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PHP-FPM WARNING: [pool www] child xxxx exited on signal 11

Discussion in 'Nginx, PHP-FPM & MariaDB MySQL' started by negative, Dec 11, 2015.

  1. negative

    negative Member

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    I see these errors on php-fpm error log file.

    Code:
    [root@web log]# tail -f /var/log/php-fpm/www-error.log
    [10-Dec-2015 10:47:33] WARNING: [pool www] child 5022 exited on signal 11 (SIGSEGV) after 618.942788 seconds from start
    [10-Dec-2015 11:01:25] WARNING: [pool www] child 5774 exited on signal 11 (SIGSEGV) after 466.259136 seconds from start
    [10-Dec-2015 12:14:58] WARNING: [pool www] child 6885 exited on signal 11 (SIGSEGV) after 1318.445113 seconds from start
    [10-Dec-2015 12:43:04] WARNING: [pool www] child 7053 exited on signal 11 (SIGSEGV) after 2526.363851 seconds from start
    [10-Dec-2015 12:47:53] WARNING: [pool www] child 6906 exited on signal 11 (SIGSEGV) after 3289.430635 seconds from start
    [10-Dec-2015 12:52:07] WARNING: [pool www] child 7228 exited on signal 11 (SIGSEGV) after 2356.995685 seconds from start
    [10-Dec-2015 13:36:53] WARNING: [pool www] child 8052 exited on signal 11 (SIGSEGV) after 2656.729154 seconds from start
    [10-Dec-2015 14:13:25] WARNING: [pool www] child 9228 exited on signal 11 (SIGSEGV) after 1465.125126 seconds from start
    [10-Dec-2015 14:13:25] WARNING: [pool www] child 9203 exited on signal 11 (SIGSEGV) after 1465.174242 seconds from start
    My php-fpm.conf
    Code:
    pm = dynamic
    pm.max_children = 256
    ; Default Value: min_spare_servers + (max_spare_servers - min_spare_servers) / 2
    pm.start_servers = 40
    pm.min_spare_servers = 16
    pm.max_spare_servers = 64
    pm.max_requests = 1000
    Why live this errors and how will be fixed ? Thanks
     
  2. RoldanLT

    RoldanLT Well-Known Member

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    Your PHP-FPM config is not really cool :D
    How many CPU do you have on that server?
     
  3. negative

    negative Member

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    Hello :ROFLMAO:

    2x Intel(R) Xeon(R) CPU X5650 @ 2.67GHz Dedicated Server
    Total CPU count with HT : 24 (12 Psychical 12 Logical)

    Ram: 48GB DDR3 1333
     
  4. eva2000

    eva2000 Administrator Staff Member

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    Nginx 1.13.x
    MariaDB 5.5
    segfaults and settings too high

    Centmin Mod is provide as is, so short of scripted related bugs or issues, any further optimisation to the web stack components - nginx, php-fpm, mariadb mysql, csf firewall etc or web app specific configurations are left to the Centmin Mod user to deal with. So I do not provide any free support for such.

    Nginx 502 or 504 Bad Gateway Errors



    Bad gateway 502 /504 timeouts are usually related to Nginx timing out waiting on PHP-FPM to respond as PHP-FPM is overloaded or overwhelmed with requests, so may need to tune PHP-FPM values. It also maybe due to PHP-FPM in turn being queued and backed up waiting on MariaDB MySQL server to respond - so also need to look at MySQL.

    You'll need to tune your PHP-FPM settings and this is left up to end user to do but here's a thread for starters to enable php status page output outlined at PHP-FPM - CentminMod.com LEMP Nginx web stack for CentOS and PHP-FPM - pm.max_children | Centmin Mod Community which outlines the official PHP-FPM config documentation as well.

    Checking PHP-FPM etc logs



    You'll also need to check into your PHP-FPM, Nginx and MariaDB logs which you can find as outlined at How to troubleshoot Centmin Mod initial install issues

    Server logs include Nginx, PHP-FPM, MariaDB MySQL error logs as well as others. You can find your Centmin Mod install/menu logs at FAQ 7 and server logs at FAQ 19 at Centmin Mod FAQ (most up to date info in FAQ so always read that first). Spoiler tag below has info too but may not be up to date.

    Some of Centmin Mod's installed software will have their own access and error logs which maybe useful for diagnosing errors or give info, notes, or warning notices.

    Note: There's no support provided by me for diagnosing such errors which may occur for various reasons including misconfiguration of installed php/mysql scripts or applications.

    In SSH2 telnet you can use tail command to view the last X number of lines in the file.

    For example for viewing last 10 lines in the file for:

    For Nginx access and error logs:
    Code:
    tail -10 /usr/local/nginx/logs/access.log
    tail -10 /usr/local/nginx/logs/error.log
    
    For specific domainname.com access and error log:
    Code:
    tail -10 /home/nginx/domains/domainname.com/log/access.log
    tail -10 /home/nginx/domains/domainname.com/log/error.log
    
    For other system error logs located at /var/log:

    list /var/log files in ascending time order so the most recently modified files are at the bottom
    Code:
    ls -lhrt /var/log
    
    Code:
    total 2.7M
    -rw------- 1 root root 0 Aug 29 15:33 tallylog
    -rw------- 1 root root 0 Aug 29 15:33 spooler
    drwx------ 3 root root 4.0K Aug 29 15:35 samba
    drwxr-xr-x 2 root root 4.0K Aug 29 15:35 mail
    -rw-r--r-- 1 root 500 0 Oct 8 18:13 dmesg.old
    -rw------- 1 root 500 0 Oct 8 18:13 boot.log
    -rw-r--r-- 1 root 500 0 Oct 8 18:14 dmesg
    drwx------ 2 root root 4.0K Oct 8 18:14 httpd
    drwxr-xr-x 2 root root 4.0K Oct 8 19:08 php-fpm
    -rw-rw---- 1 mysql root 2.3K Oct 9 12:38 mysqld.log
    -rw------- 1 root root 9.2K Oct 26 10:48 yum.log
    -rw------- 1 root utmp 94K Nov 7 22:59 btmp
    drwxr-xr-x 2 root root 4.0K Nov 8 00:00 sa
    -rw------- 1 root root 269K Nov 8 21:39 messages
    -rw------- 1 root root 110K Nov 8 23:08 secure
    -rw-rw-r-- 1 root utmp 43K Nov 8 23:08 wtmp
    -rw-r--r-- 1 root root 144K Nov 8 23:08 lastlog
    -rw------- 1 root root 69K Nov 8 23:08 lfd.log
    -rw------- 1 root root 332K Nov 8 23:08 maillog
    -rw------- 1 root 500 1.6M Nov 8 23:10 cron
    
    For PHP-FPM error log:
    Code:
    tail -10 /var/log/php-fpm/www-error.log
    
    and/or
    Code:
    /var/log/php-fpm/www-php.error.log
    
    For MySQL / MariaDB error log:
    Code:
    tail -10 /var/log/mysqld.log
    
    For CSF firewall LFD log:
    Code:
    tail -10 /var/log/lfd.log
    
    For Mail log:
    Code:
    tail -10 /var/log/maillog
    
    For Cron job logs:
    Code:
    tail -10 /var/log/cron
    

    How to edit php.ini and php-fpm configuration files ?



    Centmin Mod install created command short cuts outlined here to allow you to quickly edit your /usr/local/lib/php.ini file and your /usr/local/etc/php-fpm.conf file. Full list of command shortcuts below:
    • Edit php.ini = phpedit ( /usr/local/lib/php.ini )
    • Edit my.cnf = mycnf ( /etc/my.cnf )
    • Edit php-fpm.conf = fpmconf ( /usr/local/etc/php-fpm.conf )
    • Edit nginx.conf = nginxconf ( /usr/local/nginx/conf/nginx.conf )
    • Edit (nginx) virtual.conf = vhostconf - only edits /usr/local/nginx/conf/conf.d/virtual.conf not the additional vhost domain.com.conf files added later
    • Edit (nginx) php.conf = phpinc ( /usr/local/nginx/conf/php.conf )
    • Edit (nginx) drop.conf = dropinc ( /usr/local/nginx/conf/drop.conf )
    • Edit (nginx) staticfiles.conf = statfilesinc ( /usr/local/nginx/conf/staticfiles.conf )
    • nginx stop/start/restart = ngxstop/ngxstart/ngxrestart
    • php-fpm stop/start/restart = fpmstop/fpmstart/fpmrestart
    • mysql stop/start/restart = mysqlstop/mysqlstart/mysqlrestart
    • nginx + php-fpm stop/start/restart = npstop/npstart/nprestart
    • memcached stop/start/restart =memcachedstop/memcachedstart/memcachedrestart
    • csf stop/start/restart = csfstop/csfstart/csfrestart

    Troubleshooting Tools



    However, there's many linux tools and scripts that can help you figure out what was causing the load issues and when.

    Tools and commands you will want to read up on and learn for basic system admin tasks and troubleshooting.
    Notes:
    However, Centmin Mod users are free to help each other out and ask questions or give answers on this community forum. My hopes are that this community forum evolves so that more veteran long time Centmin Mod users help new Centmin Mod users out :)
     
  5. RoldanLT

    RoldanLT Well-Known Member

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    Use this instead:
    Code:
    pm = dynamic
    pm.max_children = 96
    pm.start_servers = 24
    pm.min_spare_servers = 12
    pm.max_spare_servers = 48
    pm.max_requests = 1000
     
  6. negative

    negative Member

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    I use these config and follow the errors or what happen.

    What is the ideal settings depend of my server specifications you think @eva2000?
    RoldanLT's advices is perfectly ?
     
  7. RoldanLT

    RoldanLT Well-Known Member

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    Since that is slow CPU, I will lower it to this one:
    Code:
    pm = dynamic
    pm.max_children = 72
    pm.start_servers = 16
    pm.min_spare_servers = 8
    pm.max_spare_servers = 32
    pm.max_requests = 1000
     
  8. RoldanLT

    RoldanLT Well-Known Member

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    My recommendation for PHP-FPM config is not perfect, But based on experience, that's what I think fit with your Server Specs.
     
  9. negative

    negative Member

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    But i don't have any Cpu Load or high cpu usage problem i think. So, i m trying to get max. performance from my server without any problem. Lower settings gives me "WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 8 children, there are 0 idle, and 31 total children" errors.
     
  10. RoldanLT

    RoldanLT Well-Known Member

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    How busy is your site by the way?
     
  11. negative

    negative Member

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    Just one domain online users realtime in google analytics about is 400-600 if that is for understanding the busy.
     
  12. RoldanLT

    RoldanLT Well-Known Member

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    Wp site or Forum?
    Still not that busy.
    But if that's a forum and using VB4, then :D VB4 is really resource hog.
     
  13. negative

    negative Member

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    Only xenforo Forum and a news portal which have custom php script.