build_info gauge metric behavior differs since 0.43

[garethpelly]

A note for the community

• Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request
• If you are interested in working on this issue or have submitted a pull request, please leave a comment

Problem

Since 0.43, the build_info gauge metric is not emitting the last known value "1" indefinitely. As a result, it appears only once at start up and therefore this impacts the ability to monitor the counts of vector pods and their respective versions.

I noticed that the "metrics" dependency was updated from 0.24.0 to 0.24.1 in the 0.43 release but I can't spot what has changed to impact the behaviour.

Configuration

No response

Version

0.43

Debug Output

No response

Example Data

No response

Additional Context

No response

References

No response

[jszwedko]

Ah, this is likely the result of #20710 which change the default for the registry to expire entries (to avoid leaking). As a workaround, you can set https://vector.dev/docs/reference/configuration/global-options/#expire_metrics_secs to -1 to restore the previous default behavior of not expiring metrics.

The real fix is for this metric to be emitted on an interval so it doesn't expire.

[jszwedko]

I'm also noticing this didn't end up in the release changelog for some reason 🤔

[jszwedko]

Oh I see, because it is a chore which are skipped when rendering. I opened #21990 to fix the rendering.

[pront]

Oh I see, because it is a chore which are skipped when rendering. I opened #21990 to fix the rendering.

Interesting... good catch.

[jszwedko]

Fix: #21991