Using supervisord for Nginx+FastCGI+PHP
Posted on June 23rd, 2010 by Sacha Chua
I was having problems with spawn-fcgi-standalone occasionally resulting in dead PHP processes, which caused 502 Bad Gateway errors on my site. Crontabbing an /etc/init.d/init-fastcgi start didn’t help much, so I looked for other ways to do it. Supervisord looked promising.
Here’s how to get Supervisord:
apt-get install python-setuptools easy_install supervisor
Here’s what to add to /etc/supervisord.conf:
[fcgi-program:php5-cgi] socket=tcp://127.0.0.1:9000 command=/usr/bin/php5-cgi numprocs=5 priority=999 process_name=%(program_name)s_%(process_num)02d user=www-data autorestart=true autostart=true startsecs=1 startretries=3 stopsignal=QUIT stopwaitsecs=10 redirect_stderr=true stdout_logfile=/var/log/php5-cgi.log stdout_logfile_maxbytes=10MB
So far, so good. When I kill the php process, supervisord starts it back up. Progress!
supervisord doesn’t come with an init.d script, but you can get one for Ubuntu.
Short URL: http://sachachua.com/blog/p/7227
But…what is the root of the problem? Why is PHP dying? Can you sleep at night without knowing this?
I came across some webpages that suggested php-fcgi wasn’t the most reliable way to do it (long pages would die, etc.), and that fpm or supervisord might be better. This way, I can keep the extraneous bad gateway errors from my error logs, and focus on what’s causing the occasional process to die.
Have you heard of Monit? I use for supervising both nginx and php-cgi. It’s written in C and not in Python. http://mmonit.com
I’ve published by monit configuration for supervising MariaDB (MySQL), nginx, and php-cgi, among other things on github: http://github.com/perusio/monit-miscellaneous just in case you’re interested in checking out monit.
Thanks for sharing!
Supervisord has been great to work with. However, sometimes it seems to not want to log to the specified stdout_logfile . Even tho there is absolutely std out.
Have you ever had issues with supervisord logging to stdout_logfile ?
Thanks. very helpful.. Finally configured it for my blog with auto start. No worries about crashing php5-cgi process.
@warren: Yeah! i’m seeing the same thing. Ever figure it out?
Yea, supervisord only logs in bursts when there is enough data for the particular process. In my case it was only writing when there was ~1K worth of data (and it was a timed job, so it appeared to be related to time – but that was not the case).
I have also seen some strange behavior with the log rotation. For example, if you are logging to test.log, sometimes you will find it is logging to test.log.5
A ls -lart helps with that :)
All things considered, supervisord has been doing a great job. We have been using it in production for a couple months.