@Override
  public RpcChannel createRpcChannel(ServerName sn, User user, int rpcTimeout) {
    return new RpcChannelImplementation(this, createAddr(sn), user, rpcTimeout);
  }
Configure an hbase rpccontroller
@param controller              to configure
@param channelOperationTimeout timeout for operation
@return configured controller
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java