Search Results

Search found 4838 results on 194 pages for 'binary heap'.

Page 80/194 | < Previous Page | 76 77 78 79 80 81 82 83 84 85 86 87  | Next Page >

  • MySQL is hogging my server resources

    - by Reacen
    Does anyone have any idea of what can cause this weird behaviour and how I go about fixing it? This is all coming from MySQL only (both RAM and CPU usage), for about 10 minutes after I reboot my Java game server (that has a pool of 256 connections). There are not that many queries and I think it may be more of a MySQL misconfiguration problem. My server: 3.20 GHz * 6 core / 24 GB RAM / 64 bit Windows Server 2003. My game server: Java server, with 256 MySQL connections pool (MyISAM engine), about 500,000 accounts, and 9 million rows of game items in database and about 3,000 players are connected. After about 15 minutes of the game server reboot, the server resumes its stability and CPU usage drop down to 1% ~ 5% and memory to 6 GB. Here is a copy of my MySQL configuration. Also, any advice about my MySQL configuration will be appreciated. I really set it up almost at random. # Example MySQL config file for very large systems. # # This is for a large system with memory of 1G-2G where the system runs mainly # MySQL. # # You can copy this file to # /etc/my.cnf to set global options, # mysql-data-dir/my.cnf to set server-specific options (in this # installation this directory is C:\mysql\data) or # ~/.my.cnf to set user-specific options. # # In this file, you can use all long options that a program supports. # If you want to know which options a program supports, run the program # with the "--help" option. # The following options will be passed to all MySQL clients [client] #password = your_password port = 3306 socket = /tmp/mysql.sock # Here follows entries for some specific programs # The MySQL server [mysqld] #log=c:\mysql.log port = 3306 socket = /tmp/mysql.sock skip-locking key_buffer_size = 2572M max_allowed_packet = 64M table_open_cache = 512 sort_buffer_size = 128M read_buffer_size = 128M read_rnd_buffer_size = 128M myisam_sort_buffer_size = 500M thread_cache_size = 32 query_cache_size = 1948M # Try number of CPU's*2 for thread_concurrency thread_concurrency = 12 max_connections = 5000 # Don't listen on a TCP/IP port at all. This can be a security enhancement, # if all processes that need to connect to mysqld run on the same host. # All interaction with mysqld must be made via Unix sockets or named pipes. # Note that using this option without enabling named pipes on Windows # (via the "enable-named-pipe" option) will render mysqld useless! # #skip-networking # Replication Master Server (default) # binary logging is required for replication log-bin=mysql-bin # required unique id between 1 and 2^32 - 1 # defaults to 1 if master-host is not set # but will not function as a master if omitted server-id = 1 # Replication Slave (comment out master section to use this) # # To configure this host as a replication slave, you can choose between # two methods : # # 1) Use the CHANGE MASTER TO command (fully described in our manual) - # the syntax is: # # CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>, # MASTER_USER=<user>, MASTER_PASSWORD=<password> ; # # where you replace <host>, <user>, <password> by quoted strings and # <port> by the master's port number (3306 by default). # # Example: # # CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306, # MASTER_USER='joe', MASTER_PASSWORD='secret'; # # OR # # 2) Set the variables below. However, in case you choose this method, then # start replication for the first time (even unsuccessfully, for example # if you mistyped the password in master-password and the slave fails to # connect), the slave will create a master.info file, and any later # change in this file to the variables' values below will be ignored and # overridden by the content of the master.info file, unless you shutdown # the slave server, delete master.info and restart the slaver server. # For that reason, you may want to leave the lines below untouched # (commented) and instead use CHANGE MASTER TO (see above) # # required unique id between 2 and 2^32 - 1 # (and different from the master) # defaults to 2 if master-host is set # but will not function as a slave if omitted #server-id = 2 # # The replication master for this slave - required #master-host = <hostname> # # The username the slave will use for authentication when connecting # to the master - required #master-user = <username> # # The password the slave will authenticate with when connecting to # the master - required #master-password = <password> # # The port the master is listening on. # optional - defaults to 3306 #master-port = <port> # # binary logging - not required for slaves, but recommended #log-bin=mysql-bin # # binary logging format - mixed recommended #binlog_format=mixed # Point the following paths to different dedicated disks #tmpdir = /tmp/ #log-update = /path-to-dedicated-directory/hostname # Uncomment the following if you are using InnoDB tables #innodb_data_home_dir = C:\mysql\data/ #innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend #innodb_log_group_home_dir = C:\mysql\data/ # You can set .._buffer_pool_size up to 50 - 80 % # of RAM but beware of setting memory usage too high #innodb_buffer_pool_size = 384M #innodb_additional_mem_pool_size = 20M # Set .._log_file_size to 25 % of buffer pool size #innodb_log_file_size = 100M #innodb_log_buffer_size = 8M #innodb_flush_log_at_trx_commit = 1 #innodb_lock_wait_timeout = 50 [mysqldump] quick max_allowed_packet = 64M [mysql] no-auto-rehash # Remove the next comment character if you are not familiar with SQL #safe-updates [myisamchk] key_buffer_size = 256M sort_buffer_size = 256M read_buffer = 8M write_buffer = 8M [mysqlhotcopy] interactive-timeout

    Read the article

  • Declaring variables with New DataSet vs DataSet

    - by eych
    What is the impact of creating variables using: Dim ds as New DataSet ds = GetActualData() where GetActualData() also creates a New DataSet and returns it? Does the original empty DataSet that was 'New'ed just get left in the Heap? What if this kind of code was in many places? Would that affect the ASP.NET process and cause it to recycle sooner?

    Read the article

  • My block is not retaining some of its objects

    - by Drew Crawford
    From the Blocks documentation: In a reference-counted environment, by default when you reference an Objective-C object within a block, it is retained. This is true even if you simply reference an instance variable of the object. I am trying to implement a completion handler pattern, where a block is given to an object before the work is performed and the block is executed by the receiver after the work is performed. Since I am being a good memory citizen, the block should own the objects it references in the completion handler and then they will be released when the block goes out of scope. I know enough to know that I must copy the block to move it to the heap since the block will survive the stack scope in which it was declared. However, one of my objects is getting deallocated unexpectedly. After some playing around, it appears that certain objects are not retained when the block is copied to the heap, while other objects are. I am not sure what I am doing wrong. Here's the smallest test case I can produce: typedef void (^ActionBlock)(UIView*); In the scope of some method: NSObject *o = [[[NSObject alloc] init] autorelease]; mailViewController = [[[MFMailComposeViewController alloc] init] autorelease]; NSLog(@"o's retain count is %d",[o retainCount]); NSLog(@"mailViewController's retain count is %d",[mailViewController retainCount]); ActionBlock myBlock = ^(UIView *view) { [mailViewController setCcRecipients:[NSArray arrayWithObjects:@"[email protected]",nil]]; [o class]; }; NSLog(@"mailViewController's retain count after the block is %d",[mailViewController retainCount]); NSLog(@"o's retain count after the block is %d",[o retainCount]); Block_copy(myBlock); NSLog(@"o's retain count after the copy is %d",[o retainCount]); NSLog(@"mailViewController's retain count after the copy is %d",[mailViewController retainCount]); I expect both objects to be retained by the block at some point, and I certainly expect their retain counts to be identical. Instead, I get this output: o's retain count is 1 mailViewController's retain count is 1 mailViewController's retain count after the block is 1 o's retain count after the block is 1 o's retain count after the copy is 2 mailViewController's retain count after the copy is 1 o (subclass of NSObject) is getting retained properly and will not go out of scope. However mailViewController is not retained and will be deallocated before the block is run, causing a crash.

    Read the article

  • Trouble recovering MySQL InnoDB database after server crash

    - by Andy Shinn
    I had a server crash due to a broken iSCSI link (the filesystem went into read-only mode). After repairing the link and rebooting the machine (CentOS 5 / MySQL 5.1), the MySQL server would not start and gave the following error: 100603 19:11:46 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql InnoDB: The log sequence number in ibdata files does not match InnoDB: the log sequence number in the ib_logfiles! 100603 19:11:46 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... InnoDB: Warning: database page corruption or a failed InnoDB: file read of page 112541. InnoDB: Trying to recover it from the doublewrite buffer. InnoDB: Dump of the page: 100603 19:11:46 InnoDB: Page dump in ascii and hex (16384 bytes): lots of binary data 100603 19:11:46 InnoDB: Page checksum 953720272, prior-to-4.0.14-form checksum 2641912043 InnoDB: stored checksum 617821918, prior-to-4.0.14-form stored checksum 2080617765 InnoDB: Page lsn 115 2632899642, low 4 bytes of lsn at page end 2641594600 InnoDB: Page number (if stored to page already) 112541, InnoDB: space id (if created with = MySQL-4.1.1 and stored already) 0 InnoDB: Page may be an index page where index id is 0 616 InnoDB: Dump of corresponding page in doublewrite buffer: 100603 19:11:46 InnoDB: Page dump in ascii and hex (16384 bytes): more binary data 100603 19:11:46 InnoDB: Page checksum 908374788, prior-to-4.0.14-form checksum 824841363 InnoDB: stored checksum 912869634, prior-to-4.0.14-form stored checksum 2210927931 InnoDB: Page lsn 115 2635312169, low 4 bytes of lsn at page end 2633173354 InnoDB: Page number (if stored to page already) 112541, InnoDB: space id (if created with = MySQL-4.1.1 and stored already) 0 InnoDB: Page may be an index page where index id is 0 616 InnoDB: Also the page in the doublewrite buffer is corrupt. InnoDB: Cannot continue operation. InnoDB: You can try to recover the database with the my.cnf InnoDB: option: InnoDB: innodb_force_recovery=6 100603 19:11:46 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended Per the error message, I have tried setting set-variable=innodb_force_recovery=6 in the my.cnf to get to the data. This allows the MySQL server to start. But when I try to do a mysqldump of the database or a SELECT * INTO OUTFILE "filename" FROM broken_table; it seems to endlessly just export the same line over and over again. I have also tried http://code.google.com/p/innodb-tools/. But this tool fails with an error that 'blob' type is not supported. If I try to access the data using the PHP application it crashes MySQL: `100603 19:19:19 - mysqld got signal 11 ; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=8384512 read_buffer_size=131072 max_used_connections=2 max_threads=151 threads_connected=2 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 338317 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. thd: 0x15d33f0 Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... stack_bottom = 0x453aff00 thread_stack 0x40000 /usr/libexec/mysqld(my_print_stacktrace+0x24) [0x874364] /usr/libexec/mysqld(handle_segfault+0x346) [0x5c9166] /lib64/libpthread.so.0 [0x3a6e40eb10] /usr/libexec/mysqld(rec_get_offsets_func+0x30) [0x7cc310] /usr/libexec/mysqld [0x7674d8] /usr/libexec/mysqld(btr_search_info_update_slow+0x638) [0x768d48] /usr/libexec/mysqld(btr_cur_search_to_nth_level+0xc7d) [0x75f86d] /usr/libexec/mysqld [0x7dd1c1] /usr/libexec/mysqld(row_search_for_mysql+0x18b0) [0x7e03d0] /usr/libexec/mysqld(ha_innobase::general_fetch(unsigned char*, unsigned int, unsigned int)+0x7c) [0x7526fc] /usr/libexec/mysqld(handler::read_multi_range_next(st_key_multi_range**)+0x29) [0x6aed09] /usr/libexec/mysqld(QUICK_RANGE_SELECT::get_next()+0x194) [0x69a964] /usr/libexec/mysqld [0x6aafe9] /usr/libexec/mysqld(sub_select(JOIN*, st_join_table*, bool)+0x56) [0x635196] /usr/libexec/mysqld [0x63f9cd] /usr/libexec/mysqld(JOIN::exec()+0x950) [0x6497c0] /usr/libexec/mysqld(mysql_select(THD*, Item*, TABLE_LIST*, unsigned int, List&, Item*, unsigned int, st_order*, st_order*, Item*, st_order*, unsign ed long long, select_result*, st_select_lex_unit*, st_select_lex*)+0x17b) [0x64b34b] /usr/libexec/mysqld(handle_select(THD*, st_lex*, select_result*, unsigned long)+0x169) [0x64bc79] /usr/libexec/mysqld [0x5d34b6] /usr/libexec/mysqld(mysql_execute_command(THD*)+0x4e5) [0x5d6b45] /usr/libexec/mysqld(mysql_parse(THD*, char const*, unsigned int, char const)+0x211) [0x5dc321] /usr/libexec/mysqld(dispatch_command(enum_server_command, THD*, char*, unsigned int)+0x10b8) [0x5dd3f8] /usr/libexec/mysqld(do_command(THD*)+0xe6) [0x5dd9e6] /usr/libexec/mysqld(handle_one_connection+0x73d) [0x5d036d] /lib64/libpthread.so.0 [0x3a6e40673d] /lib64/libc.so.6(clone+0x6d) [0x3a6d4d3d1d] Trying to get some variables. Some pointers may be invalid and cause the dump to abort... thd-query at 0x15de5e0 = SELECT DISTINCT count(DISTINCT i.itemid) as rowscount,i.hostid FROM items i WHERE ((i.itemid BETWEEN 000000000000000 AND 0999999 99999999)) AND i.type<9 AND (i.hostid IN (10017,10047,10050,10054,10056,10059,10062,10063,10064,10065,10066,10067,10068,10069,10070,10071,10072,10073,100 74,10075,10076,10077,10078,10079,10080,10081,10082,10084,10088,10089,10090,10091,10092,10093,10094,10095,10096,10097,10098,10099,10100,10101,10102,10103,10 104,10105,10106,10107,10108,10109)) GROUP BY i.hostid thd-thread_id=3 thd-killed=NOT_KILLED The manual page at contains information that should help you find out what is causing the crash. 100603 19:19:19 mysqld_safe Number of processes running now: 0 100603 19:19:19 mysqld_safe mysqld restarted` Before recovering form an older backup as a last resort I am looking for anymore suggestions. Thanks!

    Read the article

  • Sun permgen & JRockit garbage collection

    - by Striker
    In the Sun JVM, classes that are loaded by the class loader are put in permgen space and never gc'd. (Unless the class loader goes out of scope) It's my understanding that JRockit puts that same data on the heap instead. Is that data then subject to garbage collection? Thanks.

    Read the article

  • Can't log in via SSH to any accounts set to use /bin/bash as a default shell

    - by Gui Ambros
    I'm trying to install bash as the default shell on a ARM Linux running on an embedded device (Synology DS212+ NAS). But there's something really wrong, and I can't figure out what it is. Symptoms: 1) Root has /bin/bash as default shell, and can log in normally via SSH: $ grep root /etc/passwd root:x:0:0:root:/root:/bin/bash $ ssh root@NAS root@NAS's password: Last login: Sun Dec 16 14:06:56 2012 from desktop # 2) joeuser has /bin/bash as default shell, and receives "Permission denied" when trying to log in via SSH: $ grep joeuser /etc/passwd joeuser:x:1029:100:Joe User:/home/joeuser:/bin/bash $ ssh joeuser@localhost joeuser@NAS's password: Last login: Sun Dec 16 14:07:22 2012 from desktop Permission denied, please try again. Connection to localhost closed. 3) changing joeuser's shell back to /bin/sh: $ grep joeuser /etc/passwd joeuser:x:1029:100:Joe User:/home/joeuser:/bin/sh $ ssh joeuser@localhost Last login: Sun Dec 16 15:50:52 2012 from localhost $ To make things even more strange, I can log in as joeuser using /bin/bash using the serial console (!). Also a su - joeuser as root works fine, so the bash binary itself is working fine. In an act of despair, I changed joeuser's uid to 0 on /etc/passwd, but also didn't work, so it doesn't seem to be anything permission related. Seems that bash is doing some extra checking that sshd didn't like, and blocking the connections for non-root users. Maybe some sort of sanity checking - or terminal emulation - that is triggering the SIGCHLD, but only when called via ssh. I already went through every single item on sshd_config, and also put SSHD in debug mode, but didn't find anything strange. Here's my /etc/ssh/sshd_config: LogLevel DEBUG LoginGraceTime 2m PermitRootLogin yes RSAAuthentication yes PubkeyAuthentication yes AuthorizedKeysFile %h/.ssh/authorized_keys ChallengeResponseAuthentication no UsePAM yes AllowTcpForwarding no ChrootDirectory none Subsystem sftp internal-sftp -f DAEMON -u 000 And here's the output from /usr/syno/sbin/sshd -d, showing the failed attempt of joeuser trying to log in, with /bin/bash as the shell: debug1: Config token is loglevel debug1: Config token is logingracetime debug1: Config token is permitrootlogin debug1: Config token is rsaauthentication debug1: Config token is pubkeyauthentication debug1: Config token is authorizedkeysfile debug1: Config token is challengeresponseauthentication debug1: Config token is usepam debug1: Config token is allowtcpforwarding debug1: Config token is chrootdirectory debug1: Config token is subsystem debug1: HPN Buffer Size: 87380 debug1: sshd version OpenSSH_5.8p1-hpn13v11 debug1: read PEM private key done: type RSA debug1: private host key: #0 type 1 RSA debug1: read PEM private key done: type DSA debug1: private host key: #1 type 2 DSA debug1: read PEM private key done: type ECDSA debug1: private host key: #2 type 3 ECDSA debug1: rexec_argv[0]='/usr/syno/sbin/sshd' debug1: rexec_argv[1]='-d' Set /proc/self/oom_adj from 0 to -17 debug1: Bind to port 22 on ::. debug1: Server TCP RWIN socket size: 87380 debug1: HPN Buffer Size: 87380 Server listening on :: port 22. debug1: Bind to port 22 on 0.0.0.0. debug1: Server TCP RWIN socket size: 87380 debug1: HPN Buffer Size: 87380 Server listening on 0.0.0.0 port 22. debug1: Server will not fork when running in debugging mode. debug1: rexec start in 6 out 6 newsock 6 pipe -1 sock 9 debug1: inetd sockets after dupping: 4, 4 Connection from 127.0.0.1 port 52212 debug1: HPN Disabled: 0, HPN Buffer Size: 87380 debug1: Client protocol version 2.0; client software version OpenSSH_5.8p1-hpn13v11 SSH: Server;Ltype: Version;Remote: 127.0.0.1-52212;Protocol: 2.0;Client: OpenSSH_5.8p1-hpn13v11 debug1: match: OpenSSH_5.8p1-hpn13v11 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.8p1-hpn13v11 debug1: permanently_set_uid: 1024/100 debug1: MYFLAG IS 1 debug1: list_hostkey_types: ssh-rsa,ssh-dss,ecdsa-sha2-nistp256 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: AUTH STATE IS 0 debug1: REQUESTED ENC.NAME is 'aes128-ctr' debug1: kex: client->server aes128-ctr hmac-md5 none SSH: Server;Ltype: Kex;Remote: 127.0.0.1-52212;Enc: aes128-ctr;MAC: hmac-md5;Comp: none debug1: REQUESTED ENC.NAME is 'aes128-ctr' debug1: kex: server->client aes128-ctr hmac-md5 none debug1: expecting SSH2_MSG_KEX_ECDH_INIT debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: KEX done debug1: userauth-request for user joeuser service ssh-connection method none SSH: Server;Ltype: Authname;Remote: 127.0.0.1-52212;Name: joeuser debug1: attempt 0 failures 0 debug1: Config token is loglevel debug1: Config token is logingracetime debug1: Config token is permitrootlogin debug1: Config token is rsaauthentication debug1: Config token is pubkeyauthentication debug1: Config token is authorizedkeysfile debug1: Config token is challengeresponseauthentication debug1: Config token is usepam debug1: Config token is allowtcpforwarding debug1: Config token is chrootdirectory debug1: Config token is subsystem debug1: PAM: initializing for "joeuser" debug1: PAM: setting PAM_RHOST to "localhost" debug1: PAM: setting PAM_TTY to "ssh" debug1: userauth-request for user joeuser service ssh-connection method password debug1: attempt 1 failures 0 debug1: do_pam_account: called Accepted password for joeuser from 127.0.0.1 port 52212 ssh2 debug1: monitor_child_preauth: joeuser has been authenticated by privileged process debug1: PAM: establishing credentials User child is on pid 9129 debug1: Entering interactive session for SSH2. debug1: server_init_dispatch_20 debug1: server_input_channel_open: ctype session rchan 0 win 65536 max 16384 debug1: input_session_request debug1: channel 0: new [server-session] debug1: session_new: session 0 debug1: session_open: channel 0 debug1: session_open: session 0: link with channel 0 debug1: server_input_channel_open: confirm session debug1: server_input_global_request: rtype [email protected] want_reply 0 debug1: server_input_channel_req: channel 0 request pty-req reply 1 debug1: session_by_channel: session 0 channel 0 debug1: session_input_channel_req: session 0 req pty-req debug1: Allocating pty. debug1: session_new: session 0 debug1: session_pty_req: session 0 alloc /dev/pts/1 debug1: server_input_channel_req: channel 0 request shell reply 1 debug1: session_by_channel: session 0 channel 0 debug1: session_input_channel_req: session 0 req shell debug1: Setting controlling tty using TIOCSCTTY. debug1: Received SIGCHLD. debug1: session_by_pid: pid 9130 debug1: session_exit_message: session 0 channel 0 pid 9130 debug1: session_exit_message: release channel 0 debug1: session_by_tty: session 0 tty /dev/pts/1 debug1: session_pty_cleanup: session 0 release /dev/pts/1 Received disconnect from 127.0.0.1: 11: disconnected by user debug1: do_cleanup debug1: do_cleanup debug1: PAM: cleanup debug1: PAM: closing session debug1: PAM: deleting credentials Here you have the full output of sshd -dd, together with ssh -vv. Bash: # bash --version GNU bash, version 3.2.49(1)-release (arm-none-linux-gnueabi) Copyright (C) 2007 Free Software Foundation, Inc. The bash binary was cross compiled from source. I also tried using a pre-compiled binary from the Optware distribution, but had the exact same problem. I checked for missing shared libraries using objdump -x, but they're all there. Any ideas what could be causing this "Permission denied, please try again."? I'm almost diving in the bash source code to investigate, but trying to avoid hours chasing something that may be silly.

    Read the article

  • How to implement continuations?

    - by Kyle Cronin
    I'm working on a Scheme interpreter written in C. Currently it uses the C runtime stack as its own stack, which is presenting a minor problem with implementing continuations. My current solution is manual copying of the C stack to the heap then copying it back when needed. Aside from not being standard C, this solution is hardly ideal. What is the simplest way to implement continuations for Scheme in C?

    Read the article

  • what is the reason of Invalid Address specified to RtlFreeHeap

    - by carl
    the develop environment is vs2008, the language is c++, when I release the problem,at beginning it run with out problem but after several minutes it stop and show error like that : HEAP[guessModel.exe]: Invalid Address specified to RtlFreeHeap( 003E0000, 7D7C737B ). who can tell me the reason of the error. thank you very much.

    Read the article

  • Javascript running in facebox window

    - by Rudiger
    I'm modifying a website to have a pop up box appear when a user rates something prompting the user to login. Unfortunately the login process is something that I don't control and it uses a whole heap of javascript and redirects to do it and it seems that the javascript is failing. Can javascript run in the modal box or is there a way around this?

    Read the article

  • Experience of moving to 64 bit JVM

    - by Fazal
    Our company is planning to move to 64 bit JVM in order to get away from 2 GB maximum heap size limit. Google gave me very mixed results about 64 bit JVM performance. Has anyone tried moving to 64 bit java and share your experience

    Read the article

  • Memory layout of executable

    - by Ross
    Hi all, When loading an executable then segments like the code, data, bss and so on need to be placed in memory. I am just wondering, if someone could tell me where on a standard x86 for example the libc library is placed. Is that at the top or bottom of memory. My guess is at the bottom, close to the application code, ie., that would look something like this here: --------- 0x1000 Stack | V ^ | Heap ---------- Data + BSS ---------- App Code ---------- libc ---------- 0x0000 Thanks a lot, Ross

    Read the article

  • Strip OLE header information (MS Access / SQL Server)

    - by crimson13
    I have a C++ application that needs to support binary database content (images, etc). When using MS Access or MS SQL Server this data is wrapped inside an OLE object. How do I strip this OLE header information? Note that I can't just look for the beginning of a specific tag as the content can be png, jpg and a whole heap of other formats. Should I use something like COleDataObject?

    Read the article

  • Some questions about Vector in STL

    - by skydoor
    I have some questions about vector in STL to clarify..... Where are the objects in vector allocated? heap? does vector have boundary check? If the index out of the boundary, what error will happen? Why array is faster than vector? Is there any case in which vector is not applicable but array is a must?

    Read the article

  • Good Postgres graphical client for Windows

    - by alex
    The name pretty much says it all. Right now I'm using Squirrel - it crashes frequently and suffers from memory problems (I've tried increasing the heap size). I don't need anything particularly fancy or full-featured - just something that won't take up 2.4 GB of RAM to store a 1.5 million line, 8 column result set.

    Read the article

  • Memory efficient int-int dict in Python

    - by Bolo
    Hi, I need a memory efficient int-int dict in Python that would support the following operations in O(log n) time: d[k] = v # replace if present v = d[k] # None or a negative number if not present I need to hold ~250M pairs, so it really has to be tight. Do you happen to know a suitable implementation (Python 2.7)? EDIT Removed impossible requirement and other nonsense. Thanks, Craig and Kylotan! To rephrase. Here's a trivial int-int dictionary with 1M pairs: >>> import random, sys >>> from guppy import hpy >>> h = hpy() >>> h.setrelheap() >>> d = {} >>> for _ in xrange(1000000): ... d[random.randint(0, sys.maxint)] = random.randint(0, sys.maxint) ... >>> h.heap() Partition of a set of 1999530 objects. Total size = 49161112 bytes. Index Count % Size % Cumulative % Kind (class / dict of class) 0 1 0 25165960 51 25165960 51 dict (no owner) 1 1999521 100 23994252 49 49160212 100 int On average, a pair of integers uses 49 bytes. Here's an array of 2M integers: >>> import array, random, sys >>> from guppy import hpy >>> h = hpy() >>> h.setrelheap() >>> a = array.array('i') >>> for _ in xrange(2000000): ... a.append(random.randint(0, sys.maxint)) ... >>> h.heap() Partition of a set of 14 objects. Total size = 8001108 bytes. Index Count % Size % Cumulative % Kind (class / dict of class) 0 1 7 8000028 100 8000028 100 array.array On average, a pair of integers uses 8 bytes. I accept that 8 bytes/pair in a dictionary is rather hard to achieve in general. Rephrased question: is there a memory-efficient implementation of int-int dictionary that uses considerably less than 49 bytes/pair?

    Read the article

  • java dynamic memory allocation?

    - by JavaUser
    Hi, Why an object initialization using " new " keyword is called as dynamic memory allocation since compile time itself we know the memory needed for that object . Also please explain what happen when u do ClassA object = new ClassA(); in heap and stack . Thx

    Read the article

  • setting up Ubuntu 10.10 as paravirtualized guest in Xen on RHEL5 host - what kernel?

    - by kostmo
    I've discovered the tool ubuntu-vm-builder, which I've installed and then invoked on an Ubuntu workstation as: sudo vmbuilder xen ubuntu --suite maverick --flavour virtual --arch amd64 --mem=512 --rootsize 8192 This workstation is not the intended target host of the virtual machine, however; I would like to host the guest on a Red Hat Enterprise Linux 5 machine that is running Xen 3.0.3. The output of this command appears to be a folder named ubuntu-xen containing three files: tmpXXXXXX, a very large file which I assume is the root partition image tmpYYYYYY, a somewhat large file which I assume is the swap partition image xen.conf, a text file I have copied the xen.conf file to the RHEL server's /etc/xen directory under the new name newvm, adjusting the paths of tempXXXXXX and tempYYYYYYin the file after also copying them from my local workstation to the RHEL server. When I launch the Virtual Machine Manager virt-manager, I can see the newvm virtual machine listed underneath the Dom0 machine. When I try to start newvm, I get the error: Error starting domain: virDomainCreate() failed POST operation failed: (xend.err 'Error creating domain: Kernel image does not exist: None') Indeed, there exists an entry kernel = 'None' in the xen.conf file. How do I find out what the path of the kernel should be? Is this path supposed to be to a kernel stored on the local filesystem of the RHEL5 host, or is it supposed to be a path inside the guest image? I see that the vmbuilder command provides for a --xen-kernel option, along with a --xen-ramdisk option, but I'm not sure what to use for either. I think I should be able to get this to work, since Ubuntu is said to be supported as a Xen guest, even though the Xen 4.0.1 docs state support for only a limited set of distributions, Ubuntu excluded. Update 1 When running vmbuilder on my local workstation, I did observe an output line saying: Calling hook: install_kernel and later, output lines saying: update-initramfs: Generating /boot/initrd.img-2.6.35-23-virtual [...] run-parts: executing /etc/kernel/postinst.d/initramfs-tools 2.6.35-23-virtual /boot/vmlinuz-2.6.35-23-virtual So in the xen.conf file, I tried setting the lines: kernel = '/boot/vmlinuz-2.6.35-23-virtual' ramdisk = '/boot/initrd.img-2.6.35-23-virtual' When trying to start the VM, I got an error similar to last time: Error starting domain: virDomainCreate() failed POST operation failed: (xend.err 'Error creating domain: Kernel image does not exist: /boot/vmlinuz-2.6.35-23-virtual') This makes me think that the RHEL5 machine is looking for local files, rather than a file within the binary guest disk image. After running sudo updatedb on my workstation, neither of those files were found. If the vmbuilder tool had tried to install them, it must have failed. Update 2 I was able to extract the kernel and initrd images from the guest disk binary by mounting it: mkdir mnt_tmp sudo mount ubuntu-xen/tmpXXXXXX mnt_tmp/ -o loop cp mnt_tmp/boot/vmlinuz-2.6.35-23-virtual virtual_kernel_ubuntu cp mnt_tmp/boot/initrd.img-2.6.35-23-virtual virtual_initrd_ubuntu These two files I copied to the RHEL5 server, and edited the xen.conf file to point to them as kernel and ramdisk. With this done, I could "run" the newvm virtual machine from within virt-manager, but was met with the message Console Not Configured For Guest when I double clicked the entry to open the Virtual Machine Console. As suggested by a forum, I then added the line vfb = [ 'type=vnc' ] to the configuration file, recreated the virtual machine (a ~10 min process), and this time got the message: Connecting to console for guest This remained indefinitely; after selecting View - Serial Console, I found a kernel panic: [5442621.272173] Kernel panic - not syncing: Attempted to kill the idle task! [5442621.272179] Pid: 0, comm: swapper Tainted: G D 2.6.35-23-virtual #41-Ubuntu [5442621.272184] Call Trace: [5442621.272191] [<ffffffff815a1b81>] panic+0x90/0x111 [5442621.272199] [<ffffffff810652ee>] do_exit+0x3be/0x3f0 [5442621.272204] [<ffffffff815a5e20>] oops_end+0xb0/0xf0 [5442621.272211] [<ffffffff8100ddeb>] die+0x5b/0x90 [5442621.272216] [<ffffffff815a56c4>] do_trap+0xc4/0x170 [5442621.272221] [<ffffffff8100ba35>] do_invalid_op+0x95/0xb0 [5442621.272227] [<ffffffff8130851c>] ? intel_idle+0xac/0x180 [5442621.272232] [<ffffffff810072bf>] ? xen_restore_fl_direct_end+0x0/0x1 [5442621.272239] [<ffffffff815a48fe>] ? _raw_spin_unlock_irqrestore+0x1e/0x30 [5442621.272247] [<ffffffff8108dfb7>] ? tick_broadcast_oneshot_control+0xc7/0x120 [5442621.272253] [<ffffffff8100ad5b>] invalid_op+0x1b/0x20 [5442621.272259] [<ffffffff8130851c>] ? intel_idle+0xac/0x180 [5442621.272264] [<ffffffff813084e0>] ? intel_idle+0x70/0x180 [5442621.272269] [<ffffffff810072bf>] ? xen_restore_fl_direct_end+0x0/0x1 [5442621.272275] [<ffffffff8148a147>] cpuidle_idle_call+0xa7/0x140 [5442621.272281] [<ffffffff81008d93>] cpu_idle+0xb3/0x110 [5442621.272286] [<ffffffff815873aa>] rest_init+0x8a/0x90 [5442621.272291] [<ffffffff81b04c9d>] start_kernel+0x387/0x390 [5442621.272297] [<ffffffff81b04341>] x86_64_start_reservations+0x12c/0x130 [5442621.272303] [<ffffffff81b08002>] xen_start_kernel+0x55d/0x561 Update 3 I tried an i386 architecture instead of amd64, but got the same kernel panic. Also, it seems the Virtual Machine Manager pays attention to the format of the filename of the kernel; for the same kernel binary, I tried simply naming it vmlinuz-virtual, which threw out an error box about an invalid kernel. When I named it vmlinuz-2.6.35-23-virtual, it did not throw the error, but it did still result in the kernel panic shortly thereafter.

    Read the article

< Previous Page | 76 77 78 79 80 81 82 83 84 85 86 87  | Next Page >