Limit number of php-cgi processes spawned by nginx

Here’s how to Mine was around here somewhere.

File was here

sudo nano /usr/bin/php-fastcgi

Original file looked something like this.

/usr/bin/spawn-fcgi -a -p 10005 -u www-data -g www-data -f /usr/bin/php-cgi

Added -C argument to enforce a limit.

/usr/bin/spawn-fcgi -C 2 -a -p 10005 -u www-data -g www-data -f /usr/bin/php-cgi

I just got a notice from my VPS host that my box was using too much swap and therefore impacting other users on the machine. As such, my provider did a hard reset on my instance which summarily stopped my web app (I don’t start the app on startup. I should.)

I just upgraded my server a few versions up the Ubuntu chain because of the heartbleed SSL bug so obviously it was something related to the upgrade. I’m not super savvy with figuring out which components changed so I figured if I could just cut back on the memory usage things wouldn’t go to swap. My server is running an app and a couple of old Drupal blogs that don’t get much traffic but I like to keep around for nostalgia. So, I figured I could sacrifice substantial performance on the blogs.

Things I changed to hopefully save memory:
* reduce max_connections to 50 from Not specified.

* reduce memory_limit from 128M to 64M

* add “-C” flag to constrain number of processes to 3. (default was 5)

The php5-cgi change by far had the largest affect because each php5-cgi process was using 25MB per thread (~125MB, or 50% of my 256MB VPS).