[SENTRY-1929] When full HMS snapshot is created all higher notifications should be purged

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Component/s: Sentry
• Assignee: Alex Kolbasov
• Reporter: Alex Kolbasov
• Created: 07/Sep/17 00:27
• Updated: 08/Sep/17 00:15
• Resolved: 08/Sep/17 00:15

Description

The problem was discovered by vamsee when he cleared up HMS notifications manually.

Sentry goes in a loop:

2017-09-06 16:56:59,923 INFO hive.metastore: Closed a connection to metastore, current connections: 10
2017-09-06 16:56:59,932 INFO hive.metastore: Closed a connection to metastore, current connections: 9
2017-09-06 16:56:59,938 INFO hive.metastore: Closed a connection to metastore, current connections: 8
2017-09-06 16:56:59,946 INFO hive.metastore: Closed a connection to metastore, current connections: 7
2017-09-06 16:56:59,949 INFO hive.metastore: Closed a connection to metastore, current connections: 6
2017-09-06 16:56:59,949 INFO hive.metastore: Closed a connection to metastore, current connections: 5
2017-09-06 16:56:59,952 INFO hive.metastore: Closed a connection to metastore, current connections: 4
2017-09-06 16:56:59,952 INFO hive.metastore: Closed a connection to metastore, current connections: 3
2017-09-06 16:56:59,955 INFO hive.metastore: Closed a connection to metastore, current connections: 2
2017-09-06 16:56:59,955 INFO org.apache.sentry.service.thrift.SentryHMSClient: Obtained full HMS snapshot
2017-09-06 16:56:59,959 INFO org.apache.sentry.service.thrift.SentryHMSClient: NotificationID, Before Snapshot: 263, After Snapshot 263
2017-09-06 16:56:59,959 INFO org.apache.sentry.service.thrift.SentryHMSClient: Successfully fetched hive full snapshot, Current NotificationID: CurrentNotificationEventId(eventId:263).
2017-09-06 16:56:59,963 ERROR org.apache.sentry.service.thrift.CounterWait: new counter value 263 is smaller then the previous one 9025
2017-09-06 16:56:59,963 INFO org.apache.sentry.service.thrift.HMSFollower: Sentry HMS support is ready
2017-09-06 16:56:59,973 INFO org.apache.sentry.service.thrift.HMSFollower: The latest notification ID on HMS is less than the latest notification ID processed by Sentry. Need to request a full HMS snapshot.
2017-09-06 16:56:59,975 INFO org.apache.sentry.service.thrift.SentryHMSClient: Request full HMS snapshot
2017-09-06 16:56:59,975 INFO hive.metastore: Trying to connect to metastore with URI thrift://foo.com:9083
2017-09-06 16:56:59,981 INFO hive.metastore: Opened a connection to metastore, current connections: 3
2017-09-06 16:56:59,981 INFO hive.metastore: Connected to metastore.
2017-09-06 16:56:59,986 INFO hive.metastore: Closed a connection to metastore, current connections: 2
2017-09-06 16:56:59,986 INFO hive.metastore: Trying to connect to metastore with URI thrift://foo.com:9083
2017-09-06 16:56:59,986 INFO hive.metastore: Trying to connect to metastore with URI thrift://foo.com:9083
2017-09-06 16:56:59,987 INFO hive.metastore: Trying to connect to metastore with URI thrift://foo.com:9083

The problem is that when we detect some weirdness and read the new full snapshot there may be larger NotificationID in the DB which will cause us to get a new snapshot again.

As part of saving the full snapshot to DB we should remove all notifications with ID higher then the one in the snapshot.

Issue Links

• links to: Code review