Sloth uses Prometheus rules to generate SLOs (Service Level Objectives). Based on the generated recording and alert rules it creates a reliable and uniform SLO implementation:
The Prometheus rules that Sloth generates, fall in 3 categories:
- SLIs: These rules are the base, they use the queries provided by the user to get a value used to show what is the error service level (availability). It creates multiple rules for different time windows, these different results will be used for the alerts.
- Metadata: These are used as informative metrics, like the remaining error budget, the SLO objective percent, etc. These are very handy for SLO visualization, e.g. Grafana dashboard.
- Alerts: These are the multi-window/multi-burn alerts that are based on the SLI rules.
Sloth will take the service level spec and for each SLO in the spec will create 3 rule groups with the above categories.