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  • mcrypt_encrypt fails to initialise

    - by mixkat
    I am trying to encrypt some data in PHP using the Rijndael cipher in CBC mode with a 256bit key but for some reason I get the following error message: mcrypt_encrypt() Module initialization failed My code: $hashKey = hash('sha256',$key); $iv = hash('sha256',$hashKey); // ------Cipher-------------key-------------Data-------------Mode---------IV-- $encryptedQuestion = base64_encode(mcrypt_encrypt('MCRYPT_RIJNDAEL_256', $hashKey , $_POST['question'], MCRYPT_MODE_CBC, $iv)); Can anyone see whats wrong with this?

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  • Are parametrized calls/sanitization/escaping characters necessary for hashed password fields in SQL queries?

    - by Computerish
    When writing a login system for a website, it is standard to use some combination of parameterized calls, sanitizing the user input, and/or escaping special characters to prevent SQL injection attacks. Any good login system, however, should also hash (and possibly salt) every password before it goes into an SQL query, so is it still necessary to worry about SQL injection attacks in passwords? Doesn't a hash completely eliminate any possibility of an SQL injection attack on its own?

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  • Check directory for files, retrieve first file

    - by Lowgain
    I'm writing a small ruby daemon that I am hoping will do the following: Check if a specific directory has files (in this case, .yml files) If so, take the first file (numerically sorted preferrably), and parse into a hash Do a 'yield', with this hash as the argument What I have right now is like: loop do get_next_in_queue { |s| THINGS } end def get_next_in_queue queue_dir = Dir[File.dirname(__FILE__)+'/../queue'] info = YAML::load_file(queue_dir[0]) #not sure if this works or not yield info end I'd like to make the yield conditional if possible, so it only happens if a file is actually found. Thanks!

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  • Open SSL without SHA1

    - by Hellnar
    Is there any way to use Open SSL without any SHA1 hash functions and using one of SHA2 functions instead of it? I think firstly, I should find all the functions that call SHA1 algorithm, and I should understand why SHA1 is still used. While changing the hash function, the bits are different in SHA1 and SHA2 so it may cause some problems. It confuses me...

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  • If I never ever use HashSet, should I still implement GetHashCode?

    - by Dimitri C.
    I never need to store objects in a hash table. The reason is twofold: coming up with a good hash function is difficult and error prone. an AVL tree is almost always fast enough, and it merely requires a strict order predicate, which is much easier to implement. The Equals() operation on the other hand is a very frequently used function. Therefore I wonder whether it is necessary to implement GetHashCode (which I never need) when implementing the Equals function (which I often need)?

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  • PHP user sessions

    - by Temek
    I'm bit confused. I've been building my sites with my own session system, but i'm not sure how secure the php's own session system is. My session system usually just has user id and quite harsh hash, which does not include user name or password for generation. I save the hash in the user database and as a cookie to confirm the user session on every page load. So my question is should i keep using my own systems or try out php sessions?

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  • c++ program debugged well with Cygwin4 (under Netbeans 7.2) but not with MinGW (under QT 4.8.1)

    - by GoldenAxe
    I have a c++ program which take a map text file and output it to a graph data structure I have made, I am using QT as I needed cross-platform program and GUI as well as visual representation of the map. I have several maps in different sizes (8x8 to 4096x4096). I am using unordered_map with a vector as key and vertex as value, I'm sending hash(1) and equal functions which I wrote to the unordered_map in creation. Under QT I am debugging my program with QT 4.8.1 for desktop MinGW (QT SDK), the program works and debug well until I try the largest map of 4096x4096, then the program stuck with the following error: "the inferior stopped because it received a signal from operating system", when debugging, the program halt at the hash function which used inside the unordered_map and not as part of the insertion state, but at a getter(2). Under Netbeans IDE 7.2 and Cygwin4 all works fine (debug and run). some code info: typedef std::vector<double> coordinate; typedef std::unordered_map<coordinate const*, Vertex<Element>*, container_hash, container_equal> vertexsContainer; vertexsContainer *m_vertexes (1) hash function: struct container_hash { size_t operator()(coordinate const *cord) const { size_t sum = 0; std::ostringstream ss; for ( auto it = cord->begin() ; it != cord->end() ; ++it ) { ss << *it; } sum = std::hash<std::string>()(ss.str()); return sum; } }; (2) the getter: template <class Element> Vertex<Element> *Graph<Element>::getVertex(const coordinate &cord) { try { Vertex<Element> *v = m_vertexes->at(&cord); return v; } catch (std::exception& e) { return NULL; } } I was thinking maybe it was some memory issue at the beginning, so before I was thinking of trying Netbeans I checked it with QT on my friend pc with a 16GB RAM and got the same error. Thanks.

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  • download multiples files in one request

    - by alexperto
    I don't know if it is posible, but I'd like to download a group of pdf's in only one request this is the way I download a particular invoice: def show @invoice = Invoice.find_by_invoice_hash params[:hash] respond_to do |format| format.html format.xml do send_data File.read( @invoice.xml_path ), type: 'text/xml', filename: "invoice_#{ @invoice.id }.xml", disposition: 'attachment' end format.pdf do render :pdf => @invoice.hash, layout: 'pdf', footer: { right: "printed at: #{Date.today}" } end end end What do you suggest me to do?

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  • Postfix certificate verification failed for smtp.gmail.com

    - by Andi Unpam
    I have problem, my email server using postfix with gmail smtp, i use account google apps, but always ask for SASL authentication failed, I sent an email using php script, after I see the error logs in the wrong password, after I open the URL from the browser and no verification postfixnya captcha and could return, but after 2-3 days later happen like that again. This my config postfix #myorigin = /etc/mailname smtpd_banner = Hostingbitnet Mail Server biff = no append_dot_mydomain = no readme_directory = no myhostname = webmaster.hostingbitnet.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = localhost, webmaster.hostingbitnet.com, localhost.localdomain, 103.9.126.163 relayhost = [smtp.googlemail.com]:587 relay_transport = relay relay_destination_concurrency_limit = 1 mynetworks = 127.0.0.0/8, 192.168.0.0/16, 172.16.0.0/16, 10.0.0.0/8, 103.9.126.0/24 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all default_transport = smtp relayhost = [smtp.gmail.com]:587 smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/google-apps smtp_sasl_security_options = noanonymous smtp_use_tls = yes smtp_sender_dependent_authentication = yes tls_random_source = dev:/dev/urandom default_destination_concurrency_limit = 1 smtp_tls_CAfile = /etc/postfix/tls/root.crt smtp_tls_cert_file = /etc/postfix/tls/cert.pem smtp_tls_key_file = /etc/postfix/tls/privatekey.pem smtp_tls_session_cache_database = btree:$data_directory/smtp_tls_session_cache smtp_tls_security_level = may smtp_tls_loglevel = 1 smtpd_tls_CAfile = /etc/postfix/tls/root.crt smtpd_tls_cert_file = /etc/postfix/tls/cert.pem smtpd_tls_key_file = /etc/postfix/tls/privatekey.pem smtpd_tls_session_cache_database = btree:$data_directory/smtpd_tls_session_cache smtpd_tls_security_level = may smtpd_tls_loglevel = 1 #secure smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,check_client_access hash:/var/lib/pop-before-smtp/hosts,reject_unauth_destination Log from mail.log Oct 30 14:51:13 webmaster postfix/smtp[9506]: Untrusted TLS connection established to smtp.gmail.com[74.125.25.109]:587: TLSv1 with cipher RC4-SHA (128/128 bits) Oct 30 14:51:15 webmaster postfix/smtp[9506]: 87E2739400B1: SASL authentication failed; server smtp.gmail.com[74.125.25.109] said: 535-5.7.1 Please log in with your web browser and then try again. Learn more at?535 5.7.1 https://support.google.com/mail/bin/answer.py?answer=78754 ix9sm156630pbc.7 Oct 30 14:51:15 webmaster postfix/smtp[9506]: setting up TLS connection to smtp.gmail.com[74.125.25.108]:587 Oct 30 14:51:15 webmaster postfix/smtp[9506]: certificate verification failed for smtp.gmail.com[74.125.25.108]:587: untrusted issuer /C=US/O=Equifax/OU=Equifax Secure Certificate Authority Oct 30 14:51:16 webmaster postfix/smtp[9506]: Untrusted TLS connection established to smtp.gmail.com[74.125.25.108]:587: TLSv1 with cipher RC4-SHA (128/128 bits) Oct 30 14:51:17 webmaster postfix/smtp[9506]: 87E2739400B1: to=<[email protected]>, relay=smtp.gmail.com[74.125.25.108]:587, delay=972, delays=967/0.03/5.5/0, dsn=4.7.1, status=deferred (SASL authentication failed; server smtp.gmail.com[74.125.25.108] said: 535-5.7.1 Please log in with your web browser and then try again. Learn more at?535 5.7.1 https://support.google.com/mail/bin/answer.py?answer=78754 s1sm3850paz.0) Oct 30 14:51:17 webmaster postfix/error[9508]: B3960394009D: to=<[email protected]>, orig_to=<root>, relay=none, delay=29992, delays=29986/5.6/0/0.07, dsn=4.7.1, status=deferred (delivery temporarily suspended: SASL authentication failed; server smtp.gmail.com[74.125.25.108] said: 535-5.7.1 Please log in with your web browser and then try again. Learn more at?535 5.7.1 https://support.google.com/mail/bin/answer.py?answer=78754 s1sm3850paz.0) BTW I made cert follow the link here http://koti.kapsi.fi/ptk/postfix/postfix-tls-cacert.shtml and it worked, but after 2/3 days my email back to problem invalid SASL, and then i'm required to log in use a browser and enter the captcha there but success log in after input captcha, and my email server can send emails from telnet or php script. but it will be back in trouble after 2/3days later. My question is how to make it permanent certificate? Thanks n greeting.

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  • Postfix sasl login failing no mechanism found

    - by Nat45928
    following the link here: http://flurdy.com/docs/postfix/ with posfix, courier, MySql, and sasl gave me a web server that has imap functionality working fine but when i go to log into the server to send a message using the same user id and password for connecting the the imap server it rejects my login to the smtp server. If i do not specify a login for the outgoing mail server then it will send the message just fine. the error in postfix's log is: Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: connect from unknown[10.0.0.50] Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: warning: SASL authentication failure: unable to canonify user and get auxprops Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: warning: unknown[10.0.0.50]: SASL DIGEST-MD5 authentication failed: no mechanism available Jul 6 17:26:10 Sj-Linux postfix/smtpd[19139]: warning: unknown[10.0.0.50]: SASL LOGIN authentication failed: no mechanism available Ive checked all usernames and passwords for mysql. what could be going wrong? edit: here is some other information: installed libraires for postfix, courier and sasl: aptitude install postfix postfix-mysql aptitude install libsasl2-modules libsasl2-modules-sql libgsasl7 libauthen-sasl-cyrus-perl sasl2-bin libpam-mysql aptitude install courier-base courier-authdaemon courier-authlib-mysql courier-imap courier-imap-ssl courier-ssl and here is my /etc/postfix/main.cf myorigin = domain.com smtpd_banner = $myhostname ESMTP $mail_name biff = no # appending .domain is the MUA's job. append_dot_mydomain = no # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h readme_directory = no # TLS parameters smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key smtpd_use_tls=yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for # information on enabling SSL in the smtp client. #myhostname = my hostname alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname local_recipient_maps = mydestination = relayhost = mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all mynetworks_style = host # how long if undelivered before sending warning update to sender delay_warning_time = 4h # will it be a permanent error or temporary unknown_local_recipient_reject_code = 450 # how long to keep message on queue before return as failed. # some have 3 days, I have 16 days as I am backup server for some people # whom go on holiday with their server switched off. maximal_queue_lifetime = 7d # max and min time in seconds between retries if connection failed minimal_backoff_time = 1000s maximal_backoff_time = 8000s # how long to wait when servers connect before receiving rest of data smtp_helo_timeout = 60s # how many address can be used in one message. # effective stopper to mass spammers, accidental copy in whole address list # but may restrict intentional mail shots. # but may restrict intentional mail shots. smtpd_recipient_limit = 16 # how many error before back off. smtpd_soft_error_limit = 3 # how many max errors before blocking it. smtpd_hard_error_limit = 12 # Requirements for the HELO statement smtpd_helo_restrictions = permit_mynetworks, permit # Requirements for the sender details smtpd_sender_restrictions = permit_sasl_authenticated, permit_mynetworks, warn_if_reject reject_non_fqdn_sender, reject_unknown_sender_domain, reject_unauth_pipelining, permit # Requirements for the connecting server smtpd_client_restrictions = reject_rbl_client sbl.spamhaus.org, reject_rbl_client blackholes.easynet.nl, reject_rbl_client dnsbl.njabl.org # Requirement for the recipient address smtpd_recipient_restrictions = reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_non_fqdn_recipient, reject_unknown_recipient_domain, reject_unauth_destination, permit smtpd_data_restrictions = reject_unauth_pipelining # require proper helo at connections smtpd_helo_required = yes # waste spammers time before rejecting them smtpd_delay_reject = yes disable_vrfy_command = yes # not sure of the difference of the next two # but they are needed for local aliasing alias_maps = hash:/etc/postfix/aliases alias_database = hash:/etc/postfix/aliases # this specifies where the virtual mailbox folders will be located virtual_mailbox_base = /var/spool/mail/virtual # this is for the mailbox location for each user virtual_mailbox_maps = mysql:/etc/postfix/mysql_mailbox.cf # and this is for aliases virtual_alias_maps = mysql:/etc/postfix/mysql_alias.cf # and this is for domain lookups virtual_mailbox_domains = mysql:/etc/postfix/mysql_domains.cf # this is how to connect to the domains (all virtual, but the option is there) # not used yet # transport_maps = mysql:/etc/postfix/mysql_transport.cf virtual_uid_maps = static:5000 virtual_gid_maps = static:5000 # SASL smtpd_sasl_auth_enable = yes # If your potential clients use Outlook Express or other older clients # this needs to be set to yes broken_sasl_auth_clients = yes smtpd_sasl_security_options = noanonymous smtpd_sasl_local_domain =

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  • postfix: Temporary lookup failure for FQDN

    - by Thufir
    I'm using the FQDN of dur.bounceme.net which I want to resolve(?) to localhost. That is, I want mail to [email protected] to get delivered to user@localhost. I've tried following the Ubuntu guide on this and seem to be going in circles a bit. root@dur:~# root@dur:~# postfix stop postfix/postfix-script: stopping the Postfix mail system root@dur:~# postfix start postfix/postfix-script: starting the Postfix mail system root@dur:~# telnet dur.bounceme.net 25 Trying 127.0.1.1... telnet: Unable to connect to remote host: Connection refused root@dur:~# root@dur:~# telnet localhost 25 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. 220 dur.bounceme.net ESMTP Postfix (Ubuntu) ehlo dur 250-dur.bounceme.net 250-PIPELINING 250-SIZE 10240000 250-VRFY 250-ETRN 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN mail from:[email protected] 250 2.1.0 Ok rcpt to:[email protected] 451 4.3.0 <[email protected]>: Temporary lookup failure rcpt to:thufir@localhost 451 4.3.0 <thufir@localhost>: Temporary lookup failure quit 221 2.0.0 Bye Connection closed by foreign host. root@dur:~# root@dur:~# grep telnet /var/log/mail.log Aug 28 00:24:45 dur postfix/smtpd[18256]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 451 4.3.0 <thufir@localhost>: Temporary lookup failure; from=<[email protected]> to=<thufir@localhost> proto=ESMTP helo=<dur> Aug 28 00:24:58 dur postfix/smtpd[18256]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 451 4.3.0 <[email protected]>: Temporary lookup failure; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<dur> Aug 28 00:54:55 dur postfix/smtpd[18825]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 451 4.3.0 <[email protected]>: Temporary lookup failure; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<dur> Aug 28 00:55:08 dur postfix/smtpd[18825]: NOQUEUE: reject: RCPT from localhost[127.0.0.1]: 451 4.3.0 <thufir@localhost>: Temporary lookup failure; from=<[email protected]> to=<thufir@localhost> proto=ESMTP helo=<dur> root@dur:~# root@dur:~# postconf -n alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases append_dot_mydomain = no biff = no broken_sasl_auth_clients = yes config_directory = /etc/postfix default_transport = smtp home_mailbox = Maildir/ inet_interfaces = loopback-only mailbox_command = /usr/lib/dovecot/deliver -c /etc/dovecot/conf.d/01-mail-stack-delivery.conf -m "${EXTENSION}" mailbox_size_limit = 0 mailman_destination_recipient_limit = 1 mydestination = dur, dur.bounceme.net, localhost.bounceme.net, localhost myhostname = dur.bounceme.net mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 readme_directory = no recipient_delimiter = + relay_domains = lists.dur.bounceme.net relay_transport = relay relayhost = smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtp_use_tls = yes smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) smtpd_recipient_restrictions = reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination smtpd_sasl_auth_enable = yes smtpd_sasl_authenticated_header = yes smtpd_sasl_local_domain = $myhostname smtpd_sasl_path = private/dovecot-auth smtpd_sasl_security_options = noanonymous smtpd_sasl_type = dovecot smtpd_tls_auth_only = yes smtpd_tls_cert_file = /etc/ssl/certs/ssl-mail.pem smtpd_tls_key_file = /etc/ssl/private/ssl-mail.key smtpd_tls_mandatory_ciphers = medium smtpd_tls_mandatory_protocols = SSLv3, TLSv1 smtpd_tls_received_header = yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtpd_use_tls = yes tls_random_source = dev:/dev/urandom transport_maps = hash:/etc/postfix/transport root@dur:~#

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  • Oracle Virtual Server OEL vm fails to start - kernel panic on cpu identify

    - by Towndrunk
    I am in the process of following a guide to setup various oracle vm templates, so far I have installed OVS 2. 2 and got the OVM Manager working, imported the template for OEL5U5 and created a vm from it.. the problem comes when starting that vm. The log in the OVMM console shows the following; Update VM Status - Running Configure CPU Cap Set CPU Cap: failed:<Exception: failed:<Exception: ['xm', 'sched-credit', '-d', '32_EM11g_OVM', '-c', '0'] => Error: Domain '32_EM11g_OVM' does not exist. StackTrace: File "/opt/ovs-agent-2.3/OVSXXenVMConfig.py", line 2531, in xen_set_cpu_cap run_cmd(args=['xm', File "/opt/ovs-agent-2.3/OVSCommons.py", line 92, in run_cmd raise Exception('%s => %s' % (args, err)) The xend.log shows; [2012-11-12 16:42:01 7581] DEBUG (DevController:139) Waiting for devices vtpm [2012-11-12 16:42:01 7581] INFO (XendDomain:1180) Domain 32_EM11g_OVM (3) unpaused. [2012-11-12 16:42:03 7581] WARNING (XendDomainInfo:1907) Domain has crashed: name=32_EM11g_OVM id=3. [2012-11-12 16:42:03 7581] ERROR (XendDomainInfo:2041) VM 32_EM11g_OVM restarting too fast (Elapsed time: 11.377262 seconds). Refusing to restart to avoid loops .> [2012-11-12 16:42:03 7581] DEBUG (XendDomainInfo:2757) XendDomainInfo.destroy: domid=3 [2012-11-12 16:42:12 7581] DEBUG (XendDomainInfo:2230) Destroying device model [2012-11-12 16:42:12 7581] INFO (image:553) 32_EM11g_OVM device model terminated I have set_on_crash="preserve" in the vm.cfg and have then run xm create -c to get the console screen while booting and this is the log of what happens.. Started domain 32_EM11g_OVM (id=4) Bootdata ok (command line is ro root=LABEL=/ ) Linux version 2.6.18-194.0.0.0.3.el5xen ([email protected]) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-48)) #1 SMP Mon Mar 29 18:27:00 EDT 2010 BIOS-provided physical RAM map: Xen: 0000000000000000 - 0000000180800000 (usable)> No mptable found. Built 1 zonelists. Total pages: 1574912 Kernel command line: ro root=LABEL=/ Initializing CPU#0 PID hash table entries: 4096 (order: 12, 32768 bytes) Xen reported: 1600.008 MHz processor. Console: colour dummy device 80x25 Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes) Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes) Software IO TLB disabled Memory: 6155256k/6299648k available (2514k kernel code, 135548k reserved, 1394k data, 184k init) Calibrating delay using timer specific routine.. 4006.42 BogoMIPS (lpj=8012858) Security Framework v1.0.0 initialized SELinux: Initializing. selinux_register_security: Registering secondary module capability Capability LSM initialized as secondary Mount-cache hash table entries: 256 CPU: L1 I Cache: 64K (64 bytes/line), D cache 16K (64 bytes/line) CPU: L2 Cache: 2048K (64 bytes/line) general protection fault: 0000 [1] SMP last sysfs file: CPU 0 Modules linked in: Pid: 0, comm: swapper Not tainted 2.6.18-194.0.0.0.3.el5xen #1 RIP: e030:[ffffffff80271280] [ffffffff80271280] identify_cpu+0x210/0x494 RSP: e02b:ffffffff80643f70 EFLAGS: 00010212 RAX: 0040401000810008 RBX: 0000000000000000 RCX: 00000000c001001f RDX: 0000000000404010 RSI: 0000000000000001 RDI: 0000000000000005 RBP: ffffffff8063e980 R08: 0000000000000025 R09: ffff8800019d1000 R10: 0000000000000026 R11: ffff88000102c400 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffffff805d2000(0000) knlGS:0000000000000000 CS: e033 DS: 0000 ES: 0000 Process swapper (pid: 0, threadinfo ffffffff80642000, task ffffffff804f4b80) Stack: 0000000000000000 ffffffff802d09bb ffffffff804f4b80 0000000000000000 0000000021100800 0000000000000000 0000000000000000 ffffffff8064cb00 0000000000000000 0000000000000000 Call Trace: [ffffffff802d09bb] kmem_cache_zalloc+0x62/0x80 [ffffffff8064cb00] start_kernel+0x210/0x224 [ffffffff8064c1e5] _sinittext+0x1e5/0x1eb Code: 0f 30 b8 73 00 00 00 f0 0f ab 45 08 e9 f0 00 00 00 48 89 ef RIP [ffffffff80271280] identify_cpu+0x210/0x494 RSP ffffffff80643f70 0 Kernel panic - not syncing: Fatal exception clear as mud to me. are there any other logs that will help me? I have now deployed another vm from the same template and used the default vm settings rather than adding more memory etc - I get exactly the same error.

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  • Openvpn issue with linux

    - by catsy
    So I've tried to setup openvpn, I followed some guide but it's stuck att "initialization sequence completed" with no connection and I can't find any working solution... here's the log: $Sun Sep 23 19:14:32 2012 OpenVPN 2.1.0 i486-pc-linux-gnu [SSL] [LZO2] [EPOLL] [PKCS11] [MH] [PF_INET6] [eurephia] built on Jul 20 2010 Enter Auth Username:pumpedup Enter Auth Password: Sun Sep 23 19:14:37 2012 WARNING: No server certificate verification method has been enabled. See http://openvpn.net/howto.html#mitm for more info. Sun Sep 23 19:14:37 2012 NOTE: OpenVPN 2.1 requires '--script-security 2' or higher to call user-defined scripts or executables Sun Sep 23 19:14:37 2012 LZO compression initialized Sun Sep 23 19:14:37 2012 Control Channel MTU parms [ L:1542 D:138 EF:38 EB:0 ET:0 EL:0 ] Sun Sep 23 19:14:38 2012 Data Channel MTU parms [ L:1542 D:1450 EF:42 EB:135 ET:0 EL:0 AF:3/1 ] Sun Sep 23 19:14:38 2012 Local Options hash (VER=V4): '41690919' Sun Sep 23 19:14:38 2012 Expected Remote Options hash (VER=V4): '530fdded' Sun Sep 23 19:14:38 2012 Socket Buffers: R=[163840-131072] S=[163840-131072] Sun Sep 23 19:14:38 2012 UDPv4 link local: [undef] Sun Sep 23 19:14:38 2012 UDPv4 link remote: [AF_INET]192.162.102.162:1194 Sun Sep 23 19:14:38 2012 TLS: Initial packet from [AF_INET]192.162.102.162:1194, sid=87a95723 a6d7b7f9 Sun Sep 23 19:14:38 2012 WARNING: this configuration may cache passwords in memory -- use the auth-nocache option to prevent this Sun Sep 23 19:14:38 2012 VERIFY OK: depth=1, /C=NV/ST=NV/L=nVPN/O=nVpn/CN=nVpn_CA/[email protected] Sun Sep 23 19:14:38 2012 VERIFY OK: depth=0, /C=NV/ST=NV/L=nVPN/O=nVpn/CN=server/[email protected] Sun Sep 23 19:14:39 2012 WARNING: 'link-mtu' is used inconsistently, local='link-mtu 1542', remote='link-mtu 6042' Sun Sep 23 19:14:39 2012 WARNING: 'tun-mtu' is used inconsistently, local='tun-mtu 1500', remote='tun-mtu 6000' Sun Sep 23 19:14:39 2012 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key Sun Sep 23 19:14:39 2012 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication Sun Sep 23 19:14:39 2012 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key Sun Sep 23 19:14:39 2012 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication Sun Sep 23 19:14:39 2012 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA Sun Sep 23 19:14:39 2012 [server] Peer Connection Initiated with [AF_INET]192.162.102.162:1194 Sun Sep 23 19:14:41 2012 SENT CONTROL [server]: 'PUSH_REQUEST' (status=1) Sun Sep 23 19:14:41 2012 PUSH: Received control message: 'PUSH_REPLY,redirect-gateway def1,dhcp-option DNS 8.8.8.8,dhcp-option DNS 8.8.8.8,route 10.102.162.1,topology net30,ping 10,ping-restart 120,ifconfig 10.102.162.6 10.102.162.5' Sun Sep 23 19:14:41 2012 OPTIONS IMPORT: timers and/or timeouts modified Sun Sep 23 19:14:41 2012 OPTIONS IMPORT: --ifconfig/up options modified Sun Sep 23 19:14:41 2012 OPTIONS IMPORT: route options modified Sun Sep 23 19:14:41 2012 OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified Sun Sep 23 19:14:41 2012 ROUTE default_gateway=10.0.2.2 Sun Sep 23 19:14:41 2012 TUN/TAP device tun0 opened Sun Sep 23 19:14:41 2012 TUN/TAP TX queue length set to 100 Sun Sep 23 19:14:41 2012 /sbin/ifconfig tun0 10.102.162.6 pointopoint 10.102.162.5 mtu 1500 Sun Sep 23 19:14:41 2012 /sbin/route add -net 192.162.102.162 netmask 255.255.255.255 gw 10.0.2.2 Sun Sep 23 19:14:41 2012 /sbin/route add -net 0.0.0.0 netmask 128.0.0.0 gw 10.102.162.5 Sun Sep 23 19:14:41 2012 /sbin/route add -net 128.0.0.0 netmask 128.0.0.0 gw 10.102.162.5 Sun Sep 23 19:14:41 2012 /sbin/route add -net 10.102.162.1 netmask 255.255.255.255 gw 10.102.162.5 Sun Sep 23 19:14:41 2012 Initialization Sequence Completed

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  • More CPU cores may not always lead to better performance – MAXDOP and query memory distribution in spotlight

    - by sqlworkshops
    More hardware normally delivers better performance, but there are exceptions where it can hinder performance. Understanding these exceptions and working around it is a major part of SQL Server performance tuning.   When a memory allocating query executes in parallel, SQL Server distributes memory to each task that is executing part of the query in parallel. In our example the sort operator that executes in parallel divides the memory across all tasks assuming even distribution of rows. Common memory allocating queries are that perform Sort and do Hash Match operations like Hash Join or Hash Aggregation or Hash Union.   In reality, how often are column values evenly distributed, think about an example; are employees working for your company distributed evenly across all the Zip codes or mainly concentrated in the headquarters? What happens when you sort result set based on Zip codes? Do all products in the catalog sell equally or are few products hot selling items?   One of my customers tested the below example on a 24 core server with various MAXDOP settings and here are the results:MAXDOP 1: CPU time = 1185 ms, elapsed time = 1188 msMAXDOP 4: CPU time = 1981 ms, elapsed time = 1568 msMAXDOP 8: CPU time = 1918 ms, elapsed time = 1619 msMAXDOP 12: CPU time = 2367 ms, elapsed time = 2258 msMAXDOP 16: CPU time = 2540 ms, elapsed time = 2579 msMAXDOP 20: CPU time = 2470 ms, elapsed time = 2534 msMAXDOP 0: CPU time = 2809 ms, elapsed time = 2721 ms - all 24 cores.In the above test, when the data was evenly distributed, the elapsed time of parallel query was always lower than serial query.   Why does the query get slower and slower with more CPU cores / higher MAXDOP? Maybe you can answer this question after reading the article; let me know: [email protected].   Well you get the point, let’s see an example.   The best way to learn is to practice. To create the below tables and reproduce the behavior, join the mailing list by using this link: www.sqlworkshops.com/ml and I will send you the table creation script.   Let’s update the Employees table with 49 out of 50 employees located in Zip code 2001. update Employees set Zip = EmployeeID / 400 + 1 where EmployeeID % 50 = 1 update Employees set Zip = 2001 where EmployeeID % 50 != 1 go update statistics Employees with fullscan go   Let’s create the temporary table #FireDrill with all possible Zip codes. drop table #FireDrill go create table #FireDrill (Zip int primary key) insert into #FireDrill select distinct Zip from Employees update statistics #FireDrill with fullscan go  Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --First serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) goThe query took 1011 ms to complete.   The execution plan shows the 77816 KB of memory was granted while the estimated rows were 799624.  No Sort Warnings in SQL Server Profiler.  Now let’s execute the query in parallel with MAXDOP 0. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 1912 ms to complete.  The execution plan shows the 79360 KB of memory was granted while the estimated rows were 799624.  The estimated number of rows between serial and parallel plan are the same. The parallel plan has slightly more memory granted due to additional overhead. Sort properties shows the rows are unevenly distributed over the 4 threads.   Sort Warnings in SQL Server Profiler.   Intermediate Summary: The reason for the higher duration with parallel plan was sort spill. This is due to uneven distribution of employees over Zip codes, especially concentration of 49 out of 50 employees in Zip code 2001. Now let’s update the Employees table and distribute employees evenly across all Zip codes.   update Employees set Zip = EmployeeID / 400 + 1 go update statistics Employees with fullscan go  Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --Serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) go   The query took 751 ms to complete.  The execution plan shows the 77816 KB of memory was granted while the estimated rows were 784707.  No Sort Warnings in SQL Server Profiler.   Now let’s execute the query in parallel with MAXDOP 0. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 661 ms to complete.  The execution plan shows the 79360 KB of memory was granted while the estimated rows were 784707.  Sort properties shows the rows are evenly distributed over the 4 threads. No Sort Warnings in SQL Server Profiler.    Intermediate Summary: When employees were distributed unevenly, concentrated on 1 Zip code, parallel sort spilled while serial sort performed well without spilling to tempdb. When the employees were distributed evenly across all Zip codes, parallel sort and serial sort did not spill to tempdb. This shows uneven data distribution may affect the performance of some parallel queries negatively. For detailed discussion of memory allocation, refer to webcasts available at www.sqlworkshops.com/webcasts.     Some of you might conclude from the above execution times that parallel query is not faster even when there is no spill. Below you can see when we are joining limited amount of Zip codes, parallel query will be fasted since it can use Bitmap Filtering.   Let’s update the Employees table with 49 out of 50 employees located in Zip code 2001. update Employees set Zip = EmployeeID / 400 + 1 where EmployeeID % 50 = 1 update Employees set Zip = 2001 where EmployeeID % 50 != 1 go update statistics Employees with fullscan go  Let’s create the temporary table #FireDrill with limited Zip codes. drop table #FireDrill go create table #FireDrill (Zip int primary key) insert into #FireDrill select distinct Zip       from Employees where Zip between 1800 and 2001 update statistics #FireDrill with fullscan go  Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --Serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) go The query took 989 ms to complete.  The execution plan shows the 77816 KB of memory was granted while the estimated rows were 785594. No Sort Warnings in SQL Server Profiler.  Now let’s execute the query in parallel with MAXDOP 0. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 1799 ms to complete.  The execution plan shows the 79360 KB of memory was granted while the estimated rows were 785594.  Sort Warnings in SQL Server Profiler.    The estimated number of rows between serial and parallel plan are the same. The parallel plan has slightly more memory granted due to additional overhead.  Intermediate Summary: The reason for the higher duration with parallel plan even with limited amount of Zip codes was sort spill. This is due to uneven distribution of employees over Zip codes, especially concentration of 49 out of 50 employees in Zip code 2001.   Now let’s update the Employees table and distribute employees evenly across all Zip codes. update Employees set Zip = EmployeeID / 400 + 1 go update statistics Employees with fullscan go Let’s execute the query serially with MAXDOP 1. --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --Serially with MAXDOP 1 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 1) go The query took 250  ms to complete.  The execution plan shows the 9016 KB of memory was granted while the estimated rows were 79973.8.  No Sort Warnings in SQL Server Profiler.  Now let’s execute the query in parallel with MAXDOP 0.  --Example provided by www.sqlworkshops.com --Execute query with uneven Zip code distribution --In parallel with MAXDOP 0 set statistics time on go declare @EmployeeID int, @EmployeeName varchar(48),@zip int select @EmployeeName = e.EmployeeName, @zip = e.Zip from Employees e       inner join #FireDrill fd on (e.Zip = fd.Zip)       order by e.Zip option (maxdop 0) go The query took 85 ms to complete.  The execution plan shows the 13152 KB of memory was granted while the estimated rows were 784707.  No Sort Warnings in SQL Server Profiler.    Here you see, parallel query is much faster than serial query since SQL Server is using Bitmap Filtering to eliminate rows before the hash join.   Parallel queries are very good for performance, but in some cases it can hinder performance. If one identifies the reason for these hindrances, then it is possible to get the best out of parallelism. I covered many aspects of monitoring and tuning parallel queries in webcasts (www.sqlworkshops.com/webcasts) and articles (www.sqlworkshops.com/articles). I suggest you to watch the webcasts and read the articles to better understand how to identify and tune parallel query performance issues.   Summary: One has to avoid sort spill over tempdb and the chances of spills are higher when a query executes in parallel with uneven data distribution. Parallel query brings its own advantage, reduced elapsed time and reduced work with Bitmap Filtering. So it is important to understand how to avoid spills over tempdb and when to execute a query in parallel.   I explain these concepts with detailed examples in my webcasts (www.sqlworkshops.com/webcasts), I recommend you to watch them. The best way to learn is to practice. To create the above tables and reproduce the behavior, join the mailing list at www.sqlworkshops.com/ml and I will send you the relevant SQL Scripts.   Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   Disclaimer and copyright information:This article refers to organizations and products that may be the trademarks or registered trademarks of their various owners. Copyright of this article belongs to R Meyyappan / www.sqlworkshops.com. You may freely use the ideas and concepts discussed in this article with acknowledgement (www.sqlworkshops.com), but you may not claim any of it as your own work. This article is for informational purposes only; you use any of the suggestions given here entirely at your own risk.   Register for the upcoming 3 Day Level 400 Microsoft SQL Server 2008 and SQL Server 2005 Performance Monitoring & Tuning Hands-on Workshop in London, United Kingdom during March 15-17, 2011, click here to register / Microsoft UK TechNet.These are hands-on workshops with a maximum of 12 participants and not lectures. For consulting engagements click here.   R Meyyappan [email protected] LinkedIn: http://at.linkedin.com/in/rmeyyappan  

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  • C#/.NET Little Wonders: The Joy of Anonymous Types

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. In the .NET 3 Framework, Microsoft introduced the concept of anonymous types, which provide a way to create a quick, compiler-generated types at the point of instantiation.  These may seem trivial, but are very handy for concisely creating lightweight, strongly-typed objects containing only read-only properties that can be used within a given scope. Creating an Anonymous Type In short, an anonymous type is a reference type that derives directly from object and is defined by its set of properties base on their names, number, types, and order given at initialization.  In addition to just holding these properties, it is also given appropriate overridden implementations for Equals() and GetHashCode() that take into account all of the properties to correctly perform property comparisons and hashing.  Also overridden is an implementation of ToString() which makes it easy to display the contents of an anonymous type instance in a fairly concise manner. To construct an anonymous type instance, you use basically the same initialization syntax as with a regular type.  So, for example, if we wanted to create an anonymous type to represent a particular point, we could do this: 1: var point = new { X = 13, Y = 7 }; Note the similarity between anonymous type initialization and regular initialization.  The main difference is that the compiler generates the type name and the properties (as readonly) based on the names and order provided, and inferring their types from the expressions they are assigned to. It is key to remember that all of those factors (number, names, types, order of properties) determine the anonymous type.  This is important, because while these two instances share the same anonymous type: 1: // same names, types, and order 2: var point1 = new { X = 13, Y = 7 }; 3: var point2 = new { X = 5, Y = 0 }; These similar ones do not: 1: var point3 = new { Y = 3, X = 5 }; // different order 2: var point4 = new { X = 3, Y = 5.0 }; // different type for Y 3: var point5 = new {MyX = 3, MyY = 5 }; // different names 4: var point6 = new { X = 1, Y = 2, Z = 3 }; // different count Limitations on Property Initialization Expressions The expression for a property in an anonymous type initialization cannot be null (though it can evaluate to null) or an anonymous function.  For example, the following are illegal: 1: // Null can't be used directly. Null reference of what type? 2: var cantUseNull = new { Value = null }; 3:  4: // Anonymous methods cannot be used. 5: var cantUseAnonymousFxn = new { Value = () => Console.WriteLine(“Can’t.”) }; Note that the restriction on null is just that you can’t use it directly as the expression, because otherwise how would it be able to determine the type?  You can, however, use it indirectly assigning a null expression such as a typed variable with the value null, or by casting null to a specific type: 1: string str = null; 2: var fineIndirectly = new { Value = str }; 3: var fineCast = new { Value = (string)null }; All of the examples above name the properties explicitly, but you can also implicitly name properties if they are being set from a property, field, or variable.  In these cases, when a field, property, or variable is used alone, and you don’t specify a property name assigned to it, the new property will have the same name.  For example: 1: int variable = 42; 2:  3: // creates two properties named varriable and Now 4: var implicitProperties = new { variable, DateTime.Now }; Is the same type as: 1: var explicitProperties = new { variable = variable, Now = DateTime.Now }; But this only works if you are using an existing field, variable, or property directly as the expression.  If you use a more complex expression then the name cannot be inferred: 1: // can't infer the name variable from variable * 2, must name explicitly 2: var wontWork = new { variable * 2, DateTime.Now }; In the example above, since we typed variable * 2, it is no longer just a variable and thus we would have to assign the property a name explicitly. ToString() on Anonymous Types One of the more trivial overrides that an anonymous type provides you is a ToString() method that prints the value of the anonymous type instance in much the same format as it was initialized (except actual values instead of expressions as appropriate of course). For example, if you had: 1: var point = new { X = 13, Y = 42 }; And then print it out: 1: Console.WriteLine(point.ToString()); You will get: 1: { X = 13, Y = 42 } While this isn’t necessarily the most stunning feature of anonymous types, it can be handy for debugging or logging values in a fairly easy to read format. Comparing Anonymous Type Instances Because anonymous types automatically create appropriate overrides of Equals() and GetHashCode() based on the underlying properties, we can reliably compare two instances or get hash codes.  For example, if we had the following 3 points: 1: var point1 = new { X = 1, Y = 2 }; 2: var point2 = new { X = 1, Y = 2 }; 3: var point3 = new { Y = 2, X = 1 }; If we compare point1 and point2 we’ll see that Equals() returns true because they overridden version of Equals() sees that the types are the same (same number, names, types, and order of properties) and that the values are the same.   In addition, because all equal objects should have the same hash code, we’ll see that the hash codes evaluate to the same as well: 1: // true, same type, same values 2: Console.WriteLine(point1.Equals(point2)); 3:  4: // true, equal anonymous type instances always have same hash code 5: Console.WriteLine(point1.GetHashCode() == point2.GetHashCode()); However, if we compare point2 and point3 we get false.  Even though the names, types, and values of the properties are the same, the order is not, thus they are two different types and cannot be compared (and thus return false).  And, since they are not equal objects (even though they have the same value) there is a good chance their hash codes are different as well (though not guaranteed): 1: // false, different types 2: Console.WriteLine(point2.Equals(point3)); 3:  4: // quite possibly false (was false on my machine) 5: Console.WriteLine(point2.GetHashCode() == point3.GetHashCode()); Using Anonymous Types Now that we’ve created instances of anonymous types, let’s actually use them.  The property names (whether implicit or explicit) are used to access the individual properties of the anonymous type.  The main thing, once again, to keep in mind is that the properties are readonly, so you cannot assign the properties a new value (note: this does not mean that instances referred to by a property are immutable – for more information check out C#/.NET Fundamentals: Returning Data Immutably in a Mutable World). Thus, if we have the following anonymous type instance: 1: var point = new { X = 13, Y = 42 }; We can get the properties as you’d expect: 1: Console.WriteLine(“The point is: ({0},{1})”, point.X, point.Y); But we cannot alter the property values: 1: // compiler error, properties are readonly 2: point.X = 99; Further, since the anonymous type name is only known by the compiler, there is no easy way to pass anonymous type instances outside of a given scope.  The only real choices are to pass them as object or dynamic.  But really that is not the intention of using anonymous types.  If you find yourself needing to pass an anonymous type outside of a given scope, you should really consider making a POCO (Plain Old CLR Type – i.e. a class that contains just properties to hold data with little/no business logic) instead. Given that, why use them at all?  Couldn’t you always just create a POCO to represent every anonymous type you needed?  Sure you could, but then you might litter your solution with many small POCO classes that have very localized uses. It turns out this is the key to when to use anonymous types to your advantage: when you just need a lightweight type in a local context to store intermediate results, consider an anonymous type – but when that result is more long-lived and used outside of the current scope, consider a POCO instead. So what do we mean by intermediate results in a local context?  Well, a classic example would be filtering down results from a LINQ expression.  For example, let’s say we had a List<Transaction>, where Transaction is defined something like: 1: public class Transaction 2: { 3: public string UserId { get; set; } 4: public DateTime At { get; set; } 5: public decimal Amount { get; set; } 6: // … 7: } And let’s say we had this data in our List<Transaction>: 1: var transactions = new List<Transaction> 2: { 3: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = 2200.00m }, 4: new Transaction { UserId = "Jim", At = DateTime.Now, Amount = -1100.00m }, 5: new Transaction { UserId = "Jim", At = DateTime.Now.AddDays(-1), Amount = 900.00m }, 6: new Transaction { UserId = "John", At = DateTime.Now.AddDays(-2), Amount = 300.00m }, 7: new Transaction { UserId = "John", At = DateTime.Now, Amount = -10.00m }, 8: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = 200.00m }, 9: new Transaction { UserId = "Jane", At = DateTime.Now, Amount = -50.00m }, 10: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = -100.00m }, 11: new Transaction { UserId = "Jaime", At = DateTime.Now.AddDays(-3), Amount = 300.00m }, 12: }; So let’s say we wanted to get the transactions for each day for each user.  That is, for each day we’d want to see the transactions each user performed.  We could do this very simply with a nice LINQ expression, without the need of creating any POCOs: 1: // group the transactions based on an anonymous type with properties UserId and Date: 2: byUserAndDay = transactions 3: .GroupBy(tx => new { tx.UserId, tx.At.Date }) 4: .OrderBy(grp => grp.Key.Date) 5: .ThenBy(grp => grp.Key.UserId); Now, those of you who have attempted to use custom classes as a grouping type before (such as GroupBy(), Distinct(), etc.) may have discovered the hard way that LINQ gets a lot of its speed by utilizing not on Equals(), but also GetHashCode() on the type you are grouping by.  Thus, when you use custom types for these purposes, you generally end up having to write custom Equals() and GetHashCode() implementations or you won’t get the results you were expecting (the default implementations of Equals() and GetHashCode() are reference equality and reference identity based respectively). As we said before, it turns out that anonymous types already do these critical overrides for you.  This makes them even more convenient to use!  Instead of creating a small POCO to handle this grouping, and then having to implement a custom Equals() and GetHashCode() every time, we can just take advantage of the fact that anonymous types automatically override these methods with appropriate implementations that take into account the values of all of the properties. Now, we can look at our results: 1: foreach (var group in byUserAndDay) 2: { 3: // the group’s Key is an instance of our anonymous type 4: Console.WriteLine("{0} on {1:MM/dd/yyyy} did:", group.Key.UserId, group.Key.Date); 5:  6: // each grouping contains a sequence of the items. 7: foreach (var tx in group) 8: { 9: Console.WriteLine("\t{0}", tx.Amount); 10: } 11: } And see: 1: Jaime on 06/18/2012 did: 2: -100.00 3: 300.00 4:  5: John on 06/19/2012 did: 6: 300.00 7:  8: Jim on 06/20/2012 did: 9: 900.00 10:  11: Jane on 06/21/2012 did: 12: 200.00 13: -50.00 14:  15: Jim on 06/21/2012 did: 16: 2200.00 17: -1100.00 18:  19: John on 06/21/2012 did: 20: -10.00 Again, sure we could have just built a POCO to do this, given it an appropriate Equals() and GetHashCode() method, but that would have bloated our code with so many extra lines and been more difficult to maintain if the properties change.  Summary Anonymous types are one of those Little Wonders of the .NET language that are perfect at exactly that time when you need a temporary type to hold a set of properties together for an intermediate result.  While they are not very useful beyond the scope in which they are defined, they are excellent in LINQ expressions as a way to create and us intermediary values for further expressions and analysis. Anonymous types are defined by the compiler based on the number, type, names, and order of properties created, and they automatically implement appropriate Equals() and GetHashCode() overrides (as well as ToString()) which makes them ideal for LINQ expressions where you need to create a set of properties to group, evaluate, etc. Technorati Tags: C#,CSharp,.NET,Little Wonders,Anonymous Types,LINQ

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  • The Inkremental Architect&acute;s Napkin - #4 - Make increments tangible

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/06/12/the-inkremental-architectacutes-napkin---4---make-increments-tangible.aspxThe driver of software development are increments, small increments, tiny increments. With an increment being a slice of the overall requirement scope thin enough to implement and get feedback from a product owner within 2 days max. Such an increment might concern Functionality or Quality.[1] To make such high frequency delivery of increments possible, the transition from talking to coding needs to be as easy as possible. A user story or some other documentation of what´s supposed to get implemented until tomorrow evening at latest is one side of the medal. The other is where to put the logic in all of the code base. To implement an increment, only logic statements are needed. Functionality like Quality are just about expressions and control flow statements. Think of Assembler code without the CALL/RET instructions. That´s all is needed. Forget about functions, forget about classes. To make a user happy none of that is really needed. It´s just about the right expressions and conditional executions paths plus some memory allocation. Automatic function inlining of compilers which makes it clear how unimportant functions are for delivering value to users at runtime. But why then are there functions? Because they were invented for optimization purposes. We need them for better Evolvability and Production Efficiency. Nothing more, nothing less. No software has become faster, more secure, more scalable, more functional because we gathered logic under the roof of a function or two or a thousand. Functions make logic easier to understand. Functions make us faster in producing logic. Functions make it easier to keep logic consistent. Functions help to conserve memory. That said, functions are important. They are even the pivotal element of software development. We can´t code without them - whether you write a function yourself or not. Because there´s always at least one function in play: the Entry Point of a program. In Ruby the simplest program looks like this:puts "Hello, world!" In C# more is necessary:class Program { public static void Main () { System.Console.Write("Hello, world!"); } } C# makes the Entry Point function explicit, not so Ruby. But still it´s there. So you can think of logic always running in some function. Which brings me back to increments: In order to make the transition from talking to code as easy as possible, it has to be crystal clear into which function you should put the logic. Product owners might be content once there is a sticky note a user story on the Scrum or Kanban board. But developers need an idea of what that sticky note means in term of functions. Because with a function in hand, with a signature to run tests against, they have something to focus on. All´s well once there is a function behind whose signature logic can be piled up. Then testing frameworks can be used to check if the logic is correct. Then practices like TDD can help to drive the implementation. That´s why most code katas define exactly how the API of a solution should look like. It´s a function, maybe two or three, not more. A requirement like “Write a function f which takes this as parameters and produces such and such output by doing x” makes a developer comfortable. Yes, there are all kinds of details to think about, like which algorithm or technology to use, or what kind of state and side effects to consider. Even a single function not only must deliver on Functionality, but also on Quality and Evolvability. Nevertheless, once it´s clear which function to put logic in, you have a tangible starting point. So, yes, what I´m suggesting is to find a single function to put all the logic in that´s necessary to deliver on a the requirements of an increment. Or to put it the other way around: Slice requirements in a way that each increment´s logic can be located under the roof of a single function. Entry points Of course, the logic of a software will always be spread across many, many functions. But there´s always an Entry Point. That´s the most important function for each increment, because that´s the root to put integration or even acceptance tests on. A batch program like the above hello-world application only has a single Entry Point. All logic is reached from there, regardless how deep it´s nested in classes. But a program with a user interface like this has at least two Entry Points: One is the main function called upon startup. The other is the button click event handler for “Show my score”. But maybe there are even more, like another Entry Point being a handler for the event fired when one of the choices gets selected; because then some logic could check if the button should be enabled because all questions got answered. Or another Entry Point for the logic to be executed when the program is close; because then the choices made should be persisted. You see, an Entry Point to me is a function which gets triggered by the user of a software. With batch programs that´s the main function. With GUI programs on the desktop that´s event handlers. With web programs that´s handlers for URL routes. And my basic suggestion to help you with slicing requirements for Spinning is: Slice them in a way so that each increment is related to only one Entry Point function.[2] Entry Points are the “outer functions” of a program. That´s where the environment triggers behavior. That´s where hardware meets software. Entry points always get called because something happened to hardware state, e.g. a key was pressed, a mouse button clicked, the system timer ticked, data arrived over a wire.[3] Viewed from the outside, software is just a collection of Entry Point functions made accessible via buttons to press, menu items to click, gestures, URLs to open, keys to enter. Collections of batch processors I´d thus say, we haven´t moved forward since the early days of software development. We´re still writing batch programs. Forget about “event-driven programming” with its fancy GUI applications. Software is just a collection of batch processors. Earlier it was just one per program, today it´s hundreds we bundle up into applications. Each batch processor is represented by an Entry Point as its root that works on a number of resources from which it reads data to process and to which it writes results. These resources can be the keyboard or main memory or a hard disk or a communication line or a display. Together many batch processors - large and small - form applications the user perceives as a single whole: Software development that way becomes quite simple: just implement one batch processor after another. Well, at least in principle ;-) Features Each batch processor entered through an Entry Point delivers value to the user. It´s an increment. Sometimes its logic is trivial, sometimes it´s very complex. Regardless, each Entry Point represents an increment. An Entry Point implemented thus is a step forward in terms of Agility. At the same time it´s a tangible unit for developers. Therefore, identifying the more or less numerous batch processors in a software system is a rewarding task for product owners and developers alike. That´s where user stories meet code. In this example the user story translates to the Entry Point triggered by clicking the login button on a dialog like this: The batch then retrieves what has been entered via keyboard, loads data from a user store, and finally outputs some kind of response on the screen, e.g. by displaying an error message or showing the next dialog. This is all very simple, but you see, there is not just one thing happening, but several. Get input (email address, password) Load user for email address If user not found report error Check password Hash password Compare hash to hash stored in user Show next dialog Viewed from 10,000 feet it´s all done by the Entry Point function. And of course that´s technically possible. It´s just a bunch of logic and calling a couple of API functions. However, I suggest to take these steps as distinct aspects of the overall requirement described by the user story. Such aspects of requirements I call Features. Features too are increments. Each provides some (small) value of its own to the user. Each can be checked individually by a product owner. Instead of implementing all the logic behind the Login() entry point at once you can move forward increment by increment, e.g. First implement the dialog, let the user enter any credentials, and log him/her in without any checks. Features 1 and 4. Then hard code a single user and check the email address. Features 2 and 2.1. Then check password without hashing it (or use a very simple hash like the length of the password). Features 3. and 3.2 Replace hard coded user with a persistent user directoy, but a very simple one, e.g. a CSV file. Refinement of feature 2. Calculate the real hash for the password. Feature 3.1. Switch to the final user directory technology. Each feature provides an opportunity to deliver results in a short amount of time and get feedback. If you´re in doubt whether you can implement the whole entry point function until tomorrow night, then just go for a couple of features or even just one. That´s also why I think, you should strive for wrapping feature logic into a function of its own. It´s a matter of Evolvability and Production Efficiency. A function per feature makes the code more readable, since the language of requirements analysis and design is carried over into implementation. It makes it easier to apply changes to features because it´s clear where their logic is located. And finally, of course, it lets you re-use features in different context (read: increments). Feature functions make it easier for you to think of features as Spinning increments, to implement them independently, to let the product owner check them for acceptance individually. Increments consist of features, entry point functions consist of feature functions. So you can view software as a hierarchy of requirements from broad to thin which map to a hierarchy of functions - with entry points at the top.   I like this image of software as a self-similar structure on many levels of abstraction where requirements and code match each other. That to me is true agile design: the core tenet of Agility to move forward in increments is carried over into implementation. Increments on paper are retained in code. This way developers can easily relate to product owners. Elusive and fuzzy requirements are not tangible. Software production is moving forward through requirements one increment at a time, and one function at a time. In closing Product owners and developers are different - but they need to work together towards a shared goal: working software. So their notions of software need to be made compatible, they need to be connected. The increments of the product owner - user stories and features - need to be mapped straightforwardly to something which is relevant to developers. To me that´s functions. Yes, functions, not classes nor components nor micro services. We´re talking about behavior, actions, activities, processes. Their natural representation is a function. Something has to be done. Logic has to be executed. That´s the purpose of functions. Later, classes and other containers are needed to stay on top of a growing amount of logic. But to connect developers and product owners functions are the appropriate glue. Functions which represent increments. Can there always be such a small increment be found to deliver until tomorrow evening? I boldly say yes. Yes, it´s always possible. But maybe you´ve to start thinking differently. Maybe the product owner needs to start thinking differently. Completion is not the goal anymore. Neither is checking the delivery of an increment through the user interface of a software. Product owners need to become comfortable using test beds for certain features. If it´s hard to slice requirements thin enough for Spinning the reason is too little knowledge of something. Maybe you don´t yet understand the problem domain well enough? Maybe you don´t yet feel comfortable with some tool or technology? Then it´s time to acknowledge this fact. Be honest about your not knowing. And instead of trying to deliver as a craftsman officially become a researcher. Research an check back with the product owner every day - until your understanding has grown to a level where you are able to define the next Spinning increment. ? Sometimes even thin requirement slices will cover several Entry Points, like “Add validation of email addresses to all relevant dialogs.” Validation then will it put into a dozen functons. Still, though, it´s important to determine which Entry Points exactly get affected. That´s much easier, if strive for keeping the number of Entry Points per increment to 1. ? If you like call Entry Point functions event handlers, because that´s what they are. They all handle events of some kind, whether that´s palpable in your code or note. A public void btnSave_Click(object sender, EventArgs e) {…} might look like an event handler to you, but public static void Main() {…} is one also - for then event “program started”. ?

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  • Why do browsers have so many possible exploits?

    - by Beau Martínez
    When browsing I am ocassionally given warnings about pages that host malware "that could damage my computer". I am seriously perplexed as to why, in 2010, browsers still have possible exploits and can be cracked. My question is "Why?". I'm assuming it's because of the quick development that occured in the browser wars which were unsufficiently tested, but I'm unsure. Surely WebKit would have patched all the issues in KHTML, or Gecko sorted out the flaws in Netscape's engine, and the IE coders sorted through their codebase to eliminate possible flaws? (Somewhat related: http://superuser.com/questions/117770/which-browser-is-the-most-secure-research-and-practically-based.)

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  • Funky mail sorting and grouping in Outlook 2007

    - by laurie
    In outlook 2007 I group mails in a folder by subject with mails in each subject group sorted by Received date (newest to oldest) This works fine; I tick 'Subject' and 'Show in groups' in the context menu of the folder's table header. Life is good. But the subject groups in the mail folder are sorted alphabetically. I would like the group which has the newest mail to be the first group. Similar to how the arrange by 'Conversation' works Can this be done? I'm not averse to an add-in/macro type solution if anyone can point me at examples of implementing custom sorting in Outlook

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  • joining text files with 600M+ lines

    - by dnkb
    I have two files huge.txt and small.txt. Huge has around 600M rows and it's 14Gigs, each line has four space separated words (tokens) and finally another space separated column with a number. Small has 150K rows with a size of ~3M, a space separated word and a number. Both Files are sorted using the sort command, with no extra options. The words in both files may include apostrophes (') and dashes (-). The deisred output would contain all columns from the huge.txt and the second column (the number) from small txt where the first word of huge.txt and the first word of small.txt match. My attemtpts below failed miserably with the following error: cat huge.txt|join -o 1.1 1.2 1.3 1.4 2.2 - small.txt > output.txt join: memory exhausted What I suspect is that the sorting order isn't right somehow even though the files are pre-sorted using: sort -k1 huge.unsorted.txt > huge.txt sort -k1 small.unsorted.txt > small.txt Problems seem to appear around words that have apostrophes (') or dashes (-). I also tried dictinoary sorting using the -d option bumping into the same error at the end. I see two ways out of this but don't know how to implement any of them. 1) Any tips how to sort the files in a way that the join command considers them to be sorted properly? 2) I was thinking of calculating MD5 or some other hashes of the strings to get rid of the apostrophes and dashes, and do the sorting and joining with the hashes instead of the strings themselves an dat the "translate" back the hashes to strings, but leave the numbers intact at the end of the lines. Since there would be only 150K hashes it's not that bad. What would be a good way to calculate individual hashes for each of the strings? Some AWK magic? See file samples at the end. Thank you! sample of huge.txt had stirred me to 46 had stirred my corruption 57 had stirred old emotions 55 had stirred something in 69 had stirred something within 40 sample of small.txt caley 114881 calf 2757974 calfed 137861 calfee 71143 calflora 154624 calfskin 148347 calgary 9416465 calgon's 94846

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  • Default sort order in Windows folder

    - by Florian Müller
    I am running Windows 7 and I have a folder "Dropbox" inside my Documents folder. However, every time I restart Explorer and enter this folder, it is sorted by mutation date. I'd like to have it default sorted by name, which is still default in all other folders, however not in this one. Please let me know if there is a way to define this properly! Thanks in advance! Note: I actually found out that this is in every folder or library now, not only in some folders. This is the standard sort behaviour when I open explorer the first time.

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  • function to org-sort by three (3) criteria: due date / priority / title

    - by lawlist
    Is anyone aware of an org-sort function / modification that can refile / organize a group of TODO so that it sorts them by three (3) criteria: first sort by due date, second sort by priority, and third sort by by title of the task? EDIT: If anyone can please help me to modify this so that undated TODO are sorted last, that would be greatly appreciated -- at the present time, undated TODO are not being sorted: ;; multiple sort (defun org-sort-multi (&rest sort-types) "Multiple sorts on a certain level of an outline tree, or plain list items. SORT-TYPES is a list where each entry is either a character or a cons pair (BOOL . CHAR), where BOOL is whether or not to sort case-sensitively, and CHAR is one of the characters defined in `org-sort-entries-or-items'. Entries are applied in back to front order. Example: To sort first by TODO status, then by priority, then by date, then alphabetically (case-sensitive) use the following call: (org-sort-multi '(?d ?p ?t (t . ?a)))" (interactive) (dolist (x (nreverse sort-types)) (when (char-valid-p x) (setq x (cons nil x))) (condition-case nil (org-sort-entries (car x) (cdr x)) (error nil)))) ;; sort current level (defun lawlist-sort (&rest sort-types) "Sort the current org level. SORT-TYPES is a list where each entry is either a character or a cons pair (BOOL . CHAR), where BOOL is whether or not to sort case-sensitively, and CHAR is one of the characters defined in `org-sort-entries-or-items'. Entries are applied in back to front order. Defaults to \"?o ?p\" which is sorted by TODO status, then by priority" (interactive) (when (equal mode-name "Org") (let ((sort-types (or sort-types (if (or (org-entry-get nil "TODO") (org-entry-get nil "PRIORITY")) '(?d ?t ?p) ;; date, time, priority '((nil . ?a)))))) (save-excursion (outline-up-heading 1) (let ((start (point)) end) (while (and (not (bobp)) (not (eobp)) (<= (point) start)) (condition-case nil (outline-forward-same-level 1) (error (outline-up-heading 1)))) (unless (> (point) start) (goto-char (point-max))) (setq end (point)) (goto-char start) (apply 'org-sort-multi sort-types) (goto-char end) (when (eobp) (forward-line -1)) (when (looking-at "^\\s-*$") ;; (delete-line) ) (goto-char start) ;; (dotimes (x ) (org-cycle)) )))))

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  • Thunderbird message sorting - wrong dates

    - by Unsigned
    Thunderbird 3 is having a problem with one of my IMAP accounts. When sorted by date, it displays 10-15 messages at the top (newest) when in fact they are very old message. (pre-2010, over a year old, some up to 6-7 years old) It's not game-breaking, but it is annoying, as I have to look past those to check for "new" messages. Is there any way to fix this? I'd considered re-downloading all the messages via IMAP, but that would take weeks (50,000 messages). When I open it, it displays the correct date, also when I use "View Source" the Date: header has the correct date (2009, 2006, etc). Is there any way to make Thunderbird realize that it should be sorted down with the rest of the 2006/2009 messages? None of my other IMAP accounts (many with the same host server) have this issue.

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