@Override
  public Optional<ServerName> getActiveMaster() {
    return Optional.ofNullable(masterAddressTracker.getMasterAddress());
  }
Return pause time configured in {@link HConstants#HBASE_RPC_SHORTOPERATION_RETRY_PAUSE_TIME}}
@return pause time
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java