Clean raw data metrics that do not receive measures

[rafaelweingartner]

The truncating of the raw metrics data is only done when new measures are pushed. Therefore, if no new measures are pushed, and the archive policy is updated to reduce the back window, the raw data points for metrics that are not receiving new data points are never truncated.

The goal of this PR is to propose a method to identify metrics that are in "inactive state", meaning, not receiving new data points, and execute their raw data points truncation when the archive policy backwindow is changed.

[rafaelweingartner]

Thanks @chungg for the review!

I address the points you raised, and replied to some of the open questions. I am eager to see your feedback on them!

Again, thanks for the support here!

[rafaelweingartner]

Thanks @chungg! Your support is much appreciated!

[rafaelweingartner]

@chungg the error is caused by a numpy upgrade. I cheated a patch to address it via: https://github.com/gnocchixyz/gnocchi/pull/1390. After that is merged, I can rebase this one here.

[rafaelweingartner]

@chungg now this patch seems to be fine. I also squashed all commits to avoid mixing up things, as the patch was depending on others.

[rafaelweingartner]

Thank you guys (@pedro-martins and @chungg) for your reviews!

If you think that there is something else to be changed, let me know.

[rafaelweingartner]

lgtm

Thanks!

As soon as this one is merged, I will rebase https://github.com/gnocchixyz/gnocchi/pull/1386, and make it ready for review as well.

Then, we will be able to implement a solution for https://github.com/gnocchixyz/gnocchi/issues/1182.

[rafaelweingartner]

Hello @chungg and @tobias-urdin can we merge this one. I have some time this week, and I would like to use this time to rebase the other patch as soon as this patch is merged.

[rafaelweingartner]

Thanks!