Test LPMS refactoring on staging

[Quintendos]

[1] livepeer/lpms#347
[2] livepeer/lpms#348

(blocks transcoding work Diederik)

[Quintendos]

@AlexHevc brought up a really good point this morning that Michal's LPMS refactorings [1] [2] still haven't been rolled out and that this should probably be a precondition for the work @roxlu is doing.

The current state is that [1] is merged but behind a feature flag and so we should enable that flag on Staging and test

I think that after that, the steps are:

1. Gradually turn on the flag for our Prod Os and monitor
2. Remove the flag and cut a go-livepeer release for community Os
3. @AlexHevc and @roxlu to analyse [2] and either merge, test and roll out or cherry-pick bits they want to keep

[mjh1]

@thomshutt is this the correct place to add this env variable? orchestrator section..? https://github.com/livepeer/livepeer-infra/commit/e411d494bb171cb9d998c4138ac71d40d2dc7338

[thomshutt]

I think so, you should check if we have logging to confirm it's working though (and add it if we don't)

[mjh1]

I think so, you should check if we have logging to confirm it's working though (and add it if we don't)

@thomshutt do you think this will be ok: https://github.com/livepeer/lpms/pull/362/files
Obviously not great having a log line for every transcode but the log line would go away eventually when we remove the old implementation. Easiest alternative I can think of is just reading the same environment variable on startup in go-livepeer and logging it there 🤔

[thomshutt]

@mjh1 Yeah, that's fine - I just approved. In the grand scheme of the amount of logging we do, one line per transcode is fine.

[mjh1]

This was rolled out to staging today. Initial tests aren't showing any issues 👍

Confirmed with the log line that it's definitely in action:

$ kubectl logs staging-livepeer-orchestrator-1 | grep "LPMS new transcode enabled"
I0110 10:20:41.029146       1 ffmpeg.go:970] LPMS new transcode enabled

[thomshutt]

Holding off until we find the cause of extra frames that @AlexKordic saw being added in some cases