Apply suggestions from code review

Co-authored-by: gotjosh <[email protected]>

CHANGELOG.md

@@ -8,12 +8,12 @@
 * [CHANGE] Querier: pass query matchers to queryable `IsApplicable` hook. #10256
 * [ENHANCEMENT] Distributor: OTLP receiver now converts also metric metadata. See also https://github.com/prometheus/prometheus/pull/15416. #10168
 * [ENHANCEMENT] Distributor: discard float and histogram samples with duplicated timestamps from each timeseries in a request before the request is forwarded to ingesters. Discarded samples are tracked by the `cortex_discarded_samples_total` metrics with reason `sample_duplicate_timestamp`. #10145
-* [CHANGE] Ruler: Add `cortex_prometheus_rule_group_last_rule_duration_sum_seconds` metric to track the total evalation duration of a rule group regardless of concurrency #10189
+* [ENHANCEMENT] Ruler: Add `cortex_prometheus_rule_group_last_rule_duration_sum_seconds` metric to track the total evalation duration of a rule group regardless of concurrency #10189
 * [BUGFIX] Distributor: Use a boolean to track changes while merging the ReplicaDesc components, rather than comparing the objects directly. #10185
 * [BUGFIX] Querier: fix timeout responding to query-frontend when response size is very close to `-querier.frontend-client.grpc-max-send-msg-size`. #10154
 * [BUGFIX] Ruler: fix indeterminate rules being always run concurrently (instead of never) when `-ruler.max-independent-rule-evaluation-concurrency` is set. https://github.com/prometheus/prometheus/pull/15560 #10258
 * [BUGFIX] PromQL: Fix various UTF-8 bugs related to quoting. https://github.com/prometheus/prometheus/pull/15531 #10258
-* [BUGFIX] Ruler: Prevent flapping (enabled/disabled) of the concurrency feature #10189
+* [BUGFIX] Ruler: Fixed an issue when using the experimental `-ruler.max-independent-rule-evaluation-concurrency` feature, where if a rule group was eligible for concurrency, it would flap between running concurrently or not based on the time it took after running concurrently. #9726 #10189
 
 ### Mixin
 

pkg/ruler/manager_metrics.go

@@ -164,7 +164,7 @@ func (m *ManagerMetrics) Collect(out chan<- prometheus.Metric) {
 	data.SendSumOfGaugesPerTenant(out, m.GroupInterval, "prometheus_rule_group_interval_seconds", dskit_metrics.WithLabels("rule_group"))
 	data.SendSumOfGaugesPerTenant(out, m.GroupLastEvalTime, "prometheus_rule_group_last_evaluation_timestamp_seconds", dskit_metrics.WithLabels("rule_group"))
 	data.SendSumOfGaugesPerTenant(out, m.GroupLastDuration, "prometheus_rule_group_last_duration_seconds", dskit_metrics.WithLabels("rule_group"))
-	data.SendSumOfGaugesPerTenant(out, m.GroupLastRuleDurationSum, "cortex_prometheus_rule_group_last_rule_duration_sum_seconds", dskit_metrics.WithLabels("rule_group"))
+	data.SendSumOfGaugesPerTenant(out, m.GroupLastRuleDurationSum, "prometheus_rule_group_last_rule_duration_sum_seconds", dskit_metrics.WithLabels("rule_group"))
 	data.SendSumOfGaugesPerTenant(out, m.GroupRules, "prometheus_rule_group_rules", dskit_metrics.WithLabels("rule_group"))
 	data.SendSumOfGaugesPerTenant(out, m.GroupLastEvalSamples, "prometheus_rule_group_last_evaluation_samples", dskit_metrics.WithLabels("rule_group"))
 }