当客户和工作人员分开时，负载平衡代理不起作用？

Question

alltogether.py

from __future__ import print_function

import threading
import time
import zmq

NBR_CLIENTS = 10
NBR_WORKERS = 3

def worker_thread(worker_url, context, i):
    """ Worker using REQ socket to do LRU routing """

    socket = context.socket(zmq.REQ)

    # Set the worker identity
    socket.identity = (u"Worker-%d" % (i)).encode('ascii')

    socket.connect(worker_url)

    # Tell the borker we are ready for work
    socket.send(b"READY")

    try:
        while True:

            address = socket.recv()
            empty = socket.recv()
            request = socket.recv()

            print("%s: %s\n" % (socket.identity.decode('ascii'), request.decode('ascii')), end='')

            socket.send(address, zmq.SNDMORE)
            socket.send(b"", zmq.SNDMORE)
            socket.send(b"OK")

    except zmq.ContextTerminated:
        # context terminated so quit silently
        return

def client_thread(client_url, context, i):
    """ Basic request-reply client using REQ socket """

    socket = context.socket(zmq.REQ)

    socket.identity = (u"Client-%d" % (i)).encode('ascii')

    socket.connect(client_url)

    #  Send request, get reply
    socket.send(b"HELLO")
    reply = socket.recv()

    print("%s: %s\n" % (socket.identity.decode('ascii'), reply.decode('ascii')), end='')

def main():
    """ main method """

    url_worker = "inproc://workers"
    url_client = "inproc://clients"
    client_nbr = NBR_CLIENTS

    # Prepare our context and sockets
    context = zmq.Context()
    frontend = context.socket(zmq.ROUTER)
    frontend.bind(url_client)
    backend = context.socket(zmq.ROUTER)
    backend.bind(url_worker)

    # create workers and clients threads
    for i in range(NBR_WORKERS):
        thread = threading.Thread(target=worker_thread, args=(url_worker, context, i, ))
        thread.start()

    for i in range(NBR_CLIENTS):
        thread_c = threading.Thread(target=client_thread, args=(url_client, context, i, ))
        thread_c.start()

    # Logic of LRU loop
    # - Poll backend always, frontend only if 1+ worker ready
    # - If worker replies, queue worker as ready and forward reply
    # to client if necessary
    # - If client requests, pop next worker and send request to it

    # Queue of available workers
    available_workers = 0
    workers_list      = []

    # init poller
    poller = zmq.Poller()

    # Always poll for worker activity on backend
    poller.register(backend, zmq.POLLIN)

    # Poll front-end only if we have available workers
    poller.register(frontend, zmq.POLLIN)

    while True:

        socks = dict(poller.poll())

        # Handle worker activity on backend
        if (backend in socks and socks[backend] == zmq.POLLIN):

            # Queue worker address for LRU routing
            worker_addr  = backend.recv()

            assert available_workers < NBR_WORKERS

            # add worker back to the list of workers
            available_workers += 1
            workers_list.append(worker_addr)

            #   Second frame is empty
            empty = backend.recv()
            assert empty == b""

            # Third frame is READY or else a client reply address
            client_addr = backend.recv()

            # If client reply, send rest back to frontend
            if client_addr != b"READY":

                # Following frame is empty
                empty = backend.recv()
                assert empty == b""

                reply = backend.recv()

                frontend.send(client_addr, zmq.SNDMORE)
                frontend.send(b"", zmq.SNDMORE)
                frontend.send(reply)

                client_nbr -= 1

                if client_nbr == 0:
                    break  # Exit after N messages

        # poll on frontend only if workers are available
        if available_workers > 0:

            if (frontend in socks and socks[frontend] == zmq.POLLIN):
                # Now get next client request, route to LRU worker
                # Client request is [address][empty][request]
                client_addr = frontend.recv()

                empty = frontend.recv()
                assert empty == b""

                request = frontend.recv()

                #  Dequeue and drop the next worker address
                available_workers -= 1
                worker_id = workers_list.pop()

                backend.send(worker_id, zmq.SNDMORE)
                backend.send(b"", zmq.SNDMORE)
                backend.send(client_addr, zmq.SNDMORE)
                backend.send(b"", zmq.SNDMORE)
                backend.send(request)

    # Out of infinite loop: do some housekeeping

    frontend.close()
    backend.close()
    context.term()

if __name__ == "__main__":
    main()

以上工作原理。

cycrh6rtp35.rtp.netapp.com{}: ./alltogether.py

    Worker-1: HELLO
    Worker-0: HELLO
    Worker-2: HELLO
    Client-0: OK
    Client-1: OK
    Worker-1: HELLO
    Worker-0: HELLO
    Client-2: OK
    Worker-2: HELLO
    Client-5: OK
    Client-4: OK
    Worker-1: HELLO
    Worker-2: HELLO
    Client-3: OK
    Client-6: OK
    Worker-0: HELLO
    Worker-1: HELLO
    Client-7: OK
    Client-8: OK
    Client-9: OK

我想把逻辑分成三个py文件
一个为工人
一个客户端 一个经纪人

broker.py

def do_lb():
    url_worker = "inproc://workers"
    url_client = "inproc://clients"
    client_nbr = NBR_CLIENTS

    # Prepare our context and sockets
    context = zmq.Context()
    frontend = context.socket(zmq.ROUTER)
    frontend.bind(url_client)
    backend = context.socket(zmq.ROUTER)
    backend.bind(url_worker)

    # create workers and clients threads
    #raw_input("Press Enter to continue...")
    #print 'continuing...'

    # Logic of LRU loop
    # - Poll backend always, frontend only if 1+ worker ready
    # - If worker replies, queue worker as ready and forward reply
    # to client if necessary
    # - If client requests, pop next worker and send request to it

    # Queue of available workers
    available_workers = 0
    workers_list      = []

    # init poller
    poller = zmq.Poller()

    # Always poll for worker activity on backend
    poller.register(backend, zmq.POLLIN)

    # Poll front-end only if we have available workers
    poller.register(frontend, zmq.POLLIN)

    while True:
        print 'in while true loop'
        socks = dict(poller.poll())

        print 'out1'
        # Handle worker activity on backend
        if (backend in socks and socks[backend] == zmq.POLLIN):
            print 'out11'
            # Queue worker address for LRU routing
            worker_addr  = backend.recv()
            assert available_workers < NBR_WORKERS

            # add worker back to the list of workers
            available_workers += 1
            workers_list.append(worker_addr)

            print 'out12'
            #   Second frame is empty
            empty = backend.recv()
            assert empty == b""

            print 'out13'
            # Third frame is READY or else a client reply address
            client_addr = backend.recv()

            # If client reply, send rest back to frontend
            if client_addr != b"READY":

                # Following frame is empty
                empty = backend.recv()
                assert empty == b""

                reply = backend.recv()

                frontend.send(client_addr, zmq.SNDMORE)
                frontend.send(b"", zmq.SNDMORE)
                frontend.send(reply)

                client_nbr -= 1

                if client_nbr == 0:
                    break  # Exit after N messages

        print 'out2'
        # poll on frontend only if workers are available
        if available_workers > 0:
            print 'workers are available'
            if (frontend in socks and socks[frontend] == zmq.POLLIN):
                # Now get next client request, route to LRU worker
                # Client request is [address][empty][request]
                client_addr = frontend.recv()

                empty = frontend.recv()
                assert empty == b""

                request = frontend.recv()

                #  Dequeue and drop the next worker address
                available_workers -= 1
                worker_id = workers_list.pop()

                backend.send(worker_id, zmq.SNDMORE)
                backend.send(b"", zmq.SNDMORE)
                backend.send(client_addr, zmq.SNDMORE)
                backend.send(b"", zmq.SNDMORE)
                backend.send(request)
        else:
            print 'workers are not available'

    # Out of infinite loop: do some housekeeping

    frontend.close()
    backend.close()
    context.term()

worker.py

import random
import sys
import threading
import time

import zmq

# using inproc
def worker_thread(context, i):
    """ Worker using REQ socket to do LRU routing """

    print 'creating worker %s' % i
    worker_url = "inproc://workers"
    socket = context.socket(zmq.REQ)
    # Set the worker identity
    socket.identity = (u"Worker-%d" % (i)).encode('ascii')
    socket.connect(worker_url)

    # Tell the borker we are ready for work
    socket.send(b"READY")

    try:
        while True:
            print 'in a while true loop, waiting...'
            address = socket.recv()
            empty = socket.recv()
            request = socket.recv()

            print("%s: %s\n" % (socket.identity.decode('ascii'), request.decode('ascii')))

            socket.send(address, zmq.SNDMORE)
            socket.send(b"", zmq.SNDMORE)
            socket.send(b"OK")

    except zmq.ContextTerminated:
        # context terminated so quit silently
        return

和client.py

import random
import sys
import threading
import time

import zmq

#using inproc
def client_thread(context, i):
    """ Basic request-reply client using REQ socket """

    print 'creating client %s' % i
    client_url = "inproc://clients"
    socket = context.socket(zmq.REQ)
    socket.identity = (u"Client-%d" % (i)).encode('ascii')
    socket.connect(client_url)

    #  Send request, get reply
    print 'sending hello'
    socket.send(b"HELLO")
    reply = socket.recv()

    print("%s: %s\n" % (socket.identity.decode('ascii'), reply.decode('ascii')))

我首先启动了broker.py，然后是workers.py，然后是clients.py，它们只是挂起并且什么都不做。

任何人都知道为什么？