[HBASE-16164] Missing close of new compacted segments in few occasions which might leak MSLAB chunks from pool

• Type: Sub-task
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.0.0
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Anoop Sam John
• Reporter: Anoop Sam John
• Created: 01/Jul/16 08:54
• Updated: 24/Jun/22 18:14
• Resolved: 02/Jul/16 06:14

Description

An in memory compaction of N segments in progress. Inn between snapshot() call comes. We will stop the in progress compaction then. This just sets an AtomicBoolean. We check this boolean state in the compaction loop (while loop reading the cells from the segments) and before swapping the segments. But if this scenario comes, we are just ignoring the new newly compacted Segment. This is a problem maker when we work with MSLAB pool. The new segment would have acquired some chunks but when will they get released? As we dont close the segment this will leak them.

Also in swap we have

public boolean swap(VersionedSegmentsList versionedList, ImmutableSegment segment) {
    if(versionedList.getVersion() != version) {
      return false;
    }
    LinkedList<ImmutableSegment> suffix;
    synchronized (pipeline){
      if(versionedList.getVersion() != version) {
        return false;
      }

I dont see any possibility for this code flow to happen. Still for correctness, we should close the segment here too.