[SOLR-11216] Race condition in peerSync

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 7.4
• Fix Version/s: 7.5, 8.0
• Assignee: Cao Manh Dat
• Reporter: Cao Manh Dat
• Created: 09/Aug/17 08:15
• Updated: 27/Sep/21 12:50
• Resolved: 20/Jun/18 16:41

Description

When digging into SOLR-10126. I found a case that can make peerSync fail.

• leader and replica receive update from 1 to 4
• replica stop
• replica miss updates 5, 6
• replica start recovery
  1. replica buffer updates 7, 8
  2. replica request versions from leader,
  3. in the same time leader receive update 9, so it will return updates from 1 to 9 (for request versions) when replica get recent versions ( so it will be 1,2,3,4,5,6,7,8,9 )
  4. replica do peersync and request updates 5, 6, 9 from leader
  5. replica apply updates 5, 6, 9. Its index does not have update 7, 8 and maxVersionSpecified for fingerprint is 9, therefore compare fingerprint will fail

Issue Links

• relates to: SOLR-10126 PeerSyncReplicationTest is a flakey test.
• relates to: SOLR-15655 tweak PeerSync(WithLeader) debug logging