Channel error handling on passive queue declaration

[bhoehl]

When declaring a queue, which is not yet declared, using passive=True, an error is raised and the channel ought to be closed. The code behaves as if so, but continuing using channels is causing an error on the server:

• operation channel.open caused a connection exception channel_error: "second 'channel.open' seen"

What can also be observed, is that the RabbitMQ server ( 3.7.8) is listing the channel after this error as open in the admin web UI. The error can easily be reproduced by establishing a RabbitMQ connection and using this code snippet:

try:
    channel = conn.channel()
    channel.queue.declare('test', passive=True)
except Exception as e:
    print(str(e))
    # Channel 1 was closed by remote server: NOT_FOUND - no queue 'test' in vhost '/'
    # this is not true, as the channel is still listed in the web user interface ( 15672 )

# Further calls to get a new or other channel also fail, because the channel id is reused
channel = conn.channel()
# is causing an error on the server
# operation channel.open caused a connection exception channel_error: "second 'channel.open' seen"
# because it is still open
# the program hangs at this point and does not return from conn.channel()

There is no chance of handling this, except closing the whole connection. I would consider this a bug. Please check, if you can reproduce. Btw. it does not matter if you add channel.close() or use with in between. Even the latest RabbitMQ version 3.9.9 behaves the same.

[eandersson]

Thanks for the report. There is definitely something wrong here.

[eandersson]

Figured it out. I'll get a patch out this weekend. The issue is that we do not send a CloseOk back when the channel is forcefully closed, so the second channel is still waiting for that message, causing it to get into a weird state.