public void updateRegionState(RegionInfo regionInfo, State state) {
    RegionStateNode regionNode = getOrCreateRegionStateNode(regionInfo);
    regionNode.lock();
    try {
      regionNode.setState(state);
    } finally {
      regionNode.unlock();
    }
  }
Called after we've split all logs on a crashed Server.
@see #logSplitting(ServerName)
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStates.java