[HIVE-12790] Metastore connection leaks in HiveServer2

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.0
• Fix Version/s: 2.0.0
• Component/s: HiveServer2
• Assignee: Naveen Gangam
• Reporter: Naveen Gangam
• Created: 06/Jan/16 17:46
• Updated: 11/May/17 23:03
• Resolved: 05/Feb/16 14:10

Description

HiveServer2 keeps opening new connections to HMS each time it launches a task. These connections do not appear to be closed when the task completes thus causing a HMS connection leak. "lsof" for the HS2 process shows connections to port 9083.

2015-12-03 04:20:56,352 INFO  [HiveServer2-Background-Pool: Thread-424756()]: ql.Driver (SessionState.java:printInfo(558)) - Launching Job 11 out of 41
2015-12-03 04:20:56,354 INFO  [Thread-405728()]: hive.metastore (HiveMetaStoreClient.java:open(311)) - Trying to connect to metastore with URI thrift://<anonymizedURL>:9083
2015-12-03 04:20:56,360 INFO  [Thread-405728()]: hive.metastore (HiveMetaStoreClient.java:open(351)) - Opened a connection to metastore, current connections: 14824
2015-12-03 04:20:56,360 INFO  [Thread-405728()]: hive.metastore (HiveMetaStoreClient.java:open(400)) - Connected to metastore.
....
2015-12-03 04:21:06,355 INFO  [HiveServer2-Background-Pool: Thread-424756()]: ql.Driver (SessionState.java:printInfo(558)) - Launching Job 12 out of 41
2015-12-03 04:21:06,357 INFO  [Thread-405756()]: hive.metastore (HiveMetaStoreClient.java:open(311)) - Trying to connect to metastore with URI thrift://<anonymizedURL>:9083
2015-12-03 04:21:06,362 INFO  [Thread-405756()]: hive.metastore (HiveMetaStoreClient.java:open(351)) - Opened a connection to metastore, current connections: 14825
2015-12-03 04:21:06,362 INFO  [Thread-405756()]: hive.metastore (HiveMetaStoreClient.java:open(400)) - Connected to metastore.
...
2015-12-03 04:21:08,357 INFO  [HiveServer2-Background-Pool: Thread-424756()]: ql.Driver (SessionState.java:printInfo(558)) - Launching Job 13 out of 41
2015-12-03 04:21:08,360 INFO  [Thread-405782()]: hive.metastore (HiveMetaStoreClient.java:open(311)) - Trying to connect to metastore with URI thrift://<anonymizedURL>:9083
2015-12-03 04:21:08,364 INFO  [Thread-405782()]: hive.metastore (HiveMetaStoreClient.java:open(351)) - Opened a connection to metastore, current connections: 14826
2015-12-03 04:21:08,365 INFO  [Thread-405782()]: hive.metastore (HiveMetaStoreClient.java:open(400)) - Connected to metastore.
... 

The TaskRunner thread starts a new SessionState each time, which creates a new connection to the HMS (via Hive.get(conf).getMSC()) that is never closed.

Even SessionState.close(), currently not being called by the TaskRunner thread, does not close this connection.

Attaching a anonymized log snippet where the number of HMS connections reaches north of 25000+ connections.

Issue Links

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