[PROTON-1242] Sending at-most-once (presettled) messages with a delay between them does not work with BlockingConnection

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: proton-0.13.0
• Component/s: python-binding
• Environment: Red Hat Enterprise Linux 6.8 64bit, dispatch-router 0.6.0
• Assignee: Unassigned
• Reporter: Jiri Daněk
• Created: 21/Jun/16 10:54
• Updated: 05/Apr/17 12:47

Description

Messenger blocking API should work in combination with calls to time.sleep(). For example, if I wish to send certain number of messages with 0.5s delay between each, I should be able to write

messages = 5
host, path = address.split('/')
    conn = BlockingConnection(host)
    sender = conn.create_sender(path, options=AtMostOnce())
for i in range(messages):
        sender.send(Message(body="message %d" % i));
        time.sleep(0.5)

The code above does not work. I tried sending over Qpid Dispatch Router and receiving with the simple_recv.py example and all five messages arrived at once, after approx. 2 seconds of waiting.

If I leave out options=AtMostOnce(), then the code above works as expected and messages arrive one by one with the 0.5s delay.

Steps to reproduce:

python qpid-proton/examples/python/simple_recv.py -a 172.28.128.251/myaddress

python slow_presettled_send_blocking.py -a 172.28.128.251/myaddress -m 5