RPC server:

import pikaimport timeconnection = pika.BlockingConnection(pika.ConnectionParameters(        host='localhost')) channel = connection.channel() channel.queue_declare(queue='rpc_queue') def fib(n):    if n == 0:        return 0    elif n == 1:        return 1    else:        return fib(n-1) + fib(n-2) def on_request(ch, method, props, body):    n = int(body)     print(" [.] fib(%s)" % n)    response = fib(n)     ch.basic_publish(exchange='',                     routing_key=props.reply_to,                     properties=pika.BasicProperties(correlation_id = \                                                         props.correlation_id),                     body=str(response))    ch.basic_ack(delivery_tag = method.delivery_tag) channel.basic_qos(prefetch_count=1)channel.basic_consume(on_request, queue='rpc_queue') print(" [x] Awaiting RPC requests")channel.start_consuming()

RPC client:

import pikaimport uuid class FibonacciRpcClient(object):    def __init__(self):        self.connection = pika.BlockingConnection(pika.ConnectionParameters(                host='localhost'))         self.channel = self.connection.channel()         result = self.channel.queue_declare(exclusive=True)        self.callback_queue = result.method.queue         self.channel.basic_consume(self.on_response, no_ack=True,                                   queue=self.callback_queue)     def on_response(self, ch, method, props, body):        if self.corr_id == props.correlation_id:            self.response = body     def call(self, n):        self.response = None        self.corr_id = str(uuid.uuid4())        self.channel.basic_publish(exchange='',                                   routing_key='rpc_queue',                                   properties=pika.BasicProperties(                                         reply_to = self.callback_queue,                                         correlation_id = self.corr_id,                                         ),                                   body=str(n))        while self.response is None:            self.connection.process_data_events()        return int(self.response) fibonacci_rpc = FibonacciRpcClient() print(" [x] Requesting fib(30)")response = fibonacci_rpc.call(30)print(" [.] Got %r" % response)

以上为rpc示例。

基于rpc的主机管理程序要点有两个:

1 每个server的ip为一个queue,针对该主机的命令都放入该queue。

2 在给server端发送命令的同时,发送一个由uuid生成的queue名称,然后将该queue返回给用户。

3 将命令的执行结果存入由uuid生成的queue里。

4 客户端执行check命令取得执行结果。