[HDDS-9747] Incorrect sorting order for all unhealthy replicas in RatisOverReplicationHandler

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.4.0
• Component/s: SCM
• Labels: pull-request-available
• Target Version/s: 1.4.0
• Assignee: Stephen O'Donnell
• Reporter: Siddhant Sangwan
• Created: 21/Nov/23 14:21
• Updated: 14/Dec/23 08:33
• Resolved: 30/Nov/23 07:30

Description

    if (allUnhealthy) {
      // prefer deleting replicas with lower sequence IDs
      return replicas.stream()
          .sorted(Comparator.comparingLong(ContainerReplica::getSequenceId)
              .reversed())
          .collect(Collectors.toList());
    }

This should actually be the opposite, allowing lower sequence IDs to be deleted first. Also need to consider what happens when two replicas have the same sequence ID - how are ties broken? Consistent ordering matters in case of SCM failover.

Issue Links

• links to: GitHub Pull Request #5689