Multithread-Capable MDC about scribe

[darkfrog26]

Got tired of waiting. Released with 3.10.0

[kell18]

Hi! Thanks for the lib! As far as I can see it still will suffer from context switches? I.e. when a function executing in the future is getting moved to another execution thread? The MDC context for the function will not be preserved, right?

[darkfrog26]

So, this was a bit of a half-measure. In order to share the context, you'd have to MDC.contextualize(mdc) { ... } in the block you want to utilize it. I'll give this some more thought on coming up with a better way to do it. If you have any thoughts, they would be welcome.

[darkfrog26]

What would you think about me adding:

(implicit mdc: MDC = MDC.global)

to all logging calls and allow an implicit MDC to be able to be picked up?

[kell18]

Hmm, not many ideas from my side. But maybe it's not the task for the logging library if it was not initial design choice. I heard that it should be possible to do with custom ExecutionContexts but I never was able to make it working... https://blog.knoldus.com/how-to-use-mdc-logging-in-scala/

[darkfrog26]

I've added some new functionality to allow the use of implicits:

    MDC { implicit mdc =>
      mdc("key") = "value"
      val f = Future {
        scribe.info("this is a test")
      }
      Await.result(f, Duration.Inf)
    }

The above will output with "key" = "value" in the logs. Would you say this adequately solves the problem? Of course, if you're working across multiple methods you'd have to pass around the implicit MDC.

[darkfrog26]

@kell18 I'm planning to do a release this week, but I'd like confirmation that this update fulfills your needs?