[jira] [Created] (AMBARI-9965) RU - Improve performance for large cluster in StackVersionListener

["Tom Beerbower (JIRA)" <ji...@apache.org>]

Tom Beerbower created AMBARI-9965:
-------------------------------------

             Summary: RU - Improve performance for large cluster in StackVersionListener
                 Key: AMBARI-9965
                 URL: https://issues.apache.org/jira/browse/AMBARI-9965
             Project: Ambari
          Issue Type: Task
            Reporter: Tom Beerbower
            Assignee: Tom Beerbower
             Fix For: 2.0.0


On a large cluster, all of the agents will heartbeat during registration at the same time, so the HearbeatHandler has to be fast. Right now, the logic to handle host versions is done as part of StackVersionListener, which uses the AmbariEventPublisher, and acquires a lock.
*This means that the heatbeats will compete for the same lock in a piece of code that makes a lot of DB calls.*

Use a separate EventBus since we should not listen for host version changes using AmbariEventPublisher

We should also move HearbeatHandler.java (around line 520)
{code}
HostComponentVersionEvent event = new HostComponentVersionEvent(cl, scHost);
ambariEventPublisher.publish(event);
{code}
inside the handleComponentVersionReceived() method.

As an optimization, we should consider only registering the event if "previousVersion" differs from the new value.




--
This message was sent by Atlassian JIRA
(v6.3.4#6332)