Cabbage general alerting review and migration to mimir

[QuentinBisson]

Towards https://github.com/giantswarm/roadmap/issues/3312

Atlas is planning to migrate our monitoring setup to mimir targetting CAPI only. This will result in all data being in a single database, instead of the current one-prometheus-per-cluster setup. Current alerts have to be updated as queries will see all data for all clusters, MC and WC alike, instead of data for one specific cluster at a time.

We already did a lot of work towards this on the current alerts (removed a lot of deprecated alerts and providers, fixed alerts that clearly were not working an so on).

By doing so, we discovered a few things about Mimir itself but also that a chunk of our alert currently do not work on CAPI (e.g. based on vintage only components, deprecated and missing metrics an so on).

To ensure proper monitoring in CAPI and with Mimir, Atlas needs your help!

We would kindly ask all teams to help us out for the following use-cases, ordered in terms of priorities if they can't be performed all at once.

0. Create kickoff meetings for each teams

• [ ] Cabbage kick off meeting done - To be scheduled by atlas

1. Test and fix your teams alerts and dashboards on CAPI clusters.

A lot of the alerts we have do not work on CAPI (e.g. cluster-autoscaler, ebs-csi and external-dns) simply because they are flagged behind the "aws" provider only, or because they rely on metrics of vintage components (cluster_created|upgraded inhibitions). The specific alerts issue that were identified will be added to the team issues.

• [ ] Cabbage finished reviewing their alerts in prometheus-rules and sloth-rules on CAPI - please report it in the umbrella issue

2. Test and fix your teams alerts and dashboards on Mimir.

We currently have Mimir deployed on Golem for testing of alerts accessible as a datasource in grafana.

Current known/unknown with Mimir are behing written here by @giantswarm/team-atlas but feel free to add what you found.

We request a second round of testing for Mimir because Mimir in inherently different from our vintage monitoring setup. First,all metrics will be stored in one central place (we are not enabling multi-tenancy yet). This means that:

• No two alerts should have the same name
• All aggregations (sum, count, ...) must at the very least have cluster_id, provider and pipeline in the by clause
• All joins must at the very least have cluster_id, provider and pipeline in the on clause
• the promql absent function should be use carefully because this function renders an empty vector so having it empty for all clusters in a MC seems relatively impossible. If you target 1 cluster in particular, this could work (cluster_type="management_cluster" for example but we think it's best to rely on other mechanisms)

Second, for grafana cloud, we rely a lot on external labels (labels added by prometheus when metrics leave the cluster like installation, provider and so on) but data sent from mimir to grafana cloud will not have those external labels anymore so recording rules aggregations and join must contain all eternal labels in the on and by clauses (that was mostly done by atlas but please review)

Third, we know that the alerting link (prometheus query) in opsgenie and slack will not work directly because Mimir does not have a UI per se (hint: it's grafana). The only way to have this source link back is to migrate to mimir's alertmanager but that's a whole over beast that we cannot tacke right now so we advise you, for each alert, to try to find a dashboard can be linked to the alert to help with oncall.

• [ ] Cabbage finished reviewing their alerts in prometheus-rules and sloth-rules and dashboards on Mimir - please report it in the umbrella issue

3. Move away from the old slo framework towards sloth

We deprecated the old slo dashboard a while ago in favor of sloth but teams are not really using it. We would love if you could replace the old slo alerts with sloth-based ones.

• [ ] Cabbage migrated away from the old slo framework using sloth (tested in both CAPI and Mimir) - please report it in the umbrella issue

4. Test Grafana Cloud dashboards with golem data

As mimir data will be sent to grafana cloud by a single prometheus with no external labels, we would like you to ensure the grafana cloud dashboard that your team owns work on golem.

This is currently blocked by https://github.com/giantswarm/roadmap/issues/3159

• [ ] Cabbage fixed their grafana cloud dashboards - please report it in the umbrella issue

5. Move all apps (latest versions) to service monitors

Towards closing this https://github.com/giantswarm/giantswarm/issues/27145

There are still some leftovers (although not a lot) that still need to use a service monitor. Without this, we will not be able to tear down our Prometheus stack.

This is not that much of a priority but the effort should be rather small and easy to finish so feel free to pick this up

To easily find out what is not monitored via service monitors, you can connect to a MC and WC prometheus using opsctl open -i -a prometheus --workload-cluster= and check out the targets page. If they are there (be careful to also check out the workload section), they need a servicemonitor :)

• [ ] Cabbage added their missing service monitors - please report it in the umbrella issue

We will of course be here to help you for the migration :)

Further info:

To help you, you can always add alert tests in prometheus-rules, those are great :)

[QuentinBisson]

@weatherhog coming from https://github.com/giantswarm/giantswarm/issues/29551

• external-dns is currently vintage aws only https://github.com/giantswarm/prometheus-rules/blob/4da1fd343f5e2c77f9ba6b91b57233634103320b/helm/prometheus-rules/templates/alerting-rules/external-dns.rules.yml#L1. Is it expected?

[mcharriere]

Also https://github.com/giantswarm/roadmap/issues/3293

[Rotfuks]

We've done the alert review which was the important part of this ticket. The rest is for now out of scope and we'll come around with follow up tickets once they have priority. I'll close this issue for now, thanks!