Rails cache expire

Question

I have a rails application, in that I am using simple rails cache. My testing is as follows:

Rails.cache.write(\'temp\',Date.today,:expires_in => 60.seconds)
         


        

Answer 1

After some search, I have found one possible reason why the cache is not cleaned after 60 seconds.

1. You call Rails.cache.write which is documented here.
2. It calls write_entry(namespaced_key(name, options), entry, options), where your option :expires_in is one part of the options argument.

3. The implementation of write_entry has the following condition:

   if expires_in > 0 && !options[:raw]
       # Set the memcache expire a few minutes in the future to support race condition ttls on read
       expires_in += 5.minutes
   end
   

So there are 5 minutes added to your 60 seconds. 2 possible solutions:

• Just live with it :-)
• Try to include the option :raw => true, perhaps this will skip the condition, so that your expiry works as suspected.