OPA server - prometheus histogram buckets configuration

[AdrianArnautu]

Hi folks,

OPA exposes a prometheus histogram http_request_duration_seconds for the request duration, with only a handful of buckets.
From https://github.com/open-policy-agent/opa/blob/main/internal/prometheus/prometheus.go#L47 and from the :8181/metrics

1e-6, // 1 microsecond
5e-6,
1e-5,
5e-5,
1e-4,
5e-4,
1e-3, // 1 millisecond
0.01,
0.1,
1, // 1 second

Is there any way the buckets can be set from the config? Did I missed that out from the documentation/code?

[srenatus]

Right now, bucket sizes are not configurable, sorry.

[charlieegan3]

If you'd like to open a new issue for this with some details about your use case that'd be interesting.

If it's a clear use case that other users have in common we could certainly consider it.

[AdrianArnautu]

thank you guys
we might lend a hand here in the near future, we need a better insight on what's going on at OPA level

[charlieegan3]

Happy to help in slack if you need help debugging a policy performance issue 🙂 (tomorrow!)

[AdrianArnautu]

I've raised open-policy-agent/opa#6238 that adds support for configuration