使用Python3和Stomp，如何禁用activemq的预取？

Question

I'm designing a distributed project, on win10. However all messages goes to one consumer with below code. It caches all before handling them. What is the correct way to to that?

# -*-coding:utf-8-*-
import stomp
import time

#http://localhost:8161 

queue_name = '/queue/SampleQueue'
topic_name = '/topic/SampleTopic'
listener_name = 'SampleListener'

class SampleListener(object):
    def on_message(self, headers, message):
        print ('headers: %s' % headers)
        print ('message: %s' % message)
        time.sleep(1) # blocking consumer here

def send_to_queue(msg):
    conn = stomp.Connection10([('127.0.0.1',61613)])
    conn.start()
    conn.connect()
    for i in range(50):
        conn.send(queue_name, msg)
    conn.disconnect()

def receive_from_queue():
    conn = stomp.Connection10([('127.0.0.1',61613)])
    conn.set_listener(listener_name, SampleListener())
    conn.start()
    conn.connect()
    #conn.subscribe(queue_name, {'ack': 'client-individual', 'activemq.prefetchSize': 0})
    conn.subscribe(queue_name, {'activemq.prefetchSize':1, })

    time.sleep(600) # secs
    conn.disconnect()


if __name__=='__main__':
    if True:
        send_to_queue('sample text 123')
        receive_from_queue()

Answer 1

Some years ago, I used ActiveMQ and stompy (I know it's a different module or probably an older version of the module) and I had the same prefetching problem and I worked around it by setting ack='client' in the subscribe call: stomp.subscribe(SETTINGS.QUEUE, ack='client')

Looking at the docs , you should be able to do the same with the module you are using.

Here's part of my old code:

from stompy.simple import Client

destination = 'yourqueuehere'
settings = {} # some dictionary with the host, port, etc.; I forget exactly

stomp = Client(**settings)
stomp.connect()
stomp.subscribe(destination, ack='client')
try:
    while True:
        message = stomp.get()
        stomp.ack(message) # I have to call ack myself since I have ack='client' above
        # do something with message

finally:    
    stomp.unsubscribe(destination)
    stomp.disconnect()

I forgot what went in settings .