Ubuntu php5-fpm throws unknown instance on reload

Question

I am having some problems with ubuntu and php5-fpm on my VPS. Php works fine, however it throws terminal error when I am trying to reload / restart / stop it. Basically, I cannot stop php because it does not recognize the instance

It says "reload: Unknown instance:" If I try "service php5-fpm restart" it sais unknown instance and gives this in logs

[15-Nov-2013 11:56:40] ERROR: An another FPM instance seems to already listen on /var/run/php5-fpm.sock [15-Nov-2013 11:56:40] ERROR: FPM initialization failed [15-Nov-2013 11:56:40] NOTICE: configuration file /etc/php5/fpm/php-fpm.conf test is successful 

I have php listening on /var/run/php5-fpm.sock ; I use nginx for webserver and it is correctly configured with

fastcgi_pass unix:/var/run/php5-fpm.sock; 

(or so I know) Also need to mention that this happened after a reboot.

Site is working well, however I don't think this is a good sign. Any thoughts ? Thank you.

EDIT : I did as suggested in below post. It seems that if i kill the process, and then use start/stop it works fine. However, after I use reload command, it stops recongizing the instance.

root@developer2:/# service php5-fpm stop stop: Unknown instance: root@developer2:/# ps -ef UID        PID  PPID  C STIME TTY          TIME CMD root         1     0  0 Nov14 ?        00:00:00 init root      1101     1  0 Nov14 ?        00:00:00 /sbin/udevd --daemon root      1168     1  0 Nov14 ?        00:00:00 /usr/sbin/sshd -D root      1227     1  0 Nov14 ?        00:00:00 /usr/sbin/xinetd -dontfork -pidfile /var/run/xinetd.pid -stayalive -inetd_compa root      1229     1  0 Nov14 ?        00:00:00 cron mysql     1249     1  0 Nov14 ?        00:00:18 /usr/sbin/mysqld syslog    1283     1  0 Nov14 ?        00:00:00 /sbin/syslogd -u syslog memcache  1293     1  0 Nov14 ?        00:00:07 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1 root      1426     1  0 Nov14 ?        00:00:00 /usr/lib/postfix/master postfix   1440  1426  0 Nov14 ?        00:00:00 qmgr -l -t fifo -u root      1468     1  0 Nov14 ?        00:00:00 /usr/sbin/varnishd -P /var/run/varnishd.pid -a :80 -T localhost:6082 -f /etc/va nobody    1469  1468  0 Nov14 ?        00:01:14 /usr/sbin/varnishd -P /var/run/varnishd.pid -a :80 -T localhost:6082 -f /etc/va root      1593     1  0 Nov14 ?        00:00:14 /usr/bin/python /usr/bin/fail2ban-server -b -s /var/run/fail2ban/fail2ban.sock root      1595     1  0 Nov14 ?        00:00:00 /usr/lib/gamin/gam_server www-data  3535     1  0 Nov14 ?        00:00:30 php-fpm: pool www postfix  10016  1426  0 11:18 ?        00:00:00 pickup -l -t fifo -u -c root     10064  1168  0 11:37 ?        00:00:00 sshd: root@pts/0 root     10080 10064  0 11:37 pts/0    00:00:00 -bash root     10143  1168  0 11:47 ?        00:00:00 sshd: root@notty root     10159 10143  0 11:47 ?        00:00:00 /usr/lib/openssh/sftp-server root     11330     1  0 12:03 ?        00:00:00 nginx: master process /usr/sbin/nginx www-data 11331 11330  0 12:03 ?        00:00:00 nginx: worker process www-data 11332 11330  0 12:03 ?        00:00:00 nginx: worker process www-data 11333 11330  0 12:03 ?        00:00:00 nginx: worker process www-data 11334 11330  0 12:03 ?        00:00:00 nginx: worker process root     11465  1168  0 12:14 ?        00:00:00 sshd: root@notty root     11481 11465  0 12:14 ?        00:00:00 /usr/lib/openssh/sftp-server root     11519 10080  0 12:23 pts/0    00:00:00 ps -ef root@developer2:/# kill 3535 root@developer2:/# service php5-fpm start php5-fpm start/running, process 11529 root@developer2:/# service php5-fpm stop php5-fpm stop/waiting root@developer2:/# service php5-fpm start php5-fpm start/running, process 11544 root@developer2:/# service php5-fpm stop php5-fpm stop/waiting root@developer2:/# service php5-fpm start php5-fpm start/running, process 11559 root@developer2:/# service php5-fpm reload root@developer2:/# service php5-fpm reload reload: Unknown instance: 

Edit 2 : my php5 seems to create 3 processes

root     11813     1  1 12:34 ?        00:00:00 php-fpm: master process (/etc/php5/fpm/php-fpm.conf) www-data 11815 11813  0 12:34 ?        00:00:00 php-fpm: pool www www-data 11816 11813  0 12:34 ?        00:00:00 php-fpm: pool www 

When I use reload function the master process dissapears and I have to manually kill the other 2 processes in order to be able to correctly start it again.

Answer 1

This is a Ubuntu bug. In /etc/init/php5-fpm.conf, there is a commented-out line reload signal USR2, which causes the reload function to terminate the php5-fpm master process by sending SIGHUP. Any further reloads, restarts or stops will fail, because the master process has been terminated.

I fixed this in Ubuntu 14.04 by creating a file /etc/init/php5-fpm.override with the single line reload signal USR2 in it. Credits to Jurian Sluiman's comment in this answer.

Here is the primary bug report, proposed workarounds, and confirmation of workaround.

$ ps aux | grep php USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND root      1966  0.0  0.9 473276 37040 ?        Ss   10:03   0:00 php-fpm: master process (/etc/php5/fpm/php-fpm.conf)                     www-data  2009  0.0  1.5 478280 62500 ?        S    10:03   0:01 php-fpm: pool www                                                        www-data  2011  0.0  1.3 476504 55220 ?        S    10:03   0:00 php-fpm: pool www                                                        www-data  2012  0.0  1.6 481592 65840 ?        S    10:03   0:00 php-fpm: pool www  $ sudo service php5-fpm status php5-fpm start/running, process 1966  $ sudo service php5-fpm stop php5-fpm stop/waiting  $ sudo service php5-fpm status php5-fpm stop/waiting  $ sudo service php5-fpm start php5-fpm start/running, process 2651  $ sudo service php5-fpm status php5-fpm start/running, process 2651  $ ps aux | grep php USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND root      2651  0.2  0.9 473276 36996 ?        Ss   10:35   0:00 php-fpm: master process (/etc/php5/fpm/php-fpm.conf)                     www-data  2654  0.0  0.1 473276  7104 ?        S    10:35   0:00 php-fpm: pool www                                                        www-data  2655  0.0  0.1 473276  7104 ?        S    10:35   0:00 php-fpm: pool www                                                        www-data  2656  0.0  0.1 473276  7104 ?        S    10:35   0:00 php-fpm: pool www