Bug 785968

+++ This bug was initially created as a clone of Bug #767328 +++

1) Create a drift template.
2) Go to resource #1 and create a drift definition from that template
3) Go to resource #2 and create a drift definition from that template
   (I'm not sure, but I think if you just create two definitions from the same template, even on the same resource, the same bug shows up, but I used two resources)
4) Edit the drift template (change the enabled flag, or the interval) and save

boom.

--- Additional comment from mazz on 2011-12-13 14:54:35 EST ---

git commit 9b42a3a83b51bdce587b6841774e373b25343e5a doesn't fix this bug, but it fixes another bug that shows up when basedir is null (which is the real problem - basedir should not be null). See the diff of that commit for details.

--- Additional comment from jsanda on 2011-12-13 17:27:21 EST ---

Template updates are propagated to attached definitions. This means that DriftManagerBean.updateDriftDefinition is invoked for each attached definition. Note that this all occurs within the same transaction. updateDriftDefinition sends a request to the agent to add/update the definition. To avoid hibernate proxy issues on the agent, we flush and clear the persistence context before calling the agent. When updateDriftDefinition is called for the second definition, the proxy for DriftDefinition.configuration has been cleared and we wind up with the following exception,

Caused by: java.lang.NullPointerException
        at org.rhq.enterprise.server.drift.DriftManagerBean.validateDriftDefinition(DriftManagerBean.java:804)
        at org.rhq.enterprise.server.drift.DriftManagerBean.updateDriftDefinition(DriftManagerBean.java:720)

The short term, temporary solution is to reload each definition before we call updateDriftDefinition.

master commit hash: ee66d10c7c3dee5a9c9bd102d9ea2db347e0e769

I was talking with mazz and jshaughn about a longer term solution that involves sending requests to agents out of band using quartz. The solution ought to be generic as it would have applicability in other places outside of drift code.

--- Additional comment from skondkar on 2011-12-14 06:58:45 EST ---

Verified on master build#833 (Version: 4.3.0-SNAPSHOT Build Number: ee66d10)

Imported two EAP5.x servers and created a drift template on JBossAS5 server. Created drift definitions from that template on both the EAP servers.
   
Verified that editing and saving the drift template does not throw any exception and the attached drift definitions are updated successfully.

Also verified by creating two definitions from the same template on the same resource and updating the template.

--- Additional comment from ccrouch on 2012-01-30 22:13:37 EST ---

Setting the Target Release version correctly to match where the issue was tested.