Symfony, performance, and High CPU usage

• October 13, 2009
• symfony  
• cpu  
• load  
• performance  
• slow  
• symfony  
• usage  

Server is slowing down, and noticing that your Symfony project is consuming enormous amount of CPU? Try this tweak:

# factories.yml
all:
  routing:
    class: sfPatternRouting
    param:
      cache: null

What it does: This config disables the Symfony Routing Cache, which uses PHP serialize/unserialize functions, and can cause lots of CPU processing.

In my case, a high server load of ~8 went under 1 with this simple tweak (on a dual core). Easy change, but hard to find in the docs.

This was the one most important tweak that reduced my server load, but there are a few others, including:

• A variation of the above tweak, by enabling lazy_routes_deserialize in factories.yml (doc)
• Disable check_lock in settings.yml (doc)
• Disable the Symfony compressor (doc)

Happy tweaking!