Clear/Stop embedded Tempo?

[stephanos]

I have a (closed source) Go application which visualizes OTEL traces as sequence diagrams; it embeds Tempo for managing the processing and querying of OTEL traces. Ant it works great!

Basically:

var tempo *app.App
// config ...
tempo, _ = app.New(*config)
tempo.Run()

But I have one use case I can't figure out how to solve: I need to reset Tempo's storage to get into a clean slate. The only way right now is to shutdown the entire app. I've tried deleting the storage files but Tempo doesn't like that (understandable).

I couldn't find any REST or Go API yet to clear out the data storage. Note that I don't want to change the retention, I'd like to clear everything at once at any moment in time.

I also couldn't see an API to stop the Tempo instance once I execute Run.

I'd appreciate any insight you could share!

[joe-elliott]

You're definitely running Tempo in a strange mode so I'm not surprised you're having issues. If there were a way to programmatically stop Tempo and all its subservices you could do that, wipe all the files and restart.

Perhaps look at the shutdown process? I'd support a PR to do a little refactoring if it makes your use case achievable and doesn't unnecessarily complicate Tempo.

[stephanos]

Thank you for your reply!

I took a look around and immediately I see two possible options. It appears the signals handler loop that waits for SIGTERM etc. blocks the shutdown of the app. So I'm thinking:

1. expose the signals handler on app.App (a couple of other modules are exported already) which would allow calling Stop on it
2. or add Stop as a method on app.App which internally calls Stop on the signals handler

(2) is arguably cleaner as it hides how the server is shutdown from the outside.

WDYT?

[stephanos]

Like this: main...stephanos:tempo:stop-tempo-app

[joe-elliott]

if this meets your needs i'd take that PR. thanks for looking into this 🙏