PHP5-FPM crashing: "server reached pm.max_children setting" (Ubuntu 14 - LEMP)

February 2, 2015 15.3k views

My WordPress droplet, 512gb/Ubuntu14/Swap/LEMP/never gave a problem. From today PHP5-FPM writes this message in /var/log/upstart/php5-fpm.log:

WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

So after reading, I've been increasing this size to 30 in /etc/php5/fpm/pool.d/www.conf but still writes the error, now:

server reached pm.max_children setting (30)

What's the reason this is happening now? It hasn't been a high traffic lately, and $free shows 200mb free memory.

  • We will need to see your pool config to get more insight. None of this information points to a clear problem without the full details of the pool (what mode, how many starting children, etc)

  • Sure, details of /etc/php5/fpm/pool.d/www.conf:

    pm = dynamic
    pm.max_children = 30 (original: 5)
    pm.start_servers = 3 (original: 1)
    pm.min_spare_servers = 2 (original: 1)
    pm.max_spare_servers = 4 (original: 3)
    pm.max_requests = 500 (originally commented)
5 Answers

Any news here? One of my servers is having the exact same problem and I can't figure out why.

having same problem, did anyone figure it out?

Having the same problem. I also increase the pm.max_children but it doesn't fixed the problem.

Someone could do a good job for the humanity and answer this! :)

Is this even a problem? What is this warning?

Have another answer? Share your knowledge.