resque:failures:sort rake task

This Rake task sorts the "failed" queue into separate failed queues
named after the original job queues, e.g. "myqueue" has a
"myqueue_failed" queue for its failures.

This can be used to migrate to the Resque::Failure::RedisMultiQueue
backend.

Author: tarcieri

lib/resque/tasks.rb

@@ -60,4 +60,19 @@
       Rails::Initializer.run :load_application_classes
     end
   end
+
+  namespace :failures do
+    desc "Sort the 'failed' queue for the redis_multi_queue failure backend"
+    task :sort do
+      require 'resque'
+      require 'resque/failure/redis'
+
+      warn "Sorting #{Resque::Failure.count} failures..."
+      Resque::Failure.each(0, Resque::Failure.count) do |_, failure|
+        data = Resque.encode(failure)
+        Resque.redis.rpush(Resque::Failure.failure_queue_name(failure['queue']), data)
+      end
+      warn "done!"
+    end
+  end
 end