Created attachment 994030 [details]
Patch

+++ This bug was initially created as a clone of Bug #1175939 +++

Description of problem:

When subscribing systems to a channel from the channel's Target Systems tab, each system is processed in turn, and each system's errata cache is updated synchronously. For even a relatively small number of systems, the web UI takes several minutes to complete the action, and returns an Internal Server Error because the session timeout has been exceeded. Reproduced internally with 10 systems subscribed to rhn-tools-rhel-x86_64-server-6, which hung for 3.5 minutes before returning an ISE.

Version-Release number of selected component (if applicable):

spacewalk-java-2.0.2-92.el6sat.noarch

How reproducible:

100%

Steps to Reproduce:
1.) See Description above.

Actual results:

Long delay after submitting action, followed by ISE.

Expected results:

No ISE, submitted action completes quickly.

Additional info:

Changing the subscribe_server_to_channel query in ./java/code/src/com/redhat/rhn/common/db/datasource/xml/Channel_queries.xml to regenerate the errata cache asynchronously reduced the time from 3.5 minutes to 20 seconds (with no ISE) for the reproducer mentioned above. Proposed patch attached.