Unexpected PRECONDITION_FAILED

[David Brown]

I must be doing something wrong.

Using AWS's hosted RabbitMQ, I am processing simple messages and manually acking them using noAck: false for the queue and channel.ack(msg) to acknowledge them. However, after 30 minutes of inactivity I see:

channel 1 closed 406 PRECONDITION_FAILED - delivery acknowledgement on channel 1 timed out. Timeout value used: 1800000 ms. This timeout value can be configured, see consumers doc guide to learn more 0 0

I am fairly certain I have acked all messages, and in our staging environment where I can control all traffic I can see that all queues are empty:

What else should I be checking to understand why I'm getting this timeout? Does it also happen when there is no activity for the timeout duration?

[Luke Bakken]

Hello,

Please let us know the following:

• RabbitMQ and Erlang version
• Client library used and version
• Code sample. A complete one that could be run to observe the issue would be great.

My guess given the limited information is that you are not ack-ing messages using the correct delivery tag.

Thanks,

Luke

[David Brown]

Thank you for your response.

Amazon reports broker version 3.8.22. That looks a bit old; we will need to look into updating that. I don't see a way to find the Erlang version.

This specific behavior was observed with the latest amqp-client (2.1.1).

Before I spend the time coming up with a code sample I wonder if it makes more sense to get on a more recent version of the broker?

[Luke Bakken]

Hello,

It's very unlikely this is a bug in the broker. However, version 3.8 is out of support so upgrading to the latest version would be a good idea.

I'll keep an eye out for a way to reproduce this issue.

Thanks,

Luke