Ubuntu 12.04 x64 ~ LEMP+WordPress: PHP keeps crashing

October 28, 2013 5.2k views
Hi folks, I'm running a 512MB RAM droplet with 2 separate single WP installs. Both vhost configs are identical. One of them is very new with just 6 posts so far. The other has been around since Dec '12. I need some help here. For the life of me, I can't figure out why PHP keeps crashing. I had the same problem with PHP5.3 + APC. Now I'm on PHP5.5 with ZendOpcache. I have to keep checking my site every now and then and login via SSH to restart PHP. Doesn't sound right to me. i. repository ppa:ondrej/php5 ii. repository ppa:nginx/stable If someone could take a look at my configs and let me know what's not right, will be greatly appreciated. I'm new to VPS have moved from a cPanel Shared Hosting. I like to seed now and hate to return to shared hosting should things not work out for me. 1. /etc/nginx/nginx.conf: http://pastebin.com/A6GTZkwx 2. /etc/nginx/sites-available/mydomain: http://pastebin.com/GiiCLX0L 3. /etc/php5/fpm/php.ini: http://pastebin.com/AYQSae6v I'm prepared to move the newer WP install to a shared host if required. I am currently not running W3TC or CloudFlare. I reckon I should be sorting out the crashing PHP before all else.
10 Answers
Have you installed swap (MySQL eats up a lot of resources)? If not, check out How To Add Swap on Ubuntu 12.04.
by Etel Sverdlov
Linux swaps allow a system to harness more memory than was originally physically available. Here's how to set up a linux swap file on Ubuntu 12.04
Hi Pablo, not yet but I will look into that. I have up the ZendOpcache memory from 128M default to 256M. It's probably gonna delay the issue at best I think.
If it's performance you're interested in, you may want to check out How To Install Wordpress, Nginx, PHP, and Varnish on Ubuntu 12.04.
by Etel Sverdlov
Varnish is an HTTP accelerator and a useful tool for speeding up a server, especially during a times when there is high traffic to a site. It works by redirecting visitors to static pages whenever possible and only drawing on the server itself if there is a need for an active process. This tutorial covers installing wordpress on a LEMP stack (with nginx instead of apache), and then installing varnish.
@Nicholas: I don't recommend doing that on a 512MB droplet. 256MB of free RAM isn't enough for MySQL -- it'll crash. Try adding swap and/or upgrading your droplet.
@Kamal. Thanks for your input. I actually set ZendOpcache to 192MB and installed Varnish as suggested by Pablo. Seems like PHP is holding and hasn't crashed.

Does Varnish stop WordPress/PHP from caching? If so. does that mean my FastCGI settings are messed up in the first place?

Be great if some could take a look at my configs and let me know if something is out of place. I haven't installed swap yet. Upgrading is a possibility I guess but be silly if PHP still crashes after that...
Varnish acts as a reverse proxy and does not affect php5-fpm's behavior at all. You can upgrade your droplet temporarily and see if that fixes it. Since billing is hourly it will cost you next to nothing :]
@Kamal, yeah I could do that. Erm, noob question. How do I temporarily switch off varnish for the test?
You can just browse to http://yourip:nginxport
Guys, thanks for the help. PHP seems to be holding with Varnish installed. http://wp.me/pc4Vf-2b
Have another answer? Share your knowledge.