MQE: fix panic in rate or increase over native histograms with ch…

…anging schema (#9518) (#9522) * MQE: fix panic in `rate` or `increase` over native histograms with changing schema * Add changelog entry * Add test for `increase` too (cherry picked from commit caa2fb9) # Conflicts: # CHANGELOG.md
grafana · Oct 4, 2024 · ce7c972 · ce7c972
1 parent 69f4788
commit ce7c972
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Showing 3 changed files with 15 additions and 6 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -33,7 +33,7 @@
 * [CHANGE] Query-scheduler: Remove the experimental `-query-scheduler.use-multi-algorithm-query-queue` flag. The new multi-algorithm tree queue is always used for the scheduler. #9210
 * [FEATURE] Alertmanager: Added `-alertmanager.log-parsing-label-matchers` to control logging when parsing label matchers. This flag is intended to be used with `-alertmanager.utf8-strict-mode-enabled` to validate UTF-8 strict mode is working as intended. The default value is `false`. #9173
 * [FEATURE] Alertmanager: Added `-alertmanager.utf8-migration-logging-enabled` to enable logging of tenant configurations that are incompatible with UTF-8 strict mode. The default value is `false`. #9174
-* [FEATURE] Querier: add experimental streaming PromQL engine, enabled with `-querier.query-engine=mimir`. #8422 #8430 #8454 #8455 #8360 #8490 #8508 #8577 #8660 #8671 #8677 #8747 #8850 #8872 #8838 #8911 #8909 #8923 #8924 #8925 #8932 #8933 #8934 #8962 #8986 #8993 #8995 #9008 #9017 #9018 #9019 #9120 #9121 #9136 #9139 #9140 #9145 #9191 #9192 #9194 #9196 #9201 #9212 #9225 #9260 #9272 #9277 #9278 #9280 #9371 #9482
+* [FEATURE] Querier: add experimental streaming PromQL engine, enabled with `-querier.query-engine=mimir`. #8422 #8430 #8454 #8455 #8360 #8490 #8508 #8577 #8660 #8671 #8677 #8747 #8850 #8872 #8838 #8911 #8909 #8923 #8924 #8925 #8932 #8933 #8934 #8962 #8986 #8993 #8995 #9008 #9017 #9018 #9019 #9120 #9121 #9136 #9139 #9140 #9145 #9191 #9192 #9194 #9196 #9201 #9212 #9225 #9260 #9272 #9277 #9278 #9280 #9371 #9482 #9518
 * [FEATURE] Experimental Kafka-based ingest storage. #6888 #6894 #6929 #6940 #6951 #6974 #6982 #7029 #7030 #7091 #7142 #7147 #7148 #7153 #7160 #7193 #7349 #7376 #7388 #7391 #7393 #7394 #7402 #7404 #7423 #7424 #7437 #7486 #7503 #7508 #7540 #7621 #7682 #7685 #7694 #7695 #7696 #7697 #7701 #7733 #7734 #7741 #7752 #7838 #7851 #7871 #7877 #7880 #7882 #7887 #7891 #7925 #7955 #7967 #8031 #8063 #8077 #8088 #8135 #8176 #8184 #8194 #8216 #8217 #8222 #8233 #8503 #8542 #8579 #8657 #8686 #8688 #8703 #8706 #8708 #8738 #8750 #8778 #8808 #8809 #8841 #8842 #8845 #8853 #8886 #8988
   * What it is:
     * When the new ingest storage architecture is enabled, distributors write incoming write requests to a Kafka-compatible backend, and the ingesters asynchronously replay ingested data from Kafka. In this architecture, the write and read path are de-coupled through a Kafka-compatible backend. The write path and Kafka load is a function of the incoming write traffic, the read path load is a function of received queries. Whatever the load on the read path, it doesn't affect the write path.

diff --git a/pkg/streamingpromql/functions/rate.go b/pkg/streamingpromql/functions/rate.go
@@ -74,17 +74,17 @@ func histogramRate(step types.RangeVectorStepData, hHead []promql.HPoint, hTail
 		emitAnnotation(annotations.NewNativeHistogramNotCounterWarning)
 	}
 
-	currentSchema := firstPoint.H.Schema
-	if lastPoint.H.Schema < currentSchema {
-		currentSchema = lastPoint.H.Schema
+	initialSchema := firstPoint.H.Schema
+	if lastPoint.H.Schema < initialSchema {
+		initialSchema = lastPoint.H.Schema
 	}
 
 	usingCustomBuckets := firstPoint.H.UsesCustomBuckets()
 	if lastPoint.H.UsesCustomBuckets() != usingCustomBuckets {
 		return nil, histogram.ErrHistogramsIncompatibleSchema
 	}
 
-	delta := lastPoint.H.CopyToSchema(currentSchema)
+	delta := lastPoint.H.CopyToSchema(initialSchema)
 	_, err := delta.Sub(firstPoint.H)
 	if err != nil {
 		return nil, err
@@ -104,7 +104,7 @@ func histogramRate(step types.RangeVectorStepData, hHead []promql.HPoint, hTail
 				return histogram.ErrHistogramsIncompatibleSchema
 			}
 
-			if p.H.Schema < currentSchema {
+			if p.H.Schema < delta.Schema {
 				delta = delta.CopyToSchema(p.H.Schema)
 			}
 

diff --git a/pkg/streamingpromql/testdata/ours/native_histograms.test b/pkg/streamingpromql/testdata/ours/native_histograms.test
@@ -185,3 +185,12 @@ load 6m
 # T=18: compatible
 eval_warn range from 0 to 18m step 6m sum(metric)
   {} _ {{schema:-53 sum:2 count:2 custom_values:[5 10] buckets:[2 4]}} _ {{schema:-53 sum:3.8 count:6 custom_values:[3] buckets:[6]}}
+
+clear
+
+# Test rate() and increase() over native histograms with changing schemas.
+load 1m
+  metric {{schema:4 sum:2 count:2 buckets:[2]}} {{schema:2 sum:6 count:12 buckets:[12]}} {{schema:3 sum:12 count:24 buckets:[24]}} {{schema:4 sum:164 count:326 buckets:[326]}}
+
+eval instant at 3m rate(metric[3m])
+  {} {{schema:2 sum:1 count:2 buckets:[2] counter_reset_hint:gauge}}