Metrics

[estahn]

I would like to expose some metrics about the state of the pool in my application, e.g. the number of items in the backlog, the number of workers, etc.

Thoughts?

[alitto]

Hey @estahn!

So far, only 2 metrics are exposed by pools:

• pool.Running(): returns the number of active/running worker goroutines (gauge)
• pool.Idle(): returns the number of idle worker goroutines (gauge)

The number of worker goroutines currently executing a task can be calculated as pool.Running() - pool.Idle().

It would be very useful to expose more metrics, such as:

• pool.MaxWorkers(): Max number of workers (constant/gauge)
• pool.MinWorkers(): Min number of workers (constant/gauge)
• pool.SubmittedCount(): Number of tasks submitted since the pool was created (counter)

If you think of any other metric that could be useful please let me know. I might send a PR to add these soon.

[alitto]

FYI @estahn, v1.5.0 is out and it adds a number of useful metrics to worker pools, see https://github.com/alitto/pond#metrics--monitoring for more info. I've also added an example to show how these can be exposed to Prometheus
Cheers

[estahn]

@alitto Awesome, thanks. I will check it out soon. I'm using your lib here btw: https://github.com/estahn/k8s-image-swapper

[alitto]

That's great man! nice tool, certainly very useful now that Docker hub rate limits pulls 🙂