Hey Quick question from me surrounding best practices I have

Question

Hey Quick question from me surrounding best practices I have a spring boot application and I want to add a sessionId onto each request for simplicity let s say i want to a unique id for each query what s the intended way of doing this with contexts directives etc Especially if we re adding this unique Id onto MDC where would you thing it natural to put the MDC put session and MDC remove session

Dariusz Kuc · Answer

It is a pretty common use case especially with something like tracing Underlying problem is how to store it so it is available for the whole session With Spring MVC apps you could use something like `ThreadLocals` to store it which MDC relies on With WebFlux which we use in `graphql kotlin spring server` you have reactor subscriber context and coroutine context through interop

Dariusz Kuc · Answer

Unfortunately though is that since we rely on `graphql java` execution logic we jump between reactor coroutines and `CompletableFuture` which don t have any contextual information One way to solve it is to create your custom `GraphQLServer` which populates MDC and other contextual data and then wraps the execution in your coroutine context You then would also need to create custom `DataFetcher` I d extend that propagates the coroutine context when invoking suspendable functions

Dariusz Kuc · Answer

Thats actually what we do internally in our servers

Dariusz Kuc · Answer

Personally I d also store that ID in the GraphQL context object which is bound to the whole GraphQL request and can be retrieved easily from environment e g so you could use it from instrumentations etc

Anders Kirkeby · Answer

I see thinking face Ye I was curious since it seems like a very common use case but it makes sense when you explain it like that Thanks for the pointers I ll look into doing something like that slightly smiling face

Dariusz Kuc · Answer

crossed fingers one day will have time to rewrite that execution logic to coroutines and drop the completable future dependency

Anders Kirkeby · Answer

That would indeed be amazing pray

Robert · Answer

Spring WebFlux Reactor provides some ways to do it <https piotrminkowski com 2019 10 15 reactive logging with spring webflux and logstash >