Please whitelist cPanel in your adblocker so that you’re able to see our version release promotions, thanks!

The Community Forums

Interact with an entire community of cPanel & WHM users!

MySQL crashing --open-files-limit=50000 error / --skip-name-resolve

Discussion in 'Workarounds and Optimization' started by go4, Oct 21, 2015.

  1. go4

    go4 Member

    Joined:
    Sep 3, 2008
    Messages:
    9
    Likes Received:
    1
    Trophy Points:
    53
    Hi,

    Trying to track down MySQL issues on a VPS that has around 65 accounts, 78 databases. New to this so any help appreciated.

    So two things I can see (that may or may not be related).

    1. Open files limit

    Process Manager constantly shows

    Code:
    /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/xxxx.err --open-files-limit=50000 --pid-file=/var/lib/mysql/xxx.pid --socket=/var/lib/mysql/mysql.sock --port=xxx
    Could increase open files limit but it seems unlikely we should have 50000 open files?

    2. --skip-name-resolve errors

    We're getting LOTS of --skip-name-resolve errors in logs. Logs show intense periods where around 1000 entries appear with exactly the same timestamp, the first 500 showing [Warning] 'user' entry '-' ignored in --skip-name-resolve mode then another 500 corresponding db/user entries showing [Warning] 'db' entry...

    Code:
    151021 19:16:40 [Warning] 'user' entry 'xxx_xxx@xxx.xxx.com' ignored in --skip-name-resolve mode.
    + another 500 lines

    Code:
    151021 19:16:40 [Warning] 'db' entry 'xxx\xxx xxx@xxx.xxx.com' ignored in --skip-name-resolve mode.
    + another 500 lines

    Thanks.

    Server info
    Code:
    /etc/redhat-release:CentOS release 6.7 (Final)
    /usr/local/cpanel/version:11.52.0.17
    /var/cpanel/envtype:xen pv
    CPANEL=release
    Server version: Apache/2.2.27 (Unix)
    Server built:   Jul 17 2014 06:46:24
    Cpanel::Easy::Apache v3.26.0 rev9999
    PHP 5.4.30 (cli) (built: Jul 17 2014 06:54:51)
    Copyright (c) 1997-2014 The PHP Group
    Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies
        with the ionCube PHP Loader v4.6.1, Copyright (c) 2002-2014, by ionCube Ltd., and
        with Zend Guard Loader v3.3, Copyright (c) 1998-2013, by Zend Technologies
    mysql  Ver 14.14 Distrib 5.5.45, for Linux (x86_64) using readline 5.1
     
  2. cPanelMichael

    cPanelMichael Forums Analyst
    Staff Member

    Joined:
    Apr 11, 2011
    Messages:
    44,367
    Likes Received:
    1,855
    Trophy Points:
    363
    cPanel Access Level:
    Root Administrator
    Hello :)

    Do you notice any specific entries in the MySQL error log (/var/lib/mysql/$hostname.err) just before it crashes (other than the warning messages you posted)?

    Thank you.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  3. go4

    go4 Member

    Joined:
    Sep 3, 2008
    Messages:
    9
    Likes Received:
    1
    Trophy Points:
    53
    Thanks cPanelMichael,

    Appreciate your help.

    To clairify what I mean when I say crash: although from the frontend we're getting "Cannot connect to database" and everything going down the xxx.err log doesn't show a crash.

    What I can see in the log though is that instantly on restart those --skip-name-resolve ignored errors start up, hundreds of lines logging at the same second restart completes.

    Code:
    150927 19:25:09 mysqld_safe Number of processes running now: 0
    150927 19:25:12 mysqld_safe mysqld restarted
    150927 19:25:13 [Warning] 'THREAD_CONCURRENCY' is deprecated and will be removed in a future release.
    150927 19:25:13 [Note] Plugin 'FEDERATED' is disabled.
    150927 19:25:13 InnoDB: The InnoDB memory heap is disabled
    150927 19:25:13 InnoDB: Mutexes and rw_locks use GCC atomic builtins
    150927 19:25:13 InnoDB: Compressed tables use zlib 1.2.3
    150927 19:25:13 InnoDB: Using Linux native AIO
    150927 19:25:14 InnoDB: Initializing buffer pool, size = 128.0M
    150927 19:25:14 InnoDB: Completed initialization of buffer pool
    150927 19:25:14 InnoDB: highest supported file format is Barracuda.
    InnoDB: The log sequence number in ibdata files does not match
    InnoDB: the log sequence number in the ib_logfiles!
    150927 19:25:14  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...
    150927 19:25:23  InnoDB: Waiting for the background threads to start
    150927 19:25:24 InnoDB: 5.5.42 started; log sequence number 3135004108
    150927 19:25:24 [Note] Server hostname (bind-address): '0.0.0.0'; port: 3306
    150927 19:25:24 [Note]   - '0.0.0.0' resolves to '0.0.0.0';
    150927 19:25:24 [Note] Server socket created on IP: '0.0.0.0'.
    150927 19:25:24 [Warning] 'user' entry 'xx@xx' ignored in --skip-name-resolve mode.
    150927 19:25:24 [Warning] 'user' entry 'xx@xx' ignored in --skip-name-resolve mode.
    150927 19:25:24 [Warning] 'user' entry 'xx@x'x ignored in --skip-name-resolve mode.
    150927 19:25:24 [Warning] 'user' entry 'xx@xx' ignored in --skip-name-resolve mode.
    ...etc etc etc...
     
  4. anton_latvia

    anton_latvia Well-Known Member
    PartnerNOC

    Joined:
    May 11, 2004
    Messages:
    358
    Likes Received:
    4
    Trophy Points:
    168
    Location:
    Latvia
    cPanel Access Level:
    Root Administrator
    is that end? Does MySQL server operate normally afterwards? open-files-limits can be lowered.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
    #4 anton_latvia, Oct 27, 2015
    Last edited by a moderator: Oct 27, 2015
  5. go4

    go4 Member

    Joined:
    Sep 3, 2008
    Messages:
    9
    Likes Received:
    1
    Trophy Points:
    53
    Thanks anton,

    No afterwards we straight away get hundreds of those
    [Warning] 'user' entry 'xx@xx' ignored in --skip-name-resolve mode entries and then always in Process Manager

    Code:
    /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/xxx.com.err --open-files-limit=50000 --pid-file=/var/lib/mysql/xxx.com.pid --socket=/var/lib/mysql/mysql.sock --port=3306
     
  6. anton_latvia

    anton_latvia Well-Known Member
    PartnerNOC

    Joined:
    May 11, 2004
    Messages:
    358
    Likes Received:
    4
    Trophy Points:
    168
    Location:
    Latvia
    cPanel Access Level:
    Root Administrator
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
Loading...

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice