@Override
    public Message callBlockingMethod(Descriptors.MethodDescriptor md, RpcController controller,
      Message param, Message returnType) throws ServiceException {
      return rpcClient.callBlockingMethod(md, configureRpcController(controller), param, returnType,
        ticket, addr);
    }
Blocking rpc channel that goes via hbase rpc.
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java