[SENTRY-2106] If Sentry is ahead do not trigger a full snapshot

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: 2.1.0
• Fix Version/s: 2.1.0
• Component/s: Sentry
• Labels: features
• Assignee: Arjun Mishra
• Reporter: Arjun Mishra
• Created: 20/Dec/17 17:44
• Updated: 09/Mar/18 09:25
• Resolved: 09/Mar/18 09:25

Description

After steady state, a full snapshot is triggered by mainly 2 cases

1. Sentry is "ahead"
2. Sentry is behind
   Case 1 has a dependency on NOTIFICATION_SEQUENCE table. This is not reliable as it was observed that sometimes NOTIFICATION_SEQUENCE and NOTIFICATION_LOG are not in sync. As a result of this unnecessary full snapshots can be triggered.

The fix is to remove this dependency

 

PLEASE NOTE THAT THIS SHOULD BE COMMITTED WITH SENTRY-2109

Issue Links

• is required by: SENTRY-2109 Fix the logic of identifying HMS out of Sync and handle gaps and out-of-sequence notifications.
• relates to: HIVE-18526 Backport HIVE-16886 to Hive 2
• relates to: HIVE-16886 HMS log notifications may have duplicated event IDs if multiple HMS are running concurrently
• links to: Review board link