Connection fix for resque worker

Created by: jcredding

@kellyredding @bearfact @matmcph This should fix gitlab's resque worker failing with the 'mysql server has gone away'.

config/initializers/connection_fix.rb

+# from http://gist.github.com/238999
+#
+# If your workers are inactive for a long period of time, they'll lose
+# their MySQL connection.
+#
+# This hack ensures we re-connect whenever a connection is
+# lost. Because, really. why not?
+#
+# Stick this in RAILS_ROOT/config/initializers/connection_fix.rb (or somewhere similar)
+#
+# From:
+#   http://coderrr.wordpress.com/2009/01/08/activerecord-threading-issues-and-resolutions/
+
 if defined?(ActiveRecord::ConnectionAdapters::Mysql2Adapter)
+
   module ActiveRecord::ConnectionAdapters
+
     class Mysql2Adapter
       alias_method :execute_without_retry, :execute
       def execute(*args)
         execute_without_retry(*args)
-      rescue Mysql2::Error => e
+      rescue ActiveRecord::StatementInvalid => e
         if e.message =~ /server has gone away/i
           warn "Server timed out, retrying"
           reconnect!
@@ -15,5 +30,7 @@ if defined?(ActiveRecord::ConnectionAdapters::Mysql2Adapter)
         end
       end
     end
+
   end
-end
\ No newline at end of file
+
+end