[release-12.2.2] docs(alerting): add additional migration details (#113165)

docs(alerting): add additional migration details (#112383)

(cherry picked from commit 86bf99aaaa)

Co-authored-by: Pepe Cano <825430+ppcano@users.noreply.github.com>
This commit is contained in:
grafana-delivery-bot[bot]
2025-10-29 13:14:25 +00:00
committed by GitHub
co-authored by Pepe Cano
parent f639587fc9
commit c3460a4038
@@ -65,6 +65,10 @@ The copied rules are converted to Grafana-managed rules, preserving their behavi
The rule query offset is taken from the `query_offset` value in the rule group configuration. If empty, it defaults to the [`rule_query_offset` configuration setting](ref:configure-grafana-rule_query_offset), which is `1m` by default.
- **Rule query conversion**
For alert rules, adds `prometheus_math` and `threshold` expressions to preserve Prometheus no data behavior, ensuring the alert stays in **Normal** state when `query` returns no data.
- **Missing series evaluations to resolve**
The [Missing series evaluations to resolve](ref:missing_series_evaluations_to_resolve) setting is set to `1` to replicate Prometheus’s alert eviction behavior.