Reactive and Imperative Context Propagation in Spring Applications by Dariusz Jędrzejczyk

Applications have relied on contextual data that is outside of core business logic for a long time to provide vital insight into what the application is doing. Traditionally, Java applications built on the ThreadLocal construct to aggregate meta and observability information. With the introduction of asynchrony to the processing, it became easy to lose the precious, contextual data.
After providing the background behind current design and implementation of context support in Project Reactor, we’ll move to practical aspects that Spring application developers face. We’ll introduce a new Context Propagation library under Micrometer, which provides new and essential capabilities for bridging reactive and imperative programming styles. Reactor 3.5 has dedicated support for interacting with these concepts.
Next, we’ll cover how Reactor uses Micrometer 1.10’s Observation feature to provide metrics, tracing, and logging and how library implementers can take advantage of these patterns.

[@Muescha]

24:00 if you replay the code: you need to add: implementation 'io.micrometer:context-propagation:1.0.2' to the gradle file to get the ContextRegistry

[@Muescha]

34:00 if you replay the code: and the WebFilter is not invoked -> maybe you forget to reload the gradle setup when you comment out the spring boot starter web in the gradle file

[@ksoot]

Thanks for the Demo. It looks good when you are making just one call at a time, but things may fall apart when u make multiple parallel call to API, the their trace id and span id gets mixed up. Need to confirm that

[@jeet987]

Have you tried playing with this ? Even i suspect there could be mix up or MDC ctx getting lost , which i have seen with my webflux apps

[@sfshtirlitz]

What about calling another microservice using webClient and not just reading the file? It would be great to see the same traceId on the other side of webClient call? And that's what would make it "distributed"...

[@shubhamkesri6859]

I am also looking to handle a similar kind of issue, did you find any resources for it ?

[@Muescha]

could you add the link to the example code to the description?

[@Muescha]

i can not post a link into the comments, because then all my comments will be deleted.

[@skkchoudhary]

Can u plz share your example code or git location

[@Piontek.k]

Wtf are those scratch noises?

[@hareepjoshi]

this was a complete waste of time.