Why a ZeroMQ example does not work?

时间:2018-06-05 05:05:45

标签: python zeromq

I am new in Python/ ZeroMQ, so show forbearance if it is an easy question.

I try to run some examples, but it does not work really good.
Here is the hwserver/hwclient example of the ZeroMQ-Guide:


SERVER

#   Hello World server in Python
#   Binds REP socket to tcp://*:5555
#   Expects b"Hello" from client, replies with b"World"
#

import time
import zmq
context = zmq.Context()
socket = context.socket(zmq.REP)
socket.bind("tcp://*:5555")

while True:

    message = socket.recv()               #  Wait for next request from client
    print("Received request: %s" % message)

    time.sleep(1)                         #  Do some 'work'

    print( "teeest" )

    socket.send(b"World")                 #  Send reply back to client

CLIENT

#    Hello World client in Python
#    Connects REQ socket to tcp://localhost:5555
#    Sends "Hello" to server, expects "World" back
#

import zmq

context = zmq.Context()

print("Connecting to hello world server…")    #  Socket to talk to server
socket = context.socket(zmq.REQ)
socket.connect("tcp://localhost:5555")


for request in range(10):                     #  Do 10 requests,
    #                                         #  waiting each time for a response
    print("Sending request %s …" % request)
    socket.send(b"Hello")

    message = socket.recv()                   #  Get the reply.
    print("Received reply %s [ %s ]" % (request, message))

And I am getting this output:

Connecting to hello world server…
Sending request 0 …
Received reply 0 [ b'World' ]
Sending request 1 …
Received reply 1 [ b'World' ]
Sending request 2 …
Received reply 2 [ b'World' ]
Sending request 3 …
Received reply 3 [ b'World' ]
Sending request 4 …
Received reply 4 [ b'World' ]
Sending request 5 …
Received reply 5 [ b'World' ]
Sending request 6 …
Received reply 6 [ b'World' ]
Sending request 7 …
Received reply 7 [ b'World' ]
Sending request 8 …
Received reply 8 [ b'World' ]
Sending request 9 …
Received reply 9 [ b'World' ]

Process finished with exit code 0

Could somebody tell me why I dont get the prints of the server like "Received request" and "teeeest"?

Thank you!

2 个答案:

答案 0 :(得分:1)

  

为什么 我没有得到服务器的打印件,如“收到的请求”和“teeeest”?

那么,
你实际上得到了他们,
但是因为你没有看到正确的(两个)地方(s)(如果也从服务器端的PyCharm / Terminal窗口读取,你会看到'em - 这是一个好消息)。

欢迎使用 。有两个“角色”一起跳舞(在 REQ/REP 或其他ZeroMQ可扩展形式通信模式原型中编码),你必须检查分布式舞蹈的两面看全貌。

只观看一方让你没有完整的故事。

为了更容易看到这一点,让我们稍微修改一下代码:

SERVER MOD:

import time
import zmq
context = zmq.Context()
socket  = context.socket( zmq.REP ); socket.bind( "tcp://*:5555" )

while True:
    message = socket.recv()               #  Wait for next request from client
    print( "TERMINAL[1]: SERVER has received request: %s" % message )
    time.sleep(1)                         #  Do some 'work'
    print( "TERMINAL[1]: SERVER puts teeest......................." )

    socket.send( b"World" )               #  Send reply back to client

客户MOD:

import zmq

context = zmq.Context()

print( "TERMINAL[2] CLIENT says Connecting to hello world server…" )    

socket = context.socket( zmq.REQ )            #  Socket to talk to server
socket.connect( "tcp://localhost:5555" )

for request in range( 10 ):                   #  Do 10 requests,
    #                                         #  waiting each time for a response
    print( "TERMINAL[2] CLIENT Sending request %s …" % request )
    socket.send( b"Hello" )

    message = socket.recv()                   #  Get the reply.
    print( "TERMINAL[2] CLIENT Received reply %s [ %s ]" % ( request, message ) )

这个输出你已经“知道”了:

TERMINAL[2] CLIENT says Connecting to hello world server…
TERMINAL[2] CLIENT Sending request 0 …
TERMINAL[2] CLIENT Received reply 0 [ b'World' ]
TERMINAL[2] CLIENT Sending request 1 …
TERMINAL[2] CLIENT Received reply 1 [ b'World' ]
TERMINAL[2] CLIENT Sending request 2 …
TERMINAL[2] CLIENT Received reply 2 [ b'World' ]
TERMINAL[2] CLIENT Sending request 3 …
TERMINAL[2] CLIENT Received reply 3 [ b'World' ]
TERMINAL[2] CLIENT Sending request 4 …
TERMINAL[2] CLIENT Received reply 4 [ b'World' ]
TERMINAL[2] CLIENT Sending request 5 …
TERMINAL[2] CLIENT Received reply 5 [ b'World' ]
TERMINAL[2] CLIENT Sending request 6 …
TERMINAL[2] CLIENT Received reply 6 [ b'World' ]
TERMINAL[2] CLIENT Sending request 7 …
TERMINAL[2] CLIENT Received reply 7 [ b'World' ]
TERMINAL[2] CLIENT Sending request 8 …
TERMINAL[2] CLIENT Received reply 8 [ b'World' ]
TERMINAL[2] CLIENT Sending request 9 …
TERMINAL[2] CLIENT Received reply 9 [ b'World' ]

所以,
接下来只是看看另一个窗口/终端,
您将在哪里看到所有预期的SERVER端print() - s:

TERMINAL[1]: SERVER has received request: b'Hello'
TERMINAL[1]: SERVER puts teeest.......................
TERMINAL[1]: SERVER has received request: b'Hello'
TERMINAL[1]: SERVER puts teeest.......................
TERMINAL[1]: SERVER has received request: b'Hello'
TERMINAL[1]: SERVER puts teeest.......................
TERMINAL[1]: SERVER has received request: b'Hello'
TERMINAL[1]: SERVER puts teeest.......................
TERMINAL[1]: SERVER has received request: b'Hello'
TERMINAL[1]: SERVER puts teeest.......................
TERMINAL[1]: SERVER has received request: b'Hello'
TERMINAL[1]: SERVER puts teeest.......................
...

有兴趣尽快掌握ZeroMQ吗?

可以享受再进行5秒阅读 关于 [ ZeroMQ hierarchy in less than a five seconds ] 或其他帖子和讨论中的主要概念差异。

答案 1 :(得分:0)

客户端不应该打印teeest而是打印服务器,因为print( "teeest" )被指示在服务器文件中执行。

您的输出显示客户端的输出,但不显示服务器的输出。

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