art board. (Courtesy of John Otterud / Articmill for the main part). There are other variables in the script that I am not using at present but I want to leave the functionality there for a later date/additional layers to export/other resolutions etc. I can't get it to loop through all files in a folder. I cannot find the script that works - or insert it at the right place. I can get as far a selecting the folder and I suppose creating an array but after that what next? This is the create array part of the script - // JavaScript Document //Set up vairaibles var destDoc, sourceDoc, sourceFolder, newLayer; // Select the source folder. sourceFolder = Folder.selectDialog('Select the folder with Illustrator files that you want to mere into one', '~'); destDoc = app.documents.add(); // If a valid folder is selected if (sourceFolder != null) { files = new Array(); // Get all files matching the pattern files = sourceFolder.getFiles(); I have inserted this at the beginning of the main script (probably where I am going wrong because I can select the folder but then nothing more) #target illustrator var docRef = app.activeDocument; with (docRef) { if (layers[i].name = 'HEADER') { layers[i].name = '#'+ activeDocument.name; save() } } // *** Export Layers as PNG files (in multiple resolutions) *** var subFolderName = "For_PLMA"; var subFolderTwoName = "For_VLP"; var saveInMultipleResolutions = true; // ... // Note: only use one character! var exportLayersStartingWith = "%"; var exportLayersWithArtboardClippingStartingWith = "#"; // ... var normalResolutionFileAppend = "_VLP"; var highResolutionFileAppend = "_PLMA"; // ... var normalResolutionScale = 100; var highResolutionScale = 200; var veryhighResolutionScale = 300; // *** Start of script *** var doc = app.activeDocument; // Make sure we have saved the document if (doc.path != "") { Then the rest of the export script runs on from there.

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• LWJGL - Eclipse error [on hold]

  - by Zarkopafilis

  When I try to run my lwjgl project, an error pops . Here is the log file: # A fatal error has been detected by the Java Runtime Environment: # EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d8fcc0a, pid=5612, tid=900 # JRE version: 6.0_16-b01 Java VM: Java HotSpot(TM) Client VM (14.2-b01 mixed mode windows-x86 ) Problematic frame: V [jvm.dll+0xfcc0a] # If you would like to submit a bug report, please visit: http://java.sun.com/webapps/bugreport/crash.jsp # --------------- T H R E A D --------------- Current thread (0x016b9000): JavaThread "main" [_thread_in_vm, id=900, stack(0x00160000,0x001b0000)] siginfo: ExceptionCode=0xc0000005, reading address 0x00000000 Registers: EAX=0x00000000, EBX=0x00000000, ECX=0x00000006, EDX=0x00000000 ESP=0x001af4d4, EBP=0x001af524, ESI=0x016b9000, EDI=0x016b9110 EIP=0x6d8fcc0a, EFLAGS=0x00010246 Top of Stack: (sp=0x001af4d4) 0x001af4d4: 6da44bd8 016b9110 00000000 001af668 0x001af4e4: ffffffff 22200000 001af620 76ec39c2 0x001af4f4: 001af524 6d801086 0000000b 001afd34 0x001af504: 016b9000 016dd990 016b9000 00000000 0x001af514: 001af5f4 6d9ee000 6d9ef2f0 ffffffff 0x001af524: 001af58c 10008c85 016b9110 00000000 0x001af534: 00000000 000a0554 00000000 00000024 0x001af544: 00000000 00000000 001af6ac 00000000 Instructions: (pc=0x6d8fcc0a) 0x6d8fcbfa: e8 e8 d0 1d 08 00 8b 45 10 c7 45 d8 0b 00 00 00 0x6d8fcc0a: 8b 00 8b 48 08 0f b7 51 26 8b 40 0c 8b 4c 90 20 Stack: [0x00160000,0x001b0000], sp=0x001af4d4, free space=317k Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code) V [jvm.dll+0xfcc0a] C [lwjgl.dll+0x8c85] C [USER32.dll+0x18876] C [USER32.dll+0x170f4] C [USER32.dll+0x1119e] C [ntdll.dll+0x460ce] C [USER32.dll+0x10e29] C [USER32.dll+0x10e84] C [lwjgl.dll+0x1cf0] j org.lwjgl.opengl.WindowsDisplay.createWindow(Lorg/lwjgl/opengl/DrawableLWJGL;Lorg/lwjgl/opengl/DisplayMode;Ljava/awt/Canvas;II)V+102 j org.lwjgl.opengl.Display.createWindow()V+71 j org.lwjgl.opengl.Display.create(Lorg/lwjgl/opengl/PixelFormat;Lorg/lwjgl/opengl/Drawable;Lorg/lwjgl/opengl/ContextAttribs;)V+72 j org.lwjgl.opengl.Display.create(Lorg/lwjgl/opengl/PixelFormat;)V+12 j org.lwjgl.opengl.Display.create()V+7 j zarkopafilis.koding.io.javafx.Main.main([Ljava/lang/String;)V+16 v ~StubRoutines::call_stub V [jvm.dll+0xecf9c] V [jvm.dll+0x1741e1] V [jvm.dll+0xed01d] V [jvm.dll+0xf5be5] V [jvm.dll+0xfd83d] C [javaw.exe+0x2155] C [javaw.exe+0x833e] C [kernel32.dll+0x51154] C [ntdll.dll+0x5b2b9] C [ntdll.dll+0x5b28c] Java frames: (J=compiled Java code, j=interpreted, Vv=VM code) j org.lwjgl.opengl.WindowsDisplay.nCreateWindow(IIIIZZJ)J+0 j org.lwjgl.opengl.WindowsDisplay.createWindow(Lorg/lwjgl/opengl/DrawableLWJGL;Lorg/lwjgl/opengl/DisplayMode;Ljava/awt/Canvas;II)V+102 j org.lwjgl.opengl.Display.createWindow()V+71 j org.lwjgl.opengl.Display.create(Lorg/lwjgl/opengl/PixelFormat;Lorg/lwjgl/opengl/Drawable;Lorg/lwjgl/opengl/ContextAttribs;)V+72 j org.lwjgl.opengl.Display.create(Lorg/lwjgl/opengl/PixelFormat;)V+12 j org.lwjgl.opengl.Display.create()V+7 j zarkopafilis.koding.io.javafx.Main.main([Ljava/lang/String;)V+16 v ~StubRoutines::call_stub --------------- P R O C E S S --------------- Java Threads: ( = current thread ) 0x0179a400 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=4460, stack(0x0b900000,0x0b950000)] 0x01795400 JavaThread "CompilerThread0" daemon [_thread_blocked, id=5264, stack(0x0b8b0000,0x0b900000)] 0x01790c00 JavaThread "Attach Listener" daemon [_thread_blocked, id=6080, stack(0x0b860000,0x0b8b0000)] 0x01786400 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=1204, stack(0x0b810000,0x0b860000)] 0x01759c00 JavaThread "Finalizer" daemon [_thread_blocked, id=5772, stack(0x0b7c0000,0x0b810000)] 0x01755000 JavaThread "Reference Handler" daemon [_thread_blocked, id=4696, stack(0x01640000,0x01690000)] =0x016b9000 JavaThread "main" [_thread_in_vm, id=900, stack(0x00160000,0x001b0000)] Other Threads: 0x01751c00 VMThread [stack: 0x015f0000,0x01640000] [id=4052] 0x0179c800 WatcherThread [stack: 0x0b950000,0x0b9a0000] [id=3340] VM state:not at safepoint (normal execution) VM Mutex/Monitor currently owned by a thread: None Heap def new generation total 960K, used 816K [0x037c0000, 0x038c0000, 0x03ca0000) eden space 896K, 91% used [0x037c0000, 0x0388c2c0, 0x038a0000) from space 64K, 0% used [0x038a0000, 0x038a0000, 0x038b0000) to space 64K, 0% used [0x038b0000, 0x038b0000, 0x038c0000) tenured generation total 4096K, used 0K [0x03ca0000, 0x040a0000, 0x077c0000) the space 4096K, 0% used [0x03ca0000, 0x03ca0000, 0x03ca0200, 0x040a0000) compacting perm gen total 12288K, used 2143K [0x077c0000, 0x083c0000, 0x0b7c0000) the space 12288K, 17% used [0x077c0000, 0x079d7e38, 0x079d8000, 0x083c0000) No shared spaces configured. Dynamic libraries: 0x00400000 - 0x00424000 C:\Program Files\Java\jre6\bin\javaw.exe 0x77550000 - 0x7768e000 C:\Windows\SYSTEM32\ntdll.dll 0x75a80000 - 0x75b54000 C:\Windows\system32\kernel32.dll 0x758d0000 - 0x7591b000 C:\Windows\system32\KERNELBASE.dll 0x759e0000 - 0x75a80000 C:\Windows\system32\ADVAPI32.dll 0x76070000 - 0x7611c000 C:\Windows\system32\msvcrt.dll 0x77250000 - 0x77269000 C:\Windows\SYSTEM32\sechost.dll 0x771a0000 - 0x77241000 C:\Windows\system32\RPCRT4.dll 0x76eb0000 - 0x76f79000 C:\Windows\system32\USER32.dll 0x76e60000 - 0x76eae000 C:\Windows\system32\GDI32.dll 0x77770000 - 0x7777a000 C:\Windows\system32\LPK.dll 0x75fd0000 - 0x7606e000 C:\Windows\system32\USP10.dll 0x770b0000 - 0x770cf000 C:\Windows\system32\IMM32.DLL 0x770d0000 - 0x7719c000 C:\Windows\system32\MSCTF.dll 0x7c340000 - 0x7c396000 C:\Program Files\Java\jre6\bin\msvcr71.dll 0x6d800000 - 0x6da8b000 C:\Program Files\Java\jre6\bin\client\jvm.dll 0x73a00000 - 0x73a32000 C:\Windows\system32\WINMM.dll 0x75610000 - 0x7565b000 C:\Windows\system32\apphelp.dll 0x6d7b0000 - 0x6d7bc000 C:\Program Files\Java\jre6\bin\verify.dll 0x6d330000 - 0x6d34f000 C:\Program Files\Java\jre6\bin\java.dll 0x6d290000 - 0x6d298000 C:\Program Files\Java\jre6\bin\hpi.dll 0x776e0000 - 0x776e5000 C:\Windows\system32\PSAPI.DLL 0x6d7f0000 - 0x6d7ff000 C:\Program Files\Java\jre6\bin\zip.dll 0x10000000 - 0x1004c000 C:\Users\theo\Desktop\workspace\JavaFX1\lib\natives\windows\lwjgl.dll 0x5d170000 - 0x5d238000 C:\Windows\system32\OPENGL32.dll 0x6e7b0000 - 0x6e7d2000 C:\Windows\system32\GLU32.dll 0x70620000 - 0x70707000 C:\Windows\system32\DDRAW.dll 0x70610000 - 0x70616000 C:\Windows\system32\DCIMAN32.dll 0x75b60000 - 0x75cfd000 C:\Windows\system32\SETUPAPI.dll 0x759b0000 - 0x759d7000 C:\Windows\system32\CFGMGR32.dll 0x76d70000 - 0x76dff000 C:\Windows\system32\OLEAUT32.dll 0x75db0000 - 0x75f0c000 C:\Windows\system32\ole32.dll 0x758b0000 - 0x758c2000 C:\Windows\system32\DEVOBJ.dll 0x74060000 - 0x74073000 C:\Windows\system32\dwmapi.dll 0x74b60000 - 0x74b69000 C:\Windows\system32\VERSION.dll 0x745f0000 - 0x7478e000 C:\Windows\WinSxS\x86_microsoft.windows.common-controls_6595b64144ccf1df_6.0.7600.16661_none_420fe3fa2b8113bd\COMCTL32.dll 0x75d50000 - 0x75da7000 C:\Windows\system32\SHLWAPI.dll 0x74370000 - 0x743b0000 C:\Windows\system32\uxtheme.dll 0x22200000 - 0x22206000 C:\Program Files\ESET\ESET Smart Security\eplgHooks.dll VM Arguments: jvm_args: -Djava.library.path=C:\Users\theo\Desktop\workspace\JavaFX1\lib\natives\windows -Dfile.encoding=Cp1253 java_command: zarkopafilis.koding.io.javafx.Main Launcher Type: SUN_STANDARD Environment Variables: PATH=C:/Program Files/Java/jre6/bin/client;C:/Program Files/Java/jre6/bin;C:/Program Files/Java/jre6/lib/i386;C:\Perl\site\bin;C:\Perl\bin;C:\Ruby200\bin;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Windows Live\Shared;C:\Users\theo\Desktop\eclipse; USERNAME=theo OS=Windows_NT PROCESSOR_IDENTIFIER=x86 Family 6 Model 37 Stepping 5, GenuineIntel --------------- S Y S T E M --------------- OS: Windows 7 Build 7600 CPU:total 4 (8 cores per cpu, 2 threads per core) family 6 model 37 stepping 5, cmov, cx8, fxsr, mmx, sse, sse2, sse3, ssse3, sse4.1, sse4.2, ht Memory: 4k page, physical 2097151k(1257972k free), swap 4194303k(4194303k free) vm_info: Java HotSpot(TM) Client VM (14.2-b01) for windows-x86 JRE (1.6.0_16-b01), built on Jul 31 2009 11:26:58 by "java_re" with MS VC++ 7.1 time: Wed Oct 23 22:00:12 2013 elapsed time: 0 seconds Code: Display.setDisplayMode(new DisplayMode(800,600)); Display.create();//Error here I am using JDK 6

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• Capturing and Transforming ASP.NET Output with Response.Filter

  - by Rick Strahl

  During one of my Handlers and Modules session at DevConnections this week one of the attendees asked a question that I didn’t have an immediate answer for. Basically he wanted to capture response output completely and then apply some filtering to the output – effectively injecting some additional content into the page AFTER the page had completely rendered. Specifically the output should be captured from anywhere – not just a page and have this code injected into the page. Some time ago I posted some code that allows you to capture ASP.NET Page output by overriding the Render() method, capturing the HtmlTextWriter() and reading its content, modifying the rendered data as text then writing it back out. I’ve actually used this approach on a few occasions and it works fine for ASP.NET pages. But this obviously won’t work outside of the Page class environment and it’s not really generic – you have to create a custom page class in order to handle the output capture. [updated 11/16/2009 – updated ResponseFilterStream implementation and a few additional notes based on comments] Enter Response.Filter However, ASP.NET includes a Response.Filter which can be used – well to filter output. Basically Response.Filter is a stream through which the OutputStream is piped back to the Web Server (indirectly). As content is written into the Response object, the filter stream receives the appropriate Stream commands like Write, Flush and Close as well as read operations although for a Response.Filter that’s uncommon to be hit. The Response.Filter can be programmatically replaced at runtime which allows you to effectively intercept all output generation that runs through ASP.NET. A common Example: Dynamic GZip Encoding A rather common use of Response.Filter hooking up code based, dynamic  GZip compression for requests which is dead simple by applying a GZipStream (or DeflateStream) to Response.Filter. The following generic routines can be used very easily to detect GZip capability of the client and compress response output with a single line of code and a couple of library helper routines: WebUtils.GZipEncodePage(); which is handled with a few lines of reusable code and a couple of static helper methods: /// <summary> ///Sets up the current page or handler to use GZip through a Response.Filter ///IMPORTANT:  ///You have to call this method before any output is generated! /// </summary> public static void GZipEncodePage() {     HttpResponse Response = HttpContext.Current.Response;     if(IsGZipSupported())     {         stringAcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"];         if(AcceptEncoding.Contains("deflate"))         {             Response.Filter = newSystem.IO.Compression.DeflateStream(Response.Filter,                                        System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "deflate");         }         else        {             Response.Filter = newSystem.IO.Compression.GZipStream(Response.Filter,                                       System.IO.Compression.CompressionMode.Compress);             Response.AppendHeader("Content-Encoding", "gzip");                            }     }     // Allow proxy servers to cache encoded and unencoded versions separately    Response.AppendHeader("Vary", "Content-Encoding"); } /// <summary> /// Determines if GZip is supported /// </summary> /// <returns></returns> public static bool IsGZipSupported() { string AcceptEncoding = HttpContext.Current.Request.Headers["Accept-Encoding"]; if (!string.IsNullOrEmpty(AcceptEncoding) && (AcceptEncoding.Contains("gzip") || AcceptEncoding.Contains("deflate"))) return true; return false; } GZipStream and DeflateStream are streams that are assigned to Response.Filter and by doing so apply the appropriate compression on the active Response. Response.Filter content is chunked So to implement a Response.Filter effectively requires only that you implement a custom stream and handle the Write() method to capture Response output as it’s written. At first blush this seems very simple – you capture the output in Write, transform it and write out the transformed content in one pass. And that indeed works for small amounts of content. But you see, the problem is that output is written in small buffer chunks (a little less than 16k it appears) rather than just a single Write() statement into the stream, which makes perfect sense for ASP.NET to stream data back to IIS in smaller chunks to minimize memory usage en route. Unfortunately this also makes it a more difficult to implement any filtering routines since you don’t directly get access to all of the response content which is problematic especially if those filtering routines require you to look at the ENTIRE response in order to transform or capture the output as is needed for the solution the gentleman in my session asked for. So in order to address this a slightly different approach is required that basically captures all the Write() buffers passed into a cached stream and then making the stream available only when it’s complete and ready to be flushed. As I was thinking about the implementation I also started thinking about the few instances when I’ve used Response.Filter implementations. Each time I had to create a new Stream subclass and create my custom functionality but in the end each implementation did the same thing – capturing output and transforming it. I thought there should be an easier way to do this by creating a re-usable Stream class that can handle stream transformations that are common to Response.Filter implementations. Creating a semi-generic Response Filter Stream Class What I ended up with is a ResponseFilterStream class that provides a handful of Events that allow you to capture and/or transform Response content. The class implements a subclass of Stream and then overrides Write() and Flush() to handle capturing and transformation operations. By exposing events it’s easy to hook up capture or transformation operations via single focused methods. ResponseFilterStream exposes the following events: CaptureStream, CaptureString Captures the output only and provides either a MemoryStream or String with the final page output. Capture is hooked to the Flush() operation of the stream. TransformStream, TransformString Allows you to transform the complete response output with events that receive a MemoryStream or String respectively and can you modify the output then return it back as a return value. The transformed output is then written back out in a single chunk to the response output stream. These events capture all output internally first then write the entire buffer into the response. TransformWrite, TransformWriteString Allows you to transform the Response data as it is written in its original chunk size in the Stream’s Write() method. Unlike TransformStream/TransformString which operate on the complete output, these events only see the current chunk of data written. This is more efficient as there’s no caching involved, but can cause problems due to searched content splitting over multiple chunks. Using this implementation, creating a custom Response.Filter transformation becomes as simple as the following code. To hook up the Response.Filter using the MemoryStream version event: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformStream += filter_TransformStream; Response.Filter = filter; and the event handler to do the transformation: MemoryStream filter_TransformStream(MemoryStream ms) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = encoding.GetString(ms.ToArray()); output = FixPaths(output); ms = new MemoryStream(output.Length); byte[] buffer = encoding.GetBytes(output); ms.Write(buffer,0,buffer.Length); return ms; } private string FixPaths(string output) { string path = HttpContext.Current.Request.ApplicationPath; // override root path wonkiness if (path == "/") path = ""; output = output.Replace("\"~/", "\"" + path + "/").Replace("'~/", "'" + path + "/"); return output; } The idea of the event handler is that you can do whatever you want to the stream and return back a stream – either the same one that’s been modified or a brand new one – which is then sent back to as the final response. The above code can be simplified even more by using the string version events which handle the stream to string conversions for you: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; and the event handler to do the transformation calling the same FixPaths method shown above: string filter_TransformString(string output) { return FixPaths(output); } The events for capturing output and capturing and transforming chunks work in a very similar way. By using events to handle the transformations ResponseFilterStream becomes a reusable component and we don’t have to create a new stream class or subclass an existing Stream based classed. By the way, the example used here is kind of a cool trick which transforms “~/” expressions inside of the final generated HTML output – even in plain HTML controls not HTML controls – and transforms them into the appropriate application relative path in the same way that ResolveUrl would do. So you can write plain old HTML like this: <a href=”~/default.aspx”>Home</a>  and have it turned into: <a href=”/myVirtual/default.aspx”>Home</a>  without having to use an ASP.NET control like Hyperlink or Image or having to constantly use: <img src=”<%= ResolveUrl(“~/images/home.gif”) %>” /> in MVC applications (which frankly is one of the most annoying things about MVC especially given the path hell that extension-less and endpoint-less URLs impose). I can’t take credit for this idea. While discussing the Response.Filter issues on Twitter a hint from Dylan Beattie who pointed me at one of his examples which does something similar. I thought the idea was cool enough to use an example for future demos of Response.Filter functionality in ASP.NET next I time I do the Modules and Handlers talk (which was great fun BTW). How practical this is is debatable however since there’s definitely some overhead to using a Response.Filter in general and especially on one that caches the output and the re-writes it later. Make sure to test for performance anytime you use Response.Filter hookup and make sure it' doesn’t end up killing perf on you. You’ve been warned :-}. How does ResponseFilterStream work? The big win of this implementation IMHO is that it’s a reusable  component – so for implementation there’s no new class, no subclassing – you simply attach to an event to implement an event handler method with a straight forward signature to retrieve the stream or string you’re interested in. The implementation is based on a subclass of Stream as is required in order to handle the Response.Filter requirements. What’s different than other implementations I’ve seen in various places is that it supports capturing output as a whole to allow retrieving the full response output for capture or modification. The exception are the TransformWrite and TransformWrite events which operate only active chunk of data written by the Response. For captured output, the Write() method captures output into an internal MemoryStream that is cached until writing is complete. So Write() is called when ASP.NET writes to the Response stream, but the filter doesn’t pass on the Write immediately to the filter’s internal stream. The data is cached and only when the Flush() method is called to finalize the Stream’s output do we actually send the cached stream off for transformation (if the events are hooked up) and THEN finally write out the returned content in one big chunk. Here’s the implementation of ResponseFilterStream: /// <summary> /// A semi-generic Stream implementation for Response.Filter with /// an event interface for handling Content transformations via /// Stream or String. /// <remarks> /// Use with care for large output as this implementation copies /// the output into a memory stream and so increases memory usage. /// </remarks> /// </summary> public class ResponseFilterStream : Stream { /// <summary> /// The original stream /// </summary> Stream _stream; /// <summary> /// Current position in the original stream /// </summary> long _position; /// <summary> /// Stream that original content is read into /// and then passed to TransformStream function /// </summary> MemoryStream _cacheStream = new MemoryStream(5000); /// <summary> /// Internal pointer that that keeps track of the size /// of the cacheStream /// </summary> int _cachePointer = 0; /// <summary> /// /// </summary> /// <param name="responseStream"></param> public ResponseFilterStream(Stream responseStream) { _stream = responseStream; } /// <summary> /// Determines whether the stream is captured /// </summary> private bool IsCaptured { get { if (CaptureStream != null || CaptureString != null || TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Determines whether the Write method is outputting data immediately /// or delaying output until Flush() is fired. /// </summary> private bool IsOutputDelayed { get { if (TransformStream != null || TransformString != null) return true; return false; } } /// <summary> /// Event that captures Response output and makes it available /// as a MemoryStream instance. Output is captured but won't /// affect Response output. /// </summary> public event Action<MemoryStream> CaptureStream; /// <summary> /// Event that captures Response output and makes it available /// as a string. Output is captured but won't affect Response output. /// </summary> public event Action<string> CaptureString; /// <summary> /// Event that allows you transform the stream as each chunk of /// the output is written in the Write() operation of the stream. /// This means that that it's possible/likely that the input /// buffer will not contain the full response output but only /// one of potentially many chunks. /// /// This event is called as part of the filter stream's Write() /// operation. /// </summary> public event Func<byte[], byte[]> TransformWrite; /// <summary> /// Event that allows you to transform the response stream as /// each chunk of bytep[] output is written during the stream's write /// operation. This means it's possibly/likely that the string /// passed to the handler only contains a portion of the full /// output. Typical buffer chunks are around 16k a piece. /// /// This event is called as part of the stream's Write operation. /// </summary> public event Func<string, string> TransformWriteString; /// <summary> /// This event allows capturing and transformation of the entire /// output stream by caching all write operations and delaying final /// response output until Flush() is called on the stream. /// </summary> public event Func<MemoryStream, MemoryStream> TransformStream; /// <summary> /// Event that can be hooked up to handle Response.Filter /// Transformation. Passed a string that you can modify and /// return back as a return value. The modified content /// will become the final output. /// </summary> public event Func<string, string> TransformString; protected virtual void OnCaptureStream(MemoryStream ms) { if (CaptureStream != null) CaptureStream(ms); } private void OnCaptureStringInternal(MemoryStream ms) { if (CaptureString != null) { string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); OnCaptureString(content); } } protected virtual void OnCaptureString(string output) { if (CaptureString != null) CaptureString(output); } protected virtual byte[] OnTransformWrite(byte[] buffer) { if (TransformWrite != null) return TransformWrite(buffer); return buffer; } private byte[] OnTransformWriteStringInternal(byte[] buffer) { Encoding encoding = HttpContext.Current.Response.ContentEncoding; string output = OnTransformWriteString(encoding.GetString(buffer)); return encoding.GetBytes(output); } private string OnTransformWriteString(string value) { if (TransformWriteString != null) return TransformWriteString(value); return value; } protected virtual MemoryStream OnTransformCompleteStream(MemoryStream ms) { if (TransformStream != null) return TransformStream(ms); return ms; } /// <summary> /// Allows transforming of strings /// /// Note this handler is internal and not meant to be overridden /// as the TransformString Event has to be hooked up in order /// for this handler to even fire to avoid the overhead of string /// conversion on every pass through. /// </summary> /// <param name="responseText"></param> /// <returns></returns> private string OnTransformCompleteString(string responseText) { if (TransformString != null) TransformString(responseText); return responseText; } /// <summary> /// Wrapper method form OnTransformString that handles /// stream to string and vice versa conversions /// </summary> /// <param name="ms"></param> /// <returns></returns> internal MemoryStream OnTransformCompleteStringInternal(MemoryStream ms) { if (TransformString == null) return ms; //string content = ms.GetAsString(); string content = HttpContext.Current.Response.ContentEncoding.GetString(ms.ToArray()); content = TransformString(content); byte[] buffer = HttpContext.Current.Response.ContentEncoding.GetBytes(content); ms = new MemoryStream(); ms.Write(buffer, 0, buffer.Length); //ms.WriteString(content); return ms; } /// <summary> /// /// </summary> public override bool CanRead { get { return true; } } public override bool CanSeek { get { return true; } } /// <summary> /// /// </summary> public override bool CanWrite { get { return true; } } /// <summary> /// /// </summary> public override long Length { get { return 0; } } /// <summary> /// /// </summary> public override long Position { get { return _position; } set { _position = value; } } /// <summary> /// /// </summary> /// <param name="offset"></param> /// <param name="direction"></param> /// <returns></returns> public override long Seek(long offset, System.IO.SeekOrigin direction) { return _stream.Seek(offset, direction); } /// <summary> /// /// </summary> /// <param name="length"></param> public override void SetLength(long length) { _stream.SetLength(length); } /// <summary> /// /// </summary> public override void Close() { _stream.Close(); } /// <summary> /// Override flush by writing out the cached stream data /// </summary> public override void Flush() { if (IsCaptured && _cacheStream.Length > 0) { // Check for transform implementations _cacheStream = OnTransformCompleteStream(_cacheStream); _cacheStream = OnTransformCompleteStringInternal(_cacheStream); OnCaptureStream(_cacheStream); OnCaptureStringInternal(_cacheStream); // write the stream back out if output was delayed if (IsOutputDelayed) _stream.Write(_cacheStream.ToArray(), 0, (int)_cacheStream.Length); // Clear the cache once we've written it out _cacheStream.SetLength(0); } // default flush behavior _stream.Flush(); } /// <summary> /// /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> /// <returns></returns> public override int Read(byte[] buffer, int offset, int count) { return _stream.Read(buffer, offset, count); } /// <summary> /// Overriden to capture output written by ASP.NET and captured /// into a cached stream that is written out later when Flush() /// is called. /// </summary> /// <param name="buffer"></param> /// <param name="offset"></param> /// <param name="count"></param> public override void Write(byte[] buffer, int offset, int count) { if ( IsCaptured ) { // copy to holding buffer only - we'll write out later _cacheStream.Write(buffer, 0, count); _cachePointer += count; } // just transform this buffer if (TransformWrite != null) buffer = OnTransformWrite(buffer); if (TransformWriteString != null) buffer = OnTransformWriteStringInternal(buffer); if (!IsOutputDelayed) _stream.Write(buffer, offset, buffer.Length); } } The key features are the events and corresponding OnXXX methods that handle the event hookups, and the Write() and Flush() methods of the stream implementation. All the rest of the members tend to be plain jane passthrough stream implementation code without much consequence. I do love the way Action<t> and Func<T> make it so easy to create the event signatures for the various events – sweet. A few Things to consider Performance Response.Filter is not great for performance in general as it adds another layer of indirection to the ASP.NET output pipeline, and this implementation in particular adds a memory hit as it basically duplicates the response output into the cached memory stream which is necessary since you may have to look at the entire response. If you have large pages in particular this can cause potentially serious memory pressure in your server application. So be careful of wholesale adoption of this (or other) Response.Filters. Make sure to do some performance testing to ensure it’s not killing your app’s performance. Response.Filter works everywhere A few questions came up in comments and discussion as to capturing ALL output hitting the site and – yes you can definitely do that by assigning a Response.Filter inside of a module. If you do this however you’ll want to be very careful and decide which content you actually want to capture especially in IIS 7 which passes ALL content – including static images/CSS etc. through the ASP.NET pipeline. So it is important to filter only on what you’re looking for – like the page extension or maybe more effectively the Response.ContentType. Response.Filter Chaining Originally I thought that filter chaining doesn’t work at all due to a bug in the stream implementation code. But it’s quite possible to assign multiple filters to the Response.Filter property. So the following actually works to both compress the output and apply the transformed content: WebUtils.GZipEncodePage(); ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; However the following does not work resulting in invalid content encoding errors: ResponseFilterStream filter = new ResponseFilterStream(Response.Filter); filter.TransformString += filter_TransformString; Response.Filter = filter; WebUtils.GZipEncodePage(); In other words multiple Response filters can work together but it depends entirely on the implementation whether they can be chained or in which order they can be chained. In this case running the GZip/Deflate stream filters apparently relies on the original content length of the output and chokes when the content is modified. But if attaching the compression first it works fine as unintuitive as that may seem. Resources Download example code Capture Output from ASP.NET Pages © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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• Dec 5th Links: ASP.NET, ASP.NET MVC, jQuery, Silverlight, Visual Studio

  - by ScottGu

  Here is the latest in my link-listing series.  Also check out my VS 2010 and .NET 4 series for another on-going blog series I’m working on. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] ASP.NET ASP.NET Code Samples Collection: J.D. Meier has a great post that provides a detailed round-up of ASP.NET code samples and tutorials from a wide variety of sources.  Lots of useful pointers. Slash your ASP.NET compile/load time without any hard work: Nice article that details a bunch of optimizations you can make to speed up ASP.NET project load and compile times. You might also want to read my previous blog post on this topic here. 10 Essential Tools for Building ASP.NET Websites: Great article by Stephen Walther on 10 great (and free) tools that enable you to more easily build great ASP.NET Websites.  Highly recommended reading. Optimize Images using the ASP.NET Sprite and Image Optimization Framework: A nice article by 4GuysFromRolla that discusses how to use the open-source ASP.NET Sprite and Image Optimization Framework (one of the tools recommended by Stephen in the previous article).  You can use this to significantly improve the load-time of your pages on the client. Formatting Dates, Times and Numbers in ASP.NET: Scott Mitchell has a great article that discusses formatting dates, times and numbers in ASP.NET.  A very useful link to bookmark.  Also check out James Michael’s DateTime is Packed with Goodies blog post for other DateTime tips. Examining ASP.NET’s Membership, Roles and Profile APIs (Part 18): Everything you could possibly want to known about ASP.NET’s built-in Membership, Roles and Profile APIs must surely be in this tutorial series. Part 18 covers how to store additional user info with Membership. ASP.NET with jQuery An Introduction to jQuery Templates: Stephen Walther has written an outstanding introduction and tutorial on the new jQuery Template plugin that the ASP.NET team has contributed to the jQuery project. Composition with jQuery Templates and jQuery Templates, Composite Rendering, and Remote Loading: Dave Ward has written two nice posts that talk about composition scenarios with jQuery Templates and some cool scenarios you can enable with them. Using jQuery and ASP.NET to Build a News Ticker: Scott Mitchell has a nice tutorial that demonstrates how to build a dynamically updated “news ticker” style UI with ASP.NET and jQuery. Checking All Checkboxes in a GridView using jQuery: Scott Mitchell has a nice post that covers how to use jQuery to enable a checkbox within a GridView’s header to automatically check/uncheck all checkboxes contained within rows of it. Using jQuery to POST Form Data to an ASP.NET AJAX Web Service: Rick Strahl has a nice post that discusses how to capture form variables and post them to an ASP.NET AJAX Web Service (.asmx). ASP.NET MVC ASP.NET MVC Diagnostics Using NuGet: Phil Haack has a nice post that demonstrates how to easily install a diagnostics page (using NuGet) that can help identify and diagnose common configuration issues within your apps. ASP.NET MVC 3 JsonValueProviderFactory: James Hughes has a nice post that discusses how to take advantage of the new JsonValueProviderFactory support built into ASP.NET MVC 3.  This makes it easy to post JSON payloads to MVC action methods. Practical jQuery Mobile with ASP.NET MVC: James Hughes has another nice post that discusses how to use the new jQuery Mobile library with ASP.NET MVC to build great mobile web applications. Credit Card Validator for ASP.NET MVC 3: Benjii Me has a nice post that demonstrates how to build a [CreditCard] validator attribute that can be used to easily validate credit card numbers are in the correct format with ASP.NET MVC. Silverlight Silverlight FireStarter Keynote and Sessions: A great blog post from John Papa that contains pointers and descriptions of all the great Silverlight content we published last week at the Silverlight FireStarter.  You can watch all of the talks online.  More details on my keynote and Silverlight 5 announcements can be found here. 31 Days of Windows Phone 7: 31 great tutorials on how to build Windows Phone 7 applications (using Silverlight).  Silverlight for Windows Phone Toolkit Update: David Anson has a nice post that discusses some of the additional controls provided with the Silverlight for Windows Phone Toolkit. Visual Studio JavaScript Editor Extensions: A nice (and free) Visual Studio plugin built by the web tools team that significantly improves the JavaScript intellisense support within Visual Studio. HTML5 Intellisense for Visual Studio: Gil has a blog post that discusses a new extension my team has posted to the Visual Studio Extension Gallery that adds HTML5 schema support to Visual Studio 2008 and 2010. Team Build + Web Deployment + Web Deploy + VS 2010 = Goodness: Visual blogs about how to enable a continuous deployment system with VS 2010, TFS 2010 and the Microsoft Web Deploy framework.  Visual Studio 2010 Emacs Emulation Extension and VIM Emulation Extension: Check out these two extensions if you are fond of Emacs and VIM key bindings and want to enable them within Visual Studio 2010. Hope this helps, Scott

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• C#: System.Lazy&lt;T&gt; and the Singleton Design Pattern

  - by James Michael Hare

  So we've all coded a Singleton at one time or another.  It's a really simple pattern and can be a slightly more elegant alternative to global variables.  Make no mistake, Singletons can be abused and are often over-used -- but occasionally you find a Singleton is the most elegant solution. For those of you not familiar with a Singleton, the basic Design Pattern is that a Singleton class is one where there is only ever one instance of the class created.  This means that constructors must be private to avoid users creating their own instances, and a static property (or method in languages without properties) is defined that returns a single static instance. 1: public class Singleton 2: { 3: // the single instance is defined in a static field 4: private static readonly Singleton _instance = new Singleton(); 5:  6: // constructor private so users can't instantiate on their own 7: private Singleton() 8: { 9: } 10:  11: // read-only property that returns the static field 12: public static Singleton Instance 13: { 14: get 15: { 16: return _instance; 17: } 18: } 19: } This is the most basic singleton, notice the key features: Static readonly field that contains the one and only instance. Constructor is private so it can only be called by the class itself. Static property that returns the single instance. Looks like it satisfies, right?  There's just one (potential) problem.  C# gives you no guarantee of when the static field _instance will be created.  This is because the C# standard simply states that classes (which are marked in the IL as BeforeFieldInit) can have their static fields initialized any time before the field is accessed.  This means that they may be initialized on first use, they may be initialized at some other time before, you can't be sure when. So what if you want to guarantee your instance is truly lazy.  That is, that it is only created on first call to Instance?  Well, there's a few ways to do this.  First we'll show the old ways, and then talk about how .Net 4.0's new System.Lazy<T> type can help make the lazy-Singleton cleaner. Obviously, we could take on the lazy construction ourselves, but being that our Singleton may be accessed by many different threads, we'd need to lock it down. 1: public class LazySingleton1 2: { 3: // lock for thread-safety laziness 4: private static readonly object _mutex = new object(); 5:  6: // static field to hold single instance 7: private static LazySingleton1 _instance = null; 8:  9: // property that does some locking and then creates on first call 10: public static LazySingleton1 Instance 11: { 12: get 13: { 14: if (_instance == null) 15: { 16: lock (_mutex) 17: { 18: if (_instance == null) 19: { 20: _instance = new LazySingleton1(); 21: } 22: } 23: } 24:  25: return _instance; 26: } 27: } 28:  29: private LazySingleton1() 30: { 31: } 32: } This is a standard double-check algorithm so that you don't lock if the instance has already been created.  However, because it's possible two threads can go through the first if at the same time the first time back in, you need to check again after the lock is acquired to avoid creating two instances. Pretty straightforward, but ugly as all heck.  Well, you could also take advantage of the C# standard's BeforeFieldInit and define your class with a static constructor.  It need not have a body, just the presence of the static constructor will remove the BeforeFieldInit attribute on the class and guarantee that no fields are initialized until the first static field, property, or method is called.   1: public class LazySingleton2 2: { 3: // because of the static constructor, this won't get created until first use 4: private static readonly LazySingleton2 _instance = new LazySingleton2(); 5:  6: // Returns the singleton instance using lazy-instantiation 7: public static LazySingleton2 Instance 8: { 9: get { return _instance; } 10: } 11:  12: // private to prevent direct instantiation 13: private LazySingleton2() 14: { 15: } 16:  17: // removes BeforeFieldInit on class so static fields not 18: // initialized before they are used 19: static LazySingleton2() 20: { 21: } 22: } Now, while this works perfectly, I hate it.  Why?  Because it's relying on a non-obvious trick of the IL to guarantee laziness.  Just looking at this code, you'd have no idea that it's doing what it's doing.  Worse yet, you may decide that the empty static constructor serves no purpose and delete it (which removes your lazy guarantee).  Worse-worse yet, they may alter the rules around BeforeFieldInit in the future which could change this. So, what do I propose instead?  .Net 4.0 adds the System.Lazy type which guarantees thread-safe lazy-construction.  Using System.Lazy<T>, we get: 1: public class LazySingleton3 2: { 3: // static holder for instance, need to use lambda to construct since constructor private 4: private static readonly Lazy<LazySingleton3> _instance 5: = new Lazy<LazySingleton3>(() => new LazySingleton3()); 6:  7: // private to prevent direct instantiation. 8: private LazySingleton3() 9: { 10: } 11:  12: // accessor for instance 13: public static LazySingleton3 Instance 14: { 15: get 16: { 17: return _instance.Value; 18: } 19: } 20: } Note, you need your lambda to call the private constructor as Lazy's default constructor can only call public constructors of the type passed in (which we can't have by definition of a Singleton).  But, because the lambda is defined inside our type, it has access to the private members so it's perfect. Note how the Lazy<T> makes it obvious what you're doing (lazy construction), instead of relying on an IL generation side-effect.  This way, it's more maintainable.  Lazy<T> has many other uses as well, obviously, but I really love how elegant and readable it makes the lazy Singleton.

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• C# 4.0: Dynamic Programming

  - by Paulo Morgado

  The major feature of C# 4.0 is dynamic programming. Not just dynamic typing, but dynamic in broader sense, which means talking to anything that is not statically typed to be a .NET object. Dynamic Language Runtime The Dynamic Language Runtime (DLR) is piece of technology that unifies dynamic programming on the .NET platform, the same way the Common Language Runtime (CLR) has been a common platform for statically typed languages. The CLR always had dynamic capabilities. You could always use reflection, but its main goal was never to be a dynamic programming environment and there were some features missing. The DLR is built on top of the CLR and adds those missing features to the .NET platform. The Dynamic Language Runtime is the core infrastructure that consists of: Expression Trees The same expression trees used in LINQ, now improved to support statements. Dynamic Dispatch Dispatches invocations to the appropriate binder. Call Site Caching For improved efficiency. Dynamic languages and languages with dynamic capabilities are built on top of the DLR. IronPython and IronRuby were already built on top of the DLR, and now, the support for using the DLR is being added to C# and Visual Basic. Other languages built on top of the CLR are expected to also use the DLR in the future. Underneath the DLR there are binders that talk to a variety of different technologies: .NET Binder Allows to talk to .NET objects. JavaScript Binder Allows to talk to JavaScript in SilverLight. IronPython Binder Allows to talk to IronPython. IronRuby Binder Allows to talk to IronRuby. COM Binder Allows to talk to COM. Whit all these binders it is possible to have a single programming experience to talk to all these environments that are not statically typed .NET objects. The dynamic Static Type Let’s take this traditional statically typed code: Calculator calculator = GetCalculator(); int sum = calculator.Sum(10, 20); Because the variable that receives the return value of the GetCalulator method is statically typed to be of type Calculator and, because the Calculator type has an Add method that receives two integers and returns an integer, it is possible to call that Sum method and assign its return value to a variable statically typed as integer. Now lets suppose the calculator was not a statically typed .NET class, but, instead, a COM object or some .NET code we don’t know he type of. All of the sudden it gets very painful to call the Add method: object calculator = GetCalculator(); Type calculatorType = calculator.GetType(); object res = calculatorType.InvokeMember("Add", BindingFlags.InvokeMethod, null, calculator, new object[] { 10, 20 }); int sum = Convert.ToInt32(res); And what if the calculator was a JavaScript object? ScriptObject calculator = GetCalculator(); object res = calculator.Invoke("Add", 10, 20); int sum = Convert.ToInt32(res); For each dynamic domain we have a different programming experience and that makes it very hard to unify the code. With C# 4.0 it becomes possible to write code this way: dynamic calculator = GetCalculator(); int sum = calculator.Add(10, 20); You simply declare a variable who’s static type is dynamic. dynamic is a pseudo-keyword (like var) that indicates to the compiler that operations on the calculator object will be done dynamically. The way you should look at dynamic is that it’s just like object (System.Object) with dynamic semantics associated. Anything can be assigned to a dynamic. dynamic x = 1; dynamic y = "Hello"; dynamic z = new List<int> { 1, 2, 3 }; At run-time, all object will have a type. In the above example x is of type System.Int32. When one or more operands in an operation are typed dynamic, member selection is deferred to run-time instead of compile-time. Then the run-time type is substituted in all variables and normal overload resolution is done, just like it would happen at compile-time. The result of any dynamic operation is always dynamic and, when a dynamic object is assigned to something else, a dynamic conversion will occur. Code Resolution Method double x = 1.75; double y = Math.Abs(x); compile-time double Abs(double x) dynamic x = 1.75; dynamic y = Math.Abs(x); run-time double Abs(double x) dynamic x = 2; dynamic y = Math.Abs(x); run-time int Abs(int x) The above code will always be strongly typed. The difference is that, in the first case the method resolution is done at compile-time, and the others it’s done ate run-time. IDynamicMetaObjectObject The DLR is pre-wired to know .NET objects, COM objects and so forth but any dynamic language can implement their own objects or you can implement your own objects in C# through the implementation of the IDynamicMetaObjectProvider interface. When an object implements IDynamicMetaObjectProvider, it can participate in the resolution of how method calls and property access is done. The .NET Framework already provides two implementations of IDynamicMetaObjectProvider: DynamicObject : IDynamicMetaObjectProvider The DynamicObject class enables you to define which operations can be performed on dynamic objects and how to perform those operations. For example, you can define what happens when you try to get or set an object property, call a method, or perform standard mathematical operations such as addition and multiplication. ExpandoObject : IDynamicMetaObjectProvider The ExpandoObject class enables you to add and delete members of its instances at run time and also to set and get values of these members. This class supports dynamic binding, which enables you to use standard syntax like sampleObject.sampleMember, instead of more complex syntax like sampleObject.GetAttribute("sampleMember").

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• MySQL 5.5 brings in new ways to authenticate users

  - by Georgi Kodinov

  Ever wanted to use your server's OS for authenticating MySQL users ? Or the corporate LDAP repository ? Unfortunately options like the above are plentiful nowadays. And providing hard-coded support for protocol X or service Y is not the best possible idea. MySQL 5.5 has taken the step into the right direction by providing an infrastructure allowing one to make the server understand different authentication protocols by creating a set of simple plugins (one for the client and one for the server). So now you can easily extend MySQL to search for and authenticate users in your favorite user directory. In fact the API supplied is so versatile that we took the possibility to re-design the current "native" authentication mechanism into a built-in always-on plugin ! OK, let me give you an example: Imagine we have a bunch of users defined in your OS, e.g. we have a user joro with his respective password. And we have a MySQL instance running on the same computer. It would not be unexpected to need to let joro access and/or modify MySQL data. The first step is to define him as a MySQL user. And there's a problem right there : MySQL's CREATE USER joro@localhost IDENTIFIED BY 'joros_password' statement needs a password. And this is a password in no way related to the password that joro have set up in the OS. What's worse : if joro changes his OS password this will in no way be reflected in MySQL. So he'll need to change his MySQL password in a separate step. Not very convenient, specially when you have a lot of users. This is a laborious setup for joro's DBA as well : he'll have to disable his access in both MySQL and the OS should he decides that joro's out of the "nice" list. Now mysql 5.5 to the rescue: Imagine that the smart DBA has created a MySQL server plugin that will check if the name of the user logging in is a valid and enabled OS name and if the password supplied to the mysql client matches the OS and has called this plugin 'auth_os'. Now all that's left to do is to define joro as a MySQL user that will be authenticated externally. This is done by the following command : CREATE USER 'joro'@'localhost' IDENTIFIED WITH 'auth_os'; Now joro can login to MySQL using his current OS password. Note : joro is still a valid MySQL user, so you can grant privileges to him just like you would for all other users. What's better: you can have users that authenticate using different mechanisms in the same server. So you can e.g. safely experiment with external authentication for selected users while keeping your current user base operational. What happens under the hood when joro logs in ? The server will find out by the user definition that it needs to use a non-default authentication and will ask the client to "switch" to using the appropriate client-side plugin (if of course the client is not already using it). If the client can't do this (e.g. because it's an old client or doesn't have the necessary plugin available) the server will reject the login. Otherwise the server will let the server-side plugin decide (while possibly talking to the client side plugin and the OS user directory) if this is a valid login or not. If it is the login process will continue as usual, while if it's not the login will get rejected. There's a lot more that MySQL 5.5 can do for you than just the simple case above. Stay tuned for more advanced use cases like mapping groups of external users to a single MySQL user (so you won't have to have 1-to-1 mapping between your external user directory and your mysql user repository) or ways to control the process as a DBA. Or you can simply skip ahead and read the relevant topics from MySQL's excellent online documentation. Or take a look at the example plugins in plugin/auth. Or take a look at the test suite in mysql-test/t/plugin_auth.test. Changelog entry: http://dev.mysql.com/doc/refman/5.5/en/news-5-5-7.html Primary new sections: Pluggable authentication Proxy users Client plugin C API functions Revised sections: New PROXY privilege New proxies_priv grant table Passwords might be external New external_user and proxy_user system variables New --default-auth and --plugin-dir mysql options New MYSQL_DEFAULT_AUTH and MYSQL_PLUGIN_DIR options for mysql_options() CREATE USER has IDENTIFIED WITH clause to specify auth plugin GRANT has PROXY privilege, IDENTIFIED WITH clause to specify auth plugin The data structure for writing client plugins

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• mysql not starting

  - by Eiriks

  I have a server running on rackspace.com, it been running for about a year (collecting data for a project) and no problems. Now it seems mysql froze (could not connect either through ssh command line, remote app (sequel pro) or web (pages using the db just froze). I got a bit eager to fix this quick and rebooted the virtual server, running ubuntu 10.10. It is a small virtual LAMP server (10gig storage - I'm only using 1, 256mb ram -has not been a problem). Now after the reboot, I cannot get mysql to start again. service mysql status mysql stop/waiting I believe this just means mysql is not running. How do I get this running again? service mysql start start: Job failed to start No. Just typing 'mysql' gives: mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (111) There is a .sock file in this folder, 'ls -l' gives: srwxrwxrwx 1 mysql mysql 0 2012-12-01 17:20 mysqld.sock From googleing this for a while now, I see that many talk about the logfile and my.cnf. Logs Not sure witch ones I should look at. This log-file is empty: 'var/log/mysql/error.log', so is the 'var/log/mysql.err' and 'var/log/mysql.log'. my.cnf is located in '/etc/mysql' and looks like this. Can't see anything clearly wrong with it either. # # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/run/mysqld/mysqld.sock # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] # # * Basic Settings # # # * IMPORTANT # If you make changes to these settings and your system uses apparmor, you may # also need to also adjust /etc/apparmor.d/usr.sbin.mysqld. # user = mysql socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp skip-external-locking # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. bind-address = 127.0.0.1 # # * Fine Tuning # key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 8 # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #max_connections = 100 #table_cache = 64 #thread_concurrency = 10 # # * Query Cache Configuration # query_cache_limit = 1M query_cache_size = 16M # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. # As of 5.1 you can enable the log at runtime! #general_log_file = /var/log/mysql/mysql.log #general_log = 1 log_error = /var/log/mysql/error.log # Here you can see queries with especially long duration #log_slow_queries = /var/log/mysql/mysql-slow.log #long_query_time = 2 #log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. #server-id = 1 #log_bin = /var/log/mysql/mysql-bin.log expire_logs_days = 10 max_binlog_size = 100M #binlog_do_db = include_database_name #binlog_ignore_db = include_database_name # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/ I need the data in the database (so i'd like to avoid reinstalling), and I need it back up running again. All hint, tips and solutions are welcomed and appreciated.

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• Updating the managed debugging API for .NET v4

  - by Brian Donahue

  In any successful investigation, the right tools play a big part in collecting evidence about the state of the "crime scene" as it was before the detectives arrived. Unfortunately for the Crash Scene Investigator, we don't have the budget to fly out to the customer's site, chalk the outline, and eat their doughnuts. We have to rely on the end-user to collect the evidence for us, which means giving them the fingerprint dust and the evidence baggies and leaving them to it. With that in mind, the Red Gate support team have been writing tools that can collect vital clues with a minimum of fuss. Years ago we would have asked for a memory dump, where we used to get the customer to run CDB.exe and produce dumps that we could analyze in-house, but those dumps were pretty unwieldy (500MB files) and the debugger often didn't dump exactly where we wanted, or made five or more dumps. What we wanted was just the minimum state information from the program at the time of failure, so we produced a managed debugger that captured every first and second-chance exception and logged the stack and a minimal amount of variables from the memory of the application, which could all be exported as XML. This caused less inconvenience to the end-user because it is much easier to send a 65KB XML file in an email than a 500MB file containing all of the application's memory. We don't need to have the entire victim shipped out to us when we just want to know what was under the fingernails. The thing that made creating a managed debugging tool possible was the MDbg Engine example written by Microsoft as part of the Debugging Tools for Windows distribution. Since the ICorDebug interface is a bit difficult to understand, they had kindly created some wrappers that provided an event-driven debugging model that was perfect for our needs, but .NET 4 applications under debugging started complaining that "The debugger's protocol is incompatible with the debuggee". The introduction of .NET Framework v4 had changed the managed debugging API significantly, however, without an update for the MDbg Engine code! After a few hours of research, I had finally worked out that most of the version 4 ICorDebug interface still works much the same way in "legacy" v2 mode and there was a relatively easy fix for the problem in that you can still get a reference to legacy ICorDebug by changing the way the interface is created. In .NET v2, the interface was acquired using the CreateDebuggingInterfaceFromVersion method in mscoree.dll. In v4, you must first create IClrMetaHost, enumerate the runtimes, get an ICLRRuntimeInfo interface to the .NET 4 runtime from that, and use the GetInterface method in mscoree.dll to return a "legacy" ICorDebug interface. The rest of the MDbg Engine will continue working the old way. Here is how I had changed the MDbg Engine code to support .NET v4: private void InitFromVersion(string debuggerVersion){if( debuggerVersion.StartsWith("v1") ){throw new ArgumentException( "Can't debug a version 1 CLR process (\"" + debuggerVersion + "\"). Run application in a version 2 CLR, or use a version 1 debugger instead." );} ICorDebug rawDebuggingAPI=null;if (debuggerVersion.StartsWith("v4")){Guid CLSID_MetaHost = new Guid("9280188D-0E8E-4867-B30C-7FA83884E8DE"); Guid IID_MetaHost = new Guid("D332DB9E-B9B3-4125-8207-A14884F53216"); ICLRMetaHost metahost = (ICLRMetaHost)NativeMethods.ClrCreateInterface(CLSID_MetaHost, IID_MetaHost); IEnumUnknown runtimes = metahost.EnumerateInstalledRuntimes(); ICLRRuntimeInfo runtime = GetRuntime(runtimes, debuggerVersion); //Defined in metahost.hGuid CLSID_CLRDebuggingLegacy = new Guid(0xDF8395B5, 0xA4BA, 0x450b, 0xA7, 0x7C, 0xA9, 0xA4, 0x77, 0x62, 0xC5, 0x20);Guid IID_ICorDebug = new Guid("3D6F5F61-7538-11D3-8D5B-00104B35E7EF"); Object res;runtime.GetInterface(ref CLSID_CLRDebuggingLegacy, ref IID_ICorDebug, out res); rawDebuggingAPI = (ICorDebug)res; }elserawDebuggingAPI = NativeMethods.CreateDebuggingInterfaceFromVersion((int)CorDebuggerVersion.Whidbey,debuggerVersion);if (rawDebuggingAPI != null)InitFromICorDebug(rawDebuggingAPI);elsethrow new ArgumentException("Support for debugging version " + debuggerVersion + " is not yet implemented");} The changes above will ensure that the debugger can support .NET Framework v2 and v4 applications with the same codebase, but we do compile two different applications: one targeting v2 and the other v4. As a footnote I need to add that some missing native methods and wrappers, along with the EnumerateRuntimes method code, came from the Mindbg project on Codeplex. Another change is that when using the MDbgEngine.CreateProcess to launch a process in the debugger, do not supply a null as the final argument. This does not work any more because GetCORVersion always returns "v2.0.50727" as the function has been deprecated in .NET v4. What's worse is that on a system with only .NET 4, the user will be prompted to download and install .NET v2! Not nice! This works much better: proc = m_Debugger.CreateProcess(ProcessName, ProcessArgs, DebugModeFlag.Default,String.Format("v{0}.{1}.{2}",System.Environment.Version.Major,System.Environment.Version.Minor,System.Environment.Version.Build)); Microsoft "unofficially" plan on updating the MDbg samples soon, but if you have an MDbg-based application, you can get it working right now by changing one method a bit and adding a few new interfaces (ICLRMetaHost, IEnumUnknown, and ICLRRuntimeInfo). The new, non-legacy implementation of MDbg Engine will add new, interesting features like dump-file support and by association I assume garbage-collection/managed object stats, so it will be well worth looking into if you want to extend the functionality of a managed debugger going forward.

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• C# 4.0: Named And Optional Arguments

  - by Paulo Morgado

  As part of the co-evolution effort of C# and Visual Basic, C# 4.0 introduces Named and Optional Arguments. First of all, let’s clarify what are arguments and parameters: Method definition parameters are the input variables of the method. Method call arguments are the values provided to the method parameters. In fact, the C# Language Specification states the following on §7.5: The argument list (§7.5.1) of a function member invocation provides actual values or variable references for the parameters of the function member. Given the above definitions, we can state that: Parameters have always been named and still are. Parameters have never been optional and still aren’t. Named Arguments Until now, the way the C# compiler matched method call definition arguments with method parameters was by position. The first argument provides the value for the first parameter, the second argument provides the value for the second parameter, and so on and so on, regardless of the name of the parameters. If a parameter was missing a corresponding argument to provide its value, the compiler would emit a compilation error. For this call: Greeting("Mr.", "Morgado", 42); this method: public void Greeting(string title, string name, int age) will receive as parameters: title: “Mr.” name: “Morgado” age: 42 What this new feature allows is to use the names of the parameters to identify the corresponding arguments in the form: name:value Not all arguments in the argument list must be named. However, all named arguments must be at the end of the argument list. The matching between arguments (and the evaluation of its value) and parameters will be done first by name for the named arguments and than by position for the unnamed arguments. This means that, for this method definition: public static void Method(int first, int second, int third) this call declaration: int i = 0; Method(i, third: i++, second: ++i); will have this code generated by the compiler: int i = 0; int CS$0$0000 = i++; int CS$0$0001 = ++i; Method(i, CS$0$0001, CS$0$0000); which will give the method the following parameter values: first: 2 second: 2 third: 0 Notice the variable names. Although invalid being invalid C# identifiers, they are valid .NET identifiers and thus avoiding collision between user written and compiler generated code. Besides allowing to re-order of the argument list, this feature is very useful for auto-documenting the code, for example, when the argument list is very long or not clear, from the call site, what the arguments are. Optional Arguments Parameters can now have default values: public static void Method(int first, int second = 2, int third = 3) Parameters with default values must be the last in the parameter list and its value is used as the value of the parameter if the corresponding argument is missing from the method call declaration. For this call declaration: int i = 0; Method(i, third: ++i); will have this code generated by the compiler: int i = 0; int CS$0$0000 = ++i; Method(i, 2, CS$0$0000); which will give the method the following parameter values: first: 1 second: 2 third: 1 Because, when method parameters have default values, arguments can be omitted from the call declaration, this might seem like method overloading or a good replacement for it, but it isn’t. Although methods like this: public static StreamReader OpenTextFile( string path, Encoding encoding = null, bool detectEncoding = true, int bufferSize = 1024) allow to have its calls written like this: OpenTextFile("foo.txt", Encoding.UTF8); OpenTextFile("foo.txt", Encoding.UTF8, bufferSize: 4096); OpenTextFile( bufferSize: 4096, path: "foo.txt", detectEncoding: false); The complier handles default values like constant fields taking the value and useing it instead of a reference to the value. So, like with constant fields, methods with parameters with default values are exposed publicly (and remember that internal members might be publicly accessible – InternalsVisibleToAttribute). If such methods are publicly accessible and used by another assembly, those values will be hard coded in the calling code and, if the called assembly has its default values changed, they won’t be assumed by already compiled code. At the first glance, I though that using optional arguments for “bad” written code was great, but the ability to write code like that was just pure evil. But than I realized that, since I use private constant fields, it’s OK to use default parameter values on privately accessed methods.

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• Your thoughts on Best Practices for Scientific Computing?

  - by John Smith

  A recent paper by Wilson et al (2014) pointed out 24 Best Practices for scientific programming. It's worth to have a look. I would like to hear opinions about these points from experienced programmers in scientific data analysis. Do you think these advices are helpful and practical? Or are they good only in an ideal world? Wilson G, Aruliah DA, Brown CT, Chue Hong NP, Davis M, Guy RT, Haddock SHD, Huff KD, Mitchell IM, Plumbley MD, Waugh B, White EP, Wilson P (2014) Best Practices for Scientific Computing. PLoS Biol 12:e1001745. http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001745 Box 1. Summary of Best Practices Write programs for people, not computers. (a) A program should not require its readers to hold more than a handful of facts in memory at once. (b) Make names consistent, distinctive, and meaningful. (c) Make code style and formatting consistent. Let the computer do the work. (a) Make the computer repeat tasks. (b) Save recent commands in a file for re-use. (c) Use a build tool to automate workflows. Make incremental changes. (a) Work in small steps with frequent feedback and course correction. (b) Use a version control system. (c) Put everything that has been created manually in version control. Don’t repeat yourself (or others). (a) Every piece of data must have a single authoritative representation in the system. (b) Modularize code rather than copying and pasting. (c) Re-use code instead of rewriting it. Plan for mistakes. (a) Add assertions to programs to check their operation. (b) Use an off-the-shelf unit testing library. (c) Turn bugs into test cases. (d) Use a symbolic debugger. Optimize software only after it works correctly. (a) Use a profiler to identify bottlenecks. (b) Write code in the highest-level language possible. Document design and purpose, not mechanics. (a) Document interfaces and reasons, not implementations. (b) Refactor code in preference to explaining how it works. (c) Embed the documentation for a piece of software in that software. Collaborate. (a) Use pre-merge code reviews. (b) Use pair programming when bringing someone new up to speed and when tackling particularly tricky problems. (c) Use an issue tracking tool. I'm relatively new to serious programming for scientific data analysis. When I tried to write code for pilot analyses of some of my data last year, I encountered tremendous amount of bugs both in my code and data. Bugs and errors had been around me all the time, but this time it was somewhat overwhelming. I managed to crunch the numbers at last, but I thought I couldn't put up with this mess any longer. Some actions must be taken. Without a sophisticated guide like the article above, I started to adopt "defensive style" of programming since then. A book titled "The Art of Readable Code" helped me a lot. I deployed meticulous input validations or assertions for every function, renamed a lot of variables and functions for better readability, and extracted many subroutines as reusable functions. Recently, I introduced Git and SourceTree for version control. At the moment, because my co-workers are much more reluctant about these issues, the collaboration practices (8a,b,c) have not been introduced. Actually, as the authors admitted, because all of these practices take some amount of time and effort to introduce, it may be generally hard to persuade your reluctant collaborators to comply them. I think I'm asking your opinions because I still suffer from many bugs despite all my effort on many of these practices. Bug fix may be, or should be, faster than before, but I couldn't really measure the improvement. Moreover, much of my time has been invested on defence, meaning that I haven't actually done much data analysis (offence) these days. Where is the point I should stop at in terms of productivity? I've already deployed: 1a,b,c, 2a, 3a,b,c, 4b,c, 5a,d, 6a,b, 7a,7b I'm about to have a go at: 5b,c Not yet: 2b,c, 4a, 7c, 8a,b,c (I could not really see the advantage of using GNU make (2c) for my purpose. Could anyone tell me how it helps my work with MATLAB?)

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• Workaround for datadude deployment bug - NullReferenceException

  - by jamiet

  I have come across a bug in Visual Studio 2010 Database Projects (aka datadude aka DPro aka Visual Studio Database Development Tools aka Visual Studio Team Edition for Database Professionals aka Juneau aka SQL Server Data Tools) that other people may encounter so, for the purposes of googling, I'm writing this blog post about it. Through my own googling I discovered that a Connect bug had already been raised about it (VS2010 Database project deploy - “SqlDeployTask” task failed unexpectedly, NullReferenceException), and coincidentally enough it was raised by my former colleague Tom Hunter (whom I have mentioned here before as the superhuman Tom Hunter) although it has not (at this time) received a reply from Microsoft. Tom provided a repro, namely that this syntactically valid function definition: CREATE FUNCTION [dbo].[Function1]()RETURNS TABLEASRETURN (    WITH cte AS (    SELECT 1 AS [c1]    FROM [$(Database3)].[dbo].[Table1]   )   SELECT 1 AS [c1]   FROM cte) would produce this nasty unhelpful error upon deployment: C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v10.0\TeamData\Microsoft.Data.Schema.TSqlTasks.targets(120,5): Error MSB4018: The "SqlDeployTask" task failed unexpectedly.System.NullReferenceException: Object reference not set to an instance of an object.   at Microsoft.Data.Schema.Sql.SchemaModel.SqlModelComparerBase.VariableSubstitution(SqlScriptProperty propertyValue, IDictionary`2 variables, Boolean& isChanged)   at Microsoft.Data.Schema.Sql.SchemaModel.SqlModelComparerBase.ArePropertiesEqual(IModelElement source, IModelElement target, ModelPropertyClass propertyClass, ModelComparerConfiguration configuration)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareProperties(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithoutCompareName(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithSameType(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean ignoreComparingName, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, Boolean compareFromRootElement, ModelComparisonChangeDefinition& changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareChildren(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareParentElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes, Boolean isComposing)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithoutCompareName(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithSameType(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean ignoreComparingName, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, Boolean compareFromRootElement, ModelComparisonChangeDefinition& changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareChildren(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareParentElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes, Boolean isComposing)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithoutCompareName(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, ModelComparisonResult result, ModelComparisonChangeDefinition changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareElementsWithSameType(IModelElement sourceElement, IModelElement targetElement, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean ignoreComparingName, Boolean parentExplicitlyIncluded, Boolean compareElementOnly, Boolean compareFromRootElement, ModelComparisonChangeDefinition& changes)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareAllElementsForOneType(ModelElementClass type, ModelComparerConfiguration configuration, ModelComparisonResult result, Boolean compareOrphanedElements)   at Microsoft.Data.Schema.SchemaModel.ModelComparer.CompareStore(ModelStore source, ModelStore target, ModelComparerConfiguration configuration)   at Microsoft.Data.Schema.Build.SchemaDeployment.CompareModels()   at Microsoft.Data.Schema.Build.SchemaDeployment.PrepareBuildPlan()   at Microsoft.Data.Schema.Build.SchemaDeployment.Execute(Boolean executeDeployment)   at Microsoft.Data.Schema.Build.SchemaDeployment.Execute()   at Microsoft.Data.Schema.Tasks.DBDeployTask.Execute()   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()   at Microsoft.Build.BackEnd.TaskBuilder.ExecuteInstantiatedTask(ITaskExecutionHost taskExecutionHost, TaskLoggingContext taskLoggingContext, TaskHost taskHost, ItemBucket bucket, TaskExecutionMode howToExecuteTask, Boolean& taskResult)   Done executing task "SqlDeployTask" -- FAILED.  Done building target "DspDeploy" in project "Lloyds.UKTax.DB.UKtax.dbproj" -- FAILED. Done executing task "CallTarget" -- FAILED.Done building target "DBDeploy" in project It turns out there are a certain set of circumstances that need to be met for this error to occur: The object being deployed is an inline function  (may also exist for multistatement and scalar functions - I haven't tested that) That object includes SQLCMD variable references The object has already been deployed successfully Just to reiterate that last bullet point, the error does not occur when you deploy the function for the first time, only on the subsequent deployment.   Luckily I have a direct line into a guy on the development team so I fired off an email on Friday evening and today (Monday) I received a reply back telling me that there is a simple fix, one simply has to remove the parentheses that wrap the SQL statement. So, in the case of Tom's repro, the function definition simpy has to be changed to: CREATE FUNCTION [dbo].[Function1]()RETURNS TABLEASRETURN --(    WITH cte AS (    SELECT 1 AS [c1]    FROM [$(Database3)].[dbo].[Table1]   )   SELECT 1 AS [c1]   FROM cte--) I have commented out the offending parentheses rather than removing them just to emphasize the point. Thereafter the function will deploy fine. I tested this out on my own project this morning and can confirm that this fix does indeed work.   I have been told that the bug CAN be reproduced in the Release Candidate (RC) 0 build of SQL Server Data Tools in SQL Server 2010 so am hoping that a fix makes it in for the Release-To-Manufacturing (RTM) build. Hope this helps @jamiet

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