php-fpm子进程退出信号11

Question

Our application run on docker container on AWS. Operating system: Ubuntu 14.04.2 LTS Nginx Version: nginx/1.4.6 (Ubuntu) Memcached Version: memcached 1.4.14 PHP Version: PHP 5.5.9-1ubuntu4.11 (cli) (built: Jul 2 2015 15:23:08) System Memory: 7.5 GB

We get blank pages and 404 Error less frequently. While checking the logs found that php-child process is killed and it seems that memory is mostly used by memcache and php-fpm process and very low free memory.

memcache is configured to use 2GB memory.

Here is php www.conf

pm = dynamic
pm.max_children = 30
pm.start_servers = 9
pm.min_spare_servers = 4
pm.max_spare_servers = 14
rlimit_files = 131072 
rlimit_core = unlimited

Error logs

/var/log/nginx/php5-fpm.log 
[29-Jul-2015 14:37:09] WARNING: [pool www] child 259 exited on signal 11 (SIGSEGV - core dumped) after 1339.412219 seconds from start

/var/log/nginx/error.log 

2015/07/29 14:37:09 [error] 141#0: *2810 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: x.x.x.x, server: _, request: "GET /suggestions/business?q=Selectfrom HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "example.com", referrer: "http://example.com/"

/var/log/nginx/php5-fpm.log  
[29-Jul-2015 14:37:09] NOTICE: [pool www] child 375 started


/var/log/nginx/php5-fpm.log:[29-Jul-2015 14:37:56] WARNING: [pool www] child 290 exited on signal 11 (SIGSEGV - core dumped) after 1078.606356 seconds from start

Coredump

Core was generated by php-fpm: pool www.Program terminated with signal SIGSEGV, Segmentation fault.#0  0x00007f41ccaea13a in memcached_io_readline(memcached_server_st*, char*, unsigned long, unsigned long&) () from /usr/lib/x86_64-linux-gnu/libmemcached.so.10

dmesg

[Wed Jul 29 14:26:15 2015] php5-fpm[12193]: segfault at 7f41c9e8e2da ip 00007f41ccaea13a sp 00007ffcc5730ce0 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]
[Wed Jul 29 14:28:26 2015] php5-fpm[12211]: segfault at 7f41c966b2da ip 00007f41ccaea13a sp 00007ffcc5730ce0 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]
[Wed Jul 29 14:29:16 2015] php5-fpm[12371]: segfault at 7f41c9e972da ip 00007f41ccaea13a sp 00007ffcc5730b70 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]
[Wed Jul 29 14:35:36 2015] php5-fpm[12469]: segfault at 7f41c96961e9 ip 00007f41ccaea13a sp 00007ffcc5730ce0 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]
[Wed Jul 29 14:35:43 2015] php5-fpm[12142]: segfault at 7f41c9e6c2bd ip 00007f41ccaea13a sp 00007ffcc5730b70 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]
[Wed Jul 29 14:37:07 2015] php5-fpm[11917]: segfault at 7f41c9dd22bd ip 00007f41ccaea13a sp 00007ffcc5730ce0 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]
[Wed Jul 29 14:37:54 2015] php5-fpm[12083]: segfault at 7f41c9db72bd ip 00007f41ccaea13a sp 00007ffcc5730ce0 error 4 in libmemcached.so.10.0.0[7f41ccad2000+32000]

Please let me know if needs more informations

Thanks in advance

Answer 1

It can happen if php is unable to write session information to file By default it is /var/lib/php/session You can change it by using configuration session_save_path

https://serverfault.com/questions/427596/phpmyadmin-having-problems-on-nginx-and-php-fpm-on-rhel-6/429445