Question

I need to be able to gracefully stop a consumer (worker) who works in a Pika ioloop. The worker should stop after 60 seconds. Currently processed messages should be finished.

I tried to put a connection.close() inside the callback function but that only stopped the current thread and not the complete ioloop. And it gave a terrible error output.

Please see line 16 and following in my code: I used the (basic example about Pika ioloop http://pika.github.com/connecting.html#cps-example:

    from pika.adapters import SelectConnection
    channel = None
    def on_connected(connection):
        connection.channel(on_channel_open)

    def on_channel_open(new_channel):
        global channel
        channel = new_channel
        channel.queue_declare(queue="test", durable=True, exclusive=False, auto_delete=False, callback=on_queue_declared)

    def on_queue_declared(frame):
        channel.basic_consume(handle_delivery, queue='test')

    def handle_delivery(channel, method, header, body):
        print body

        # timer stuff which did NOT work
        global start_time, timeout, connection
        time_diff = time.time()-start_time
        if time_diff > timeout:
            #raise KeyboardInterrupt
            connection.close()

    timeout = 60
    start_time = time.time()

    connection = SelectConnection(parameters, on_connected)

    try:
        connection.ioloop.start()
    except KeyboardInterrupt:
        connection.close()
        connection.ioloop.start()

Answer 1

You can attach a timeout call-back function on the opened connection.
Here is the extra code for your example.

timeout = 60

def on_timeout():
  global connection
  connection.close()

connection.add_timeout(timeout, on_timeout)