[HBASE-18619] Should we add a postOpenDeployTasks after open splited or merged region?

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.98.6, 1.4.0, 1.2.6, 1.1.11
• Component/s: Region Assignment
• Assignee: Jingyun Tian
• Reporter: Jingyun Tian
• Created: 17/Aug/17 10:26
• Updated: 07/Dec/17 18:24

Description

I have a question that why we skip postOpenDeployTasks() when we not using zk for assignment?

      if (services != null) {
        try {
          if (useZKForAssignment) {
            // add 2nd daughter first (see HBASE-4335)
            services.postOpenDeployTasks(b);
          } else if (!services.reportRegionStateTransition(TransitionCode.SPLIT,
              parent.getRegionInfo(), hri_a, hri_b)) {
            throw new IOException("Failed to report split region to master: "
              + parent.getRegionInfo().getShortNameToLog());
          }
          // Should add it to OnlineRegions
          services.addToOnlineRegions(b);
          if (useZKForAssignment) {
            services.postOpenDeployTasks(a);
          }
          services.addToOnlineRegions(a);
        } catch (KeeperException ke) {
          throw new IOException(ke);
        }
      }

It causes a new splitted region or new merged region will not compact their reference files. Then if the normalizer thread want to split this region, it will get stuck.

public boolean canSplit() {
    this.lock.readLock().lock();
    try {
      // Not split-able if we find a reference store file present in the store.
      boolean result = !hasReferences();
      if (!result && LOG.isDebugEnabled()) {
        LOG.debug("Cannot split region due to reference files being there");
      }
      return result;
    } finally {
      this.lock.readLock().unlock();
    }
  }

According to the code, should we add a services.postOpenDeployTasks after successfully reportRegionStateTransition(TransitionCode.SPLIT, parent.getRegionInfo(), hri_a, hri_b) ?

Issue Links

• is related to: HBASE-11059 ZK-less region assignment
• is related to: HBASE-11546 Backport ZK-less region assignment to 0.98