lib/storage: properly handle queries containing a filter on metric name plus any number of negative filters and zero non-negative filters

Example: `node_cpu_seconds_total{mode!="idle"}`

docs/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 # tip
 
+* BUGFIX: properly handle queries containing a filter on metric name plus any number of negative filters and zero non-negative filters. For example, `node_cpu_seconds_total{mode!="idle"}`. The bug was introduced in [v1.54.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.54.0).
+
 
 # [v1.54.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.54.0)
 

lib/storage/tag_filters.go

@@ -36,13 +36,16 @@ func convertToCompositeTagFilters(tfs *TagFilters) *TagFilters {
 		}
 	}
 	if len(name) == 0 {
-		// There is no metric name filter, so composite filters cannot be created.
+		// Composite filters cannot be created in the following cases:
+		// - if there is no filter on metric name
+		// - if there is no at least a single positive filter.
 		atomic.AddUint64(&compositeFilterMissingConversions, 1)
 		return tfs
 	}
 	tfsNew := make([]tagFilter, 0, len(tfs.tfs))
 	var compositeKey []byte
 	compositeFilters := 0
+	hasPositiveFilter := false
 	for _, tf := range tfs.tfs {
 		if len(tf.key) == 0 {
 			if tf.isNegative || tf.isRegexp || string(tf.value) != string(name) {
@@ -59,10 +62,13 @@ func convertToCompositeTagFilters(tfs *TagFilters) *TagFilters {
 		if err := tfNew.Init(tfs.commonPrefix, compositeKey, tf.value, tf.isNegative, tf.isRegexp); err != nil {
 			logger.Panicf("BUG: unexpected error when creating composite tag filter for name=%q and key=%q: %s", name, tf.key, err)
 		}
+		if !tfNew.isNegative {
+			hasPositiveFilter = true
+		}
 		tfsNew = append(tfsNew, tfNew)
 		compositeFilters++
 	}
-	if compositeFilters == 0 {
+	if compositeFilters == 0 || !hasPositiveFilter {
 		atomic.AddUint64(&compositeFilterMissingConversions, 1)
 		return tfs
 	}

lib/storage/tag_filters_test.go

@@ -156,6 +156,70 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		},
 	})
 
+	// A name filter with a single negative filter
+	f([]TagFilter{
+		{
+			Key:        nil,
+			Value:      []byte("bar"),
+			IsNegative: false,
+			IsRegexp:   false,
+		},
+		{
+			Key:        []byte("foo"),
+			Value:      []byte("abc"),
+			IsNegative: true,
+			IsRegexp:   false,
+		},
+	}, []TagFilter{
+		{
+			Key:        nil,
+			Value:      []byte("bar"),
+			IsNegative: false,
+			IsRegexp:   false,
+		},
+		{
+			Key:        []byte("foo"),
+			Value:      []byte("abc"),
+			IsNegative: true,
+			IsRegexp:   false,
+		},
+	})
+
+	// A name filter with a negative and a positive filter
+	f([]TagFilter{
+		{
+			Key:        nil,
+			Value:      []byte("bar"),
+			IsNegative: false,
+			IsRegexp:   false,
+		},
+		{
+			Key:        []byte("foo"),
+			Value:      []byte("abc"),
+			IsNegative: true,
+			IsRegexp:   false,
+		},
+		{
+			Key:        []byte("a"),
+			Value:      []byte("b.+"),
+			IsNegative: false,
+			IsRegexp:   true,
+		},
+	}, []TagFilter{
+		{
+			Key:        []byte("\xfe\x03barfoo"),
+			Value:      []byte("abc"),
+			IsNegative: true,
+			IsRegexp:   false,
+		},
+		{
+			Key:        []byte("\xfe\x03bara"),
+			Value:      []byte("b.+"),
+			IsNegative: false,
+			IsRegexp:   true,
+		},
+	})
+
 	// Two name filters with non-name filter.
 	f([]TagFilter{
 		{
@@ -191,7 +255,7 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		},
 	})
 
-	// A name filter with negative regexp non-name filter, which can be converted to non-regexp.
+	// A name filter with regexp non-name filter, which can be converted to non-regexp.
 	f([]TagFilter{
 		{
 			Key:        nil,
@@ -202,19 +266,19 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		{
 			Key:        []byte("foo"),
 			Value:      []byte("abc"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   true,
 		},
 	}, []TagFilter{
 		{
 			Key:        []byte("\xfe\x03barfoo"),
 			Value:      []byte("abc"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   false,
 		},
 	})
 
-	// A name filter with negative regexp non-name filter.
+	// A name filter with regexp non-name filter.
 	f([]TagFilter{
 		{
 			Key:        nil,
@@ -225,14 +289,14 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		{
 			Key:        []byte("foo"),
 			Value:      []byte("abc.+"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   true,
 		},
 	}, []TagFilter{
 		{
 			Key:        []byte("\xfe\x03barfoo"),
 			Value:      []byte("abc.+"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   true,
 		},
 	})
@@ -277,7 +341,7 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		{
 			Key:        []byte("foo"),
 			Value:      []byte("abc"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   true,
 		},
 		{
@@ -290,7 +354,7 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		{
 			Key:        []byte("\xfe\x03barfoo"),
 			Value:      []byte("abc"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   false,
 		},
 		{
@@ -312,14 +376,14 @@ func TestConvertToCompositeTagFilters(t *testing.T) {
 		{
 			Key:        []byte("foo"),
 			Value:      []byte("abc"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   false,
 		},
 	}, []TagFilter{
 		{
 			Key:        []byte("\xfe\x03barfoo"),
 			Value:      []byte("abc"),
-			IsNegative: true,
+			IsNegative: false,
 			IsRegexp:   false,
 		},
 	})