Best way to combine fragment and object caching for memcached and Rails

Question

Lets say you have a fragment of the page which displays the most recent posts, and you expire it in 30 minutes. I\'m using Rails here.

<% cache(\"recent_posts         


        

Answer 1

Lars makes a really good point about there being a slight chance of failure using:

unless fragment_exist?("recent_posts")

because there is a gap between when you check the cache and when you use the cache.

The plugin that jason mentions (Interlock) handles this very gracefully by assuming that if you are checking for existence of the fragment, then you will probably also use the fragment and thus caches the content locally. I use Interlock for these very reasons.