Understanding of Contexts in smallrye reactive messaging

[dankristensen]

We do not quite understand how the context propagation is working, when we use @Blocking in an @inbound message handler.

See this reproducer repo: https://github.com/JakobTveen/mdc-context-propagation

We are populating a correlationId in a MessageHeader, and want to assign it to MDC when we have received the message. We get the correct value, but when setting it and then getting it again, it ALWAYS returns null.

If we remove @Blocking, it is working fine.

Can anybody explain this behaviour? And possibly come with a suggestion to how we can do it when having the @Blocking annotation applied.

[cescoffier]

\CC @ozangunalp