The Problem
-----------
We have been getting a "undefined class/module" error on 2 of our 6
app
servers in one testbed.
Same sourcecode, same installs (systemimager and an isconf style
configuration management harness), same binaries.
Identical everything. Pound + mongrel + memcached + postgres (pgcluster).
The odd bit here is that our "dev" and "prod" pairs had one
node
reporting the error, but the other node did not.
The "qa" pair worked just fine with both app servers, without
incident.
Jason Hall reported the same thing on IRC, and we compared notes.
Basically, the problem looks identical to this unanswered RubyForge error:
http://rubyforge.org/tracker/index.php?func=detail&aid=3419&group_id=1266&atid=4982
Here is a snippet from the logs where I was seeing the problem:
/usr/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/lib/mongrel/command.rb:199:in
`run''
/usr/lib/ruby/gems/1.8/gems/mongrel-0.3.13.3/bin/mongrel_rails:235
/usr/bin/mongrel_rails:18
undefined class/module Project
/usr/lib/ruby/gems/1.8/gems/memcache-client-1.0.3/lib/memcache.rb:128:in
`get''
/usr/lib/ruby/1.8/thread.rb:135:in `synchronize''
/usr/lib/ruby/gems/1.8/gems/memcache-client-1.0.3/lib/memcache.rb:98:in
`get''
All of them identical. An error restoring an object from a memcached
session.
I caught Zed online and asked about it, he suggested removing any
"complex datatypes from the session".
I was going this direction when Jason Hall found a "solution":
The Solution
-----------
Jason Hall found a workaround: merely add a "model" line to the
app/controller/application.rb, and those
model :user, :group, :project
From what I''ve been told, "model" is deprecated in Edge
Rails, so this
isn''t a permanent solution.
But this does make for an interim workaround.
I guess my question is: why would a class be undefined? Is this some
kind of a loadpath issue?
- Ian C. Blenke <ian at blenke.com> http://ian.blenke.com/
