Mike Perham

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Using memcache-client 1.6.x in Rails < 2.3

March 3rd, 2009 · 12 Comments

Jemery Kemper recently upgraded Rails 2.3’s vendored copy of memcache-client to the 1.6.4 release. But what do you do if you are running Rails 2.1/2.2 and want to take advantage of the massive speedup in 1.6.x? You write some really ugly code that performs brain surgery on the Ruby environment to override ActiveSupport. Create config/initializers/memcache-client-upgrade.rb with this code:

require 'rubygems'
 
# Brain surgery to use our own version of memcache-client without
# having to modify activesupport directly.
# Unload any previous instance of the class
if Object.const_defined? :MemCache
  Object.instance_eval { remove_const :MemCache }
end
# Pull in the exact version we want
gem 'memcache-client', '1.6.5'
# Ensure that the memcache-client path is at the front of the loadpath
$LOAD_PATH.each do |path|
  if path =~ /memcache-client/
    $LOAD_PATH.delete(path)
    $LOAD_PATH.unshift(path)
  end
end
# If Ruby thinks it's already loaded memcache.rb, force
# a reload otherwise just require.
if $".find { |file| file =~ /\Amemcache.rb\Z/ }
  load 'memcache.rb'
else
  require 'memcache'
end

If someone knows of a cleaner way to do this, please let me know.

Tags: Rails

12 responses so far ↓

  • 1 JGeiger // Mar 3, 2009 at 10:03 am

    Thanks.

  • 2 fazibear // Mar 13, 2009 at 6:09 am

    It’s cleaner if you move it to config/initializers/memcache_fix.rb

  • 3 mperham // Mar 13, 2009 at 6:26 am

    Thanks, good idea. I forgot that load order doesn’t matter since we’re unloading everything. I’ve updated the post.

  • 4 fazibear // Mar 13, 2009 at 6:44 am

    Wait! I think it does matter. It won’t work from initializers scripts! But why ?

  • 5 Jerrett // May 13, 2009 at 7:32 pm

    Yikes, that sucks. Hopefully they will add the 1.7.x to rails so we don’t have to do this

  • 6 eventually consistent » Blog Archive » Rails MemCacheStore Fu // Jun 10, 2009 at 10:46 pm

    [...] Mike’s instructions to performs brain surgery on the Ruby environment to override ActiveSupport [...]

  • 7 Colin Surprenant // Jun 10, 2009 at 11:23 pm

    Thanks, that worked for me with memcache-client 1.7.4 and Rails 2.2.2.

    I have also written a quick tutorial on how to do this and also control the MemCacheStore options using a memcached.yml config file (from cache_fu/acts_as_cached) on http://eventuallyconsistent.com/blog/2009/06/rails-memcachestore-fu/

    Colin.

  • 8 chris // Jul 1, 2009 at 6:04 pm

    Does this work if memcache-client 1.7.4 is vendored?

    I am getting this error:
    Could not find RubyGem memcache-client (= 1.7.4)

    On this line:
    # Pull in the exact version we want
    gem ‘memcache-client’, ‘1.7.4′

    Any tips?

  • 9 mperham // Jul 1, 2009 at 6:45 pm

    I guess not. :-)

  • 10 FoundChris » Blog Archive » Using the latest memcache-client in Rails // Jul 2, 2009 at 6:12 pm

    [...] Perham, the memcache-client maintainer, documented how to do this (”Using memcache-client 1.6.x in Rails < 2.3″).  His hack works great if the [...]

  • 11 chris // Jul 2, 2009 at 6:13 pm

    Here is how I got 1.7.4 going without relying on an external gem:

    http://www.foundchris.com/2009/07/02/using-the-latest-memcache-client-in-rails/

    Cheers.

  • 12 Mike Subelsky // Jul 27, 2009 at 3:16 pm

    Here’s how I’m using the vendored gem in Rails 2.2.x:

    http://gist.github.com/156741

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