MSMQ requires error queue configuration for send-only endpoints

[boblangley]

Who's affected

Anyone using the MSMQ transport with send-only endpoints on NServiceBus 6.3.

Symptoms

After upgrading to 6.3, users need to configure a error queue unnecessarily.

Original bug report

This is a change in behavior and has broken the Azure dynamic host, which launches the endpoint as a sendonly endpoint.

[boblangley]

This line should include a check to see if the endpoint is not configured as a SendOnly endpoint: https://github.com/Particular/NServiceBus/blob/master/src/NServiceBus.Core/Transports/Msmq/MsmqTransport.cs#L35

[SeanFeldman]

I've raised a PR against MSMQ transport: Particular/NServiceBus.Transport.Msmq#25

[andreasohlund]

Would we classify this as a patch?

[SeanFeldman]

I'd say so. Qualifies at least a Minor Patch criteria as azure multi host would require to take the host offline, add an error queue configuration and redeploy. That's quite a workaround 😃

[andreasohlund]

How can the azure multi host be affected by a msmq bug?

[yvesgoeleven]

@andreasohlund as discussed on slack, it's probably because msmq is on by default as the host doesn't have a need for a transport

[bording]

Reopening since we still need to consider a 6.3.x patch.

[SimonCropp]

wouldnt this always fail at startup? in which case it could never get to production? and if so not a back port

[bording]

@SimonCropp It's not a backport. It's a fix to a regression introduced in 6.3.0

[SimonCropp]

@bording ok thanks for the clarification

[bording]

Fixed by #4784