Merge pull request #18498 from ldufr/revive-emit-warning-when-sort-is-used-range

annotations: add warning for ineffective sort in range queries

promql/engine.go

@@ -2010,6 +2010,11 @@ func (ev *evaluator) eval(ctx context.Context, expr parser.Expr) (parser.Value,
 			return ev.evalInfo(ctx, e.Args)
 		}
 
+		// Emit a warning when sort is used for range queries.
+		if (e.Func.Name == "sort" || e.Func.Name == "sort_desc" || e.Func.Name == "sort_by_label" || e.Func.Name == "sort_by_label_desc") && ev.startTimestamp != ev.endTimestamp {
+			warnings.Add(annotations.NewSortInRangeQueryWarning(e.PositionRange()))
+		}
+
 		if !matrixArg {
 			// Does not have a matrix argument.
 			return ev.rangeEval(ctx, nil, func(v []Vector, _ Matrix, _ [][]EvalSeriesHelper, enh *EvalNodeHelper) (Vector, annotations.Annotations) {

promql/promqltest/testdata/histograms.test

@@ -1169,3 +1169,68 @@ eval instant at 0 histogram_fraction(-Inf, 1, series)
   expect no_info
   expect warn msg: PromQL warning: vector contains a mix of classic and native histograms for metric name "series"
   # Should return no results.
+
+clear
+
+# Test histogram_quantile(s) and histogram_fraction warns about missing "le"
+load 1m
+  series{ale="0.1"}   2
+
+eval instant at 0 histogram_quantile(0.8, series)
+	expect no_info
+	expect warn msg: PromQL warning: bucket label "le" is missing or has a malformed value of "" for metric name "series"
+	# Should return no results.
+
+eval instant at 0 histogram_quantiles(series, "q", 0.1, 0.2)
+	expect no_info
+	expect warn msg: PromQL warning: bucket label "le" is missing or has a malformed value of "" for metric name "series"
+	# Should return no results.
+
+eval instant at 0 histogram_fraction(-Inf, 1, series)
+	expect no_info
+	expect warn msg: PromQL warning: bucket label "le" is missing or has a malformed value of "" for metric name "series"
+	# Should return no results.
+
+clear
+
+# Test histogram_quantile(s) and histogram_fraction warns about malformated "le"
+load 1m
+  series{le="Hello World"}   2
+
+eval instant at 0 histogram_quantile(0.8, series)
+	expect no_info
+	expect warn msg: PromQL warning: bucket label "le" is missing or has a malformed value of "Hello World" for metric name "series"
+	# Should return no results.
+
+eval instant at 0 histogram_quantiles(series, "q", 0.1, 0.2)
+	expect no_info
+	expect warn msg: PromQL warning: bucket label "le" is missing or has a malformed value of "Hello World" for metric name "series"
+	# Should return no results.
+
+eval instant at 0 histogram_fraction(-Inf, 1, series)
+	expect no_info
+	expect warn msg: PromQL warning: bucket label "le" is missing or has a malformed value of "Hello World" for metric name "series"
+	# Should return no results.
+
+clear
+
+# Test histogram_quantile(s) and histogram_fraction warns about mixed classic and native histogram
+load 1m
+  series{le="0.1"}   1
+  series{le="1"}     2
+  series{}           {{schema:0 count:10 sum:50 buckets:[1 2 3]}}
+
+eval instant at 0 histogram_quantile(0.8, series)
+	expect no_info
+	expect warn msg: PromQL warning: vector contains a mix of classic and native histograms for metric name "series"
+	# Should return no results.
+
+eval instant at 0 histogram_quantiles(series, "q", 0.1, 0.2)
+	expect no_info
+	expect warn msg: PromQL warning: vector contains a mix of classic and native histograms for metric name "series"
+	# Should return no results.
+
+eval instant at 0 histogram_fraction(-Inf, 1, series)
+	expect no_info
+	expect warn msg: PromQL warning: vector contains a mix of classic and native histograms for metric name "series"
+	# Should return no results.

promql/promqltest/testdata/range_queries.test

@@ -104,4 +104,19 @@ eval instant at 1m some_nonexistent_metric[1m]
     expect range vector from 10s to 1m step 10s
 
 eval instant at 10m some_metric[1m]
-    expect range vector from 9m10s to 10m step 1m
+    expect range vector from 9m10s to 10m step 1m
+
+eval range from 1m to 2m step 1m sort(series)
+  expect warn msg: PromQL warning: sort is ineffective for range queries since results are always ordered by labels
+
+eval range from 1m to 2m step 1m sort_desc(series)
+  expect warn msg: PromQL warning: sort is ineffective for range queries since results are always ordered by labels
+
+eval range from 1m to 2m step 1m sort_by_label(series)
+  expect warn msg: PromQL warning: sort is ineffective for range queries since results are always ordered by labels
+
+eval range from 1m to 2m step 1m sort_by_label_desc(series)
+  expect warn msg: PromQL warning: sort is ineffective for range queries since results are always ordered by labels
+
+eval range from 1m to 2m step 1m sum(sort(series))
+  expect warn msg: PromQL warning: sort is ineffective for range queries since results are always ordered by labels

util/annotations/annotations.go

@@ -156,6 +156,7 @@ var (
 	NativeHistogramNotGaugeWarning          = fmt.Errorf("%w: this native histogram metric is not a gauge:", PromQLWarning)
 	MixedExponentialCustomHistogramsWarning = fmt.Errorf("%w: vector contains a mix of histograms with exponential and custom buckets schemas for metric name", PromQLWarning)
 	IncompatibleBucketLayoutInBinOpWarning  = fmt.Errorf("%w: incompatible bucket layout encountered for binary operator", PromQLWarning)
+	SortInRangeQueryWarning                 = fmt.Errorf("%w: sort is ineffective for range queries since results are always ordered by labels", PromQLWarning)
 
 	PossibleNonCounterInfo                  = fmt.Errorf("%w: metric might not be a counter, name does not end in _total/_sum/_count/_bucket:", PromQLInfo)
 	PossibleNonCounterLabelInfo             = fmt.Errorf("%w: metric might not be a counter, __type__ label is not set to %q or %q", PromQLInfo, model.MetricTypeCounter, model.MetricTypeHistogram)
@@ -424,6 +425,15 @@ func NewIncompatibleBucketLayoutInBinOpWarning(operator string, pos posrange.Pos
 	}
 }
 
+// NewSortInRangeQueryWarning is used when sort or sort_desc functions are used
+// in range queries where they have no effect since results are always ordered by labels.
+func NewSortInRangeQueryWarning(pos posrange.PositionRange) error {
+	return &annoErr{
+		PositionRange: pos,
+		Err:           SortInRangeQueryWarning,
+	}
+}
+
 func NewNativeHistogramQuantileNaNResultInfo(metricName string, pos posrange.PositionRange) error {
 	return &annoErr{
 		PositionRange: pos,