Friday, 24 July 2009

move from ec2onrails

Recently the performance on has been plummeting. And I had no idea why. Often apache was timing out waiting for a mongrel. Very little development has happened recently on FilmAmora, so I was stumped.
So - like a good developer - I took this as a chance to make a drastic move from ec2onrails machines to straight ubuntu, with everything else installed by hand.

It has made a HUGE difference. So much so that I could actually drop a machine from the configuration and still have better response times.

I followed these instructions to get started: rails-nginx-passenger-ubuntu. I also switched to nginx and ruby enterprise edition - just to make following the instructions easier.

So far so good. It took a couple hours and presto a leaner meaner installation. My NewRelic Apdex score went from .5 to .9.

Friday, 17 July 2009

expiring action_cache

I was having a bugger of a time expiring my cache. The problem was the cache_path.
I have index actions that take filters. So, I created a cache_path for my action caching:

caches_action :index, :layout => false, :cache_path => { |c| "#{c.params[:league_id]}/index/#{c.params.values.sort.to_s}" }

Which means that all my caches end up in a nice tree of 'views/[league name]'. But, how to expire a whole part of the cache tree when there could be dozens of nodes as people could be searching on last names too.

What I found was that expire_action was NOT the way to go. expire_fragment lets you pass in a regular expression. Now in my sweeper I have this:

  def expire_cache_for(player)

Which will expire all the cached code for the player's league.