我一直在使用ZeroMQ的请求/响应套接字,以在Web应用程序和用于卸载处理的从属应用程序之间交换消息。我注意到在某些情况下,并非所有发送的ZMQ消息实际上都被另一端接收到。甚至奇怪的是,即使使用IPC协议,这种情况也会发生,我认为这是相当可靠的。

在不产生任何错误的情况下,导致未发送已发送消息的原因是什么?

这是客户端代码的示例:

# ironic
class ReliableClient(object):
    def _reconnect(self):
        if self.socket:
            self.socket.close()
            self.socket = None

        self.socket = self.context.socket(zmq.REQ)
        self.socket.connect(self.server_url)

        # Give the server 2 sec to respond
        self.socket.RCVTIMEO = 2000
        self.socket.SNDTIMEO = 2000

        self.socket.LINGER = 3

    def __init__(self, server_url=None, server_name=None):
        self.socket = None
        self.server_url = server_url

        if server_name is None:
            self.server_name = server_url
        else:
            self.server_name  = server_name

        self.lock = threading.Lock()
        self.context = zmq.Context()

        self._reconnect()

    def msg(self, msg):
        raw_out = dumps(msg)

        # send
        self.lock.acquire()
        try:
            self.socket.send(
                raw_out,
                copy=True
            )
        except zmq.ZMQError as ex:
            log.exception(ex, '%s: failed to send', self.server_name)
            self.lock.release()
            raise CommunicationError('failed to send')

        # receive
        try:
            raw_in = self.socket.recv()
        except zmq.ZMQError as ex:
            log.exception(ex, '%s: failed to receive', self.server_name)
            raise CommunicationError('failed to receive')
        finally:
            self.lock.release()

        msg_in = loads(raw_in)

        return msg_in

最佳答案

我对IPC协议不熟悉,但是我已经广泛使用ZMQ / TCP。

如果正确使用TCP,即使是基于TCP的最简单的ZMQ REQ / REP模式也永远不会丢弃消息。如果您的网络连接或远程端点断开,它可能会无限期挂起,但它绝不会默默地失败。在某些情况下,某些套接字在设计上会丢弃消息。例如,某些邮件可能会在达到HWM时丢弃消息。

关于python - ZeroMQ的可靠性?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/18236368/

10-13 01:22