[SENTRY-1784] DBUpdateForwarder returns empty update list to HDFS instead of full update

• Type: Sub-task
• Status: Resolved
• Priority: Critical
• Resolution: Duplicate
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Component/s: Sentry
• Assignee: Sergio Peña
• Reporter: Na Li
• Created: 25/May/17 02:20
• Updated: 24/Jul/17 14:51
• Resolved: 06/Jul/17 18:20

Description

When HDFS first asks Sentry for update, the request changeID is 1. If there is no entries in permission change table (current changeID is 0), empty update list is returned to HDFS because the current code behavior is that no update is returned if request changeID is larger than the current chaneID.

Once this problem is fixed (returning full update when request changeID = 1, and current changeID = 0), another issue of the current code is that after a full update is sent to client, and there is no entries in permission change table (current changeID is 0), the next request changeID is still 1,
so full update is returned for the second time. Full update will be sent for each request until permission change table has at least one entry.

The desired behavior is for HDFS to get full update when it sends the first request to Sentry. Once it gets full update, the following requests should get delta updates unless some updates are purged before they are sent to HDFS.

Issue Links

• duplicates: SENTRY-1815 Send new HMS snapshots to HDFS requesting an old generation ID
• is broken by: SENTRY-1613 Add propagating logic for Perm/Path updates in Sentry service
• links to: Review Link for this case