@Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!(obj instanceof RegionState)) {
      return false;
    }
    RegionState tmp = (RegionState) obj;
    return RegionInfo.COMPARATOR.compare(tmp.hri, hri) == 0 && tmp.state == state
      && ((serverName != null && serverName.equals(tmp.serverName))
        || (tmp.serverName == null && serverName == null));
  }
Check if two states are the same, except timestamp
hbase-client/src/main/java/org/apache/hadoop/hbase/master/RegionState.java