@Override
  public synchronized void setRPC(String methodName, Object[] params, long queueTime) {
    this.methodName = methodName;
    this.params = params;
    long now = EnvironmentEdgeManager.currentTime();
    this.rpcStartTime = now;
    setWarnTime(now);
    this.rpcQueueTime = queueTime;
    this.state = State.RUNNING;
  }
Tells this instance that it is monitoring a new RPC call.
@param methodName The name of the method that will be called by the RPC.
@param params     The parameters that will be passed to the indicated method.
hbase-server/src/main/java/org/apache/hadoop/hbase/monitoring/MonitoredRPCHandlerImpl.java