-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/33158/
-----------------------------------------------------------
Review request for Ambari, Nate Cole and Tom Beerbower.
Bugs: AMBARI-10456
https://issues.apache.org/jira/browse/AMBARI-10456
Repository: ambari
Description
-------
When mapping hosts concurrently with reading information from a cluster, there
was a deadlock between the building the cluster health report and mapping the
new hosts.
A few changes to note here:
- ClustersImpl uses concurrent maps; there's really no need to keep the
internal lock. I removed it in several places where the cluster is guaranteed
to be available (such as when using the ID to retrieve the cluster). The
concurrent maps guard against concurrent modifications.
- The Ambari Event Publish was actually synchronous. This not only caused
bottlenecks, but also contributed to a secondary deadlock detected while fixing
the original issue. It was changed into a single-threaded asynchronous bus.
Consumers of this bus should never rely on it to perform its actions in order
to perform their own logic, so changing the behavior seemed correct
Diffs
-----
ambari-server/src/main/java/org/apache/ambari/server/events/publishers/AmbariEventPublisher.java
96e66a62
ambari-server/src/main/java/org/apache/ambari/server/state/cluster/ClustersImpl.java
9cf1f5a
ambari-server/src/main/java/org/apache/ambari/server/state/services/AmbariServerAlertService.java
89f9656
ambari-server/src/test/java/org/apache/ambari/server/events/EventsTest.java
09c335a
ambari-server/src/test/java/org/apache/ambari/server/orm/dao/AlertsDAOTest.java
9c8ea7d
ambari-server/src/test/java/org/apache/ambari/server/state/alerts/AlertEventPublisherTest.java
19b5d46
ambari-server/src/test/java/org/apache/ambari/server/state/alerts/InitialAlertEventTest.java
4e55c49
ambari-server/src/test/java/org/apache/ambari/server/state/cluster/ClusterDeadlockTest.java
766105d
ambari-server/src/test/java/org/apache/ambari/server/state/cluster/ClustersDeadlockTest.java
839b25f
ambari-server/src/test/java/org/apache/ambari/server/utils/EventBusSynchronizer.java
PRE-CREATION
Diff: https://reviews.apache.org/r/33158/diff/
Testing
-------
New tests written to cover the deadlocks; existing tests updated for the async
event bus.
Thanks,
Jonathan Hurley
