为什么 ZeroMQ 示例不起作用？

Question

我是 Python/ ZeroMQ 的新手，所以如果这是一个简单的问题，请表现出宽容。

我尝试运行一些示例，但效果并不好。
这是 ZeroMQ 指南的 hwserver/hwclient 示例：

---

服务器

#   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

---

客户

#    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))

---

我得到这个输出：

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

有人可以告诉我为什么我没有得到服务器的打印信息，例如“已收到请求”和“teeeest”吗？

谢谢！

Answer 1

为什么我没有得到服务器的打印信息，例如“已收到请求”和“teeeest”？

嗯，你实际上确实得到了它们，但是因为你没有查看正确的（两者）地方（如果也从服务器端 PyCharm / 终端窗口阅读，你会看到它们_{——那就是好消息}）。

欢迎来到分布式计算。有两个“角色”一起跳舞（如

REQ/REP

或其他 ZeroMQ 可扩展正式通信模式原型中的编码），您必须检查 分布式舞蹈 的两侧才能看到整个情况。

只看一侧会让你看不到完整的故事。

为了使其更容易看到，让我们稍微修改一下代码：

---

服务器模式：

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

---

客户端模式：

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' ]

那么，
接下来只需查看另一个窗口/终端，
您将在其中看到所有预期的服务器端

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？

您可以用 5 秒的时间进一步阅读 ZeroMQ 层次结构中的主要概念差异（不到 5 秒） 或其他帖子和讨论。

Answer 2

打印

teeest

的不是客户端，而是服务器，因为

print( "teeest" )

是在服务器文件中指示执行的。

您的输出显示客户端的输出，而不是服务器的输出。