[
https://issues.apache.org/jira/browse/HIVE-13149?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15169902#comment-15169902
]
Chaoyu Tang commented on HIVE-13149:
------------------------------------
It might not be proper to share the HMS connection opened in HS2 main process,
but I think the session one could be shared which can avoid opening connection
in the spawned task thread, is not it? In addition, when these threads finish
the tasks and die, should not they be collected?
> Remove some unnecessary HMS connections from HS2
> -------------------------------------------------
>
> Key: HIVE-13149
> URL: https://issues.apache.org/jira/browse/HIVE-13149
> Project: Hive
> Issue Type: Sub-task
> Components: HiveServer2
> Affects Versions: 2.0.0
> Reporter: Aihua Xu
> Assignee: Aihua Xu
> Attachments: HIVE-13149.1.patch
>
>
> In SessionState class, currently we will always try to get a HMS connection
> in {{start(SessionState startSs, boolean isAsync, LogHelper console)}}
> regardless of if the connection will be used later or not.
> When SessionState is accessed by the tasks in TaskRunner.java, although most
> of the tasks other than some like StatsTask, don't need to access HMS.
> Currently a new HMS connection will be established for each Task thread. If
> HiveServer2 is configured to run in parallel and the query involves many
> tasks, then the connections are created but unused.
> {noformat}
> @Override
> public void run() {
> runner = Thread.currentThread();
> try {
> OperationLog.setCurrentOperationLog(operationLog);
> SessionState.start(ss);
> runSequential();
> {noformat}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
