Exception of type 'RabbitMQ.Client.Exceptions.PublishException' was thrown

[plewam]

Hi All,

I am currently testing around with 7.0.0-rc.12. However (I may be doing something wrong) I am no longer able to publish messages. I received a PublishException but do not get any further information with that. The exception does not contain any further info. Are you able to help?

I use RMQ Server 4.0.2 with Erlang 26.2.5.4

RabbitMQ.Client.Exceptions.PublishException: Exception of type 'RabbitMQ.Client.Exceptions.PublishException' was thrown.
   at RabbitMQ.Client.Impl.ChannelBase.BasicPublishAsync[TProperties](String exchange, String routingKey, Boolean mandatory, TProperties basicProperties, ReadOnlyMemory`1 body, CancellationToken cancellationToken)

[plewam]

Right... I found the issue. The below configuration causes the issue.

CreateChannelOptions channelOptions = new()
{
    PublisherConfirmationsEnabled = true,
    PublisherConfirmationTrackingEnabled = true
};

Changing it to makes it work again.

CreateChannelOptions channelOptions = new()
{
    PublisherConfirmationsEnabled = true,
    PublisherConfirmationTrackingEnabled = false
};

[lukebakken]

Hello! Thank you for the report. This is very strange, since the test suite uses this configuration all over the place:

    PublisherConfirmationsEnabled = true,
    PublisherConfirmationTrackingEnabled = true

Is the stack trace you posted the complete stack?

If you can share code to reproduce, that would be great. I'll look into this today.

[plewam]

Yes it sadly is. I even debugged it to gather more information.

[lukebakken]

Thanks, I'll get back on this today, hopefully. I really appreciate you testing the releases as they come out.

[lukebakken]

@plewam is there a chance that, in your environment, you're always getting Nacks from RabbitMQ? I realize this is unlikely.

Are you publishing with mandatory: true?

[lukebakken]

OK, you will get PublishException when mandatory: true and a message can't be routed to any queues. Does that happen to be the case?

Like I said, the test suite enables confirms and confirm tracking all over the place so I think this particular issue has something to do with your environment...?

[plewam]

I will have it checked shortly, give me a few days. If that is the case a publish exception is the right thing to do inside the library.

thanks for your help!

[lukebakken]

OK, thank you again for testing!

[plewam]

So I tested it again. Your library behaves correctly. I had the mandatory flag set and no queue bound to my destination exchange. Therefore it is correct to throw the PublishException. Thanks again for your help and assistance.

[lukebakken]

Thanks for the follow-up! I'm happy to assist, anytime.

[romerod]

Is this https://github.com/rabbitmq/rabbitmq-tutorials/blob/main/dotnet/PublisherConfirms/PublisherConfirms.cs example still ok?

It's not catching the PublishException which is thrown by BasicPublishAsync now, but relying on the BasicReturnAsync?

Is PublishException enough now to know that message was not routed?

[michaelklishin]

As file history suggests, it was updated for the 7.x series of the client.

There's also tutorial 7 that focuses on publisher confirms specifically.

Publisher confirms are orthogonal to unroutable message handling.

[romerod]

Ah ok, thank you
The code rabbitmq/rabbitmq-tutorials@a4adce9 where PublishException was explicitly catched seemed to make more sense for me, but ok.

Thanks