Nginx + php5-fpm graceful restart : reload on Ubuntu 14.04 LTS

nginxphp-fpmubuntu-14.04

I tried to find a way to gracvelly restart my server.

I tried sudo service php5-fpm reload && sudo service nginx reload

But this is not working as reloading php5-fpm on Ubuntu 14.04 is not working properly (The php5-fpm instance is showed as unknown)

After executing the previously command I got

sudo service php5-fpm status
> php5-fpm stop/waiting
sudo service php5-fpm restart
> stop: Unknown instance: 
> php5-fpm start/running, process 26042
sudo service php5-fpm restart
> stop: Unknown instance: 
> php5-fpm start/running, process 26141

The only way I found to restart php5-fpm after that is to run:

sudo killall php5-fpm
sudo service php5-fpm start
> php5-fpm start/running, process 26160

Thank You,

Best Answer

this one was killing me and all my coworkers too :) Here's the solution: Edit the file:

/etc/init/php5-fpm.conf

and uncomment the line containing (it's line 13 on my box):

reload signal USR2

Then kill all the php-fpms:

find their process ids:

ps aux | grep php-fpm

kill them:

sudo kill [proc-id]

And voila your "sudo service php5-fpm restart" is working again

Related Solutions

Nginx – How to Add a Pool to FPM Without Reloading

I don't believe there is any way to add a pool without restarting/reloading (as per this).

I do think that redundancy is the best approach to this, I do believe, that you might accomplish what you want with reload. Since it is a graceful reload it should wait for the processes to finish.

Essentially, pass the SIGUSR2 signal to php-fpm, and it will gracefully reload all workers + reload the fpm conf/binary.

I believe that amounts to

kill -USR2 `cat $php_fpm_PID`

So, you modify the conf - and reload - shouldn't result in noticeable downtime.

Another option is to run one process per user - you can add new users without terminating existing processes, but the resource requirements are significantly higher (and, for 1000+ users aren't likely to be practical).

One more option is to create a temporary php-cgi process for the new user, and delay reloading the server until later (i.e. low load period, or when you have multiple users to add). This would reduce downtime, but still bring up the new user's subdomain immediately.

None of the above are exactly ideal, and the only practical solution to no downtime would be the multiple server approach.

Nginx – Constantly have to reload PHP-FPM

You're using php-fpm, so I suggest to be more aggressive with how long php-fpm's children are allowed to live. You need to find the sweet spot between shortly lived threads/children and stability. The php-fpm defaults are way to generous for any production system, IMHO.

I'd reduce the number for pm.max_requests for your production pools. I think the default is 200. I'd start from 50 and see where that takes you.

Failing/complementary to that, you could also try these global options (AFAIK they are all disabled by default):

emergency_restart_threshold=3
emergency_restart_interval=1m
process_control_timeout=5s

What does this mean? If 3 PHP-FPM child processes exit with SIGSEGV or SIGBUS (i.e. crash) within 1 minute then PHP-FPM is supposed to restart automatically. The child processes wait 5s for a reaction on signals from master.

This should keep your pool of PHP worker threads nice, fresh and clean. The longer a worker is allowed to furnish requests, more unstable it will get. There's also a higher risk of memory leaks.

Here's a nice overview of all the config options I mentioned here, as well as others: http://myjeeva.com/php-fpm-configuration-101.html

Hope these tips help you! Remember to tweak and observe, unfortunately there doesn't seem to be a rule of thumb for all this, there are too many variables that affect PHP's behaviour and stability.

Best Answer

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Nginx – How to Add a Pool to FPM Without Reloading

Nginx – Constantly have to reload PHP-FPM

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