@Override
    protected void periodicExecute(final MasterProcedureEnv env) {
      final AssignmentManager am = env.getAssignmentManager();

      final RegionInTransitionStat ritStat = am.computeRegionInTransitionStat();
      if (ritStat.hasRegionsOverThreshold()) {
        for (RegionState hri : ritStat.getRegionOverThreshold()) {
          am.handleRegionOverStuckWarningThreshold(hri.getRegion());
        }
      }

      // update metrics
      am.updateRegionsInTransitionMetrics(ritStat);
    }
Check that what the RegionServer reports aligns with the Master's image. If disagreement, we
will tell the RegionServer to expediently close a Region we do not think it should have.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java