Merge branch 'main' into nhcb

CONTRIBUTING.md

@@ -90,7 +90,7 @@ can modify the `./promql/parser/generated_parser.y.go` manually.
 ```golang
 // As of writing this was somewhere around line 600.
 var (
-	yyDebug        = 0 // This can be be a number 0 -> 5.
+	yyDebug        = 0 // This can be a number 0 -> 5.
 	yyErrorVerbose = false  // This can be set to true.
 )
 

cmd/promtool/tsdb.go

@@ -33,6 +33,7 @@ import (
 
 	"github.com/alecthomas/units"
 	"github.com/go-kit/log"
+	"go.uber.org/atomic"
 
 	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/promql/parser"
@@ -149,8 +150,7 @@ func benchmarkWrite(outPath, samplesFile string, numMetrics, numScrapes int) err
 }
 
 func (b *writeBenchmark) ingestScrapes(lbls []labels.Labels, scrapeCount int) (uint64, error) {
-	var mu sync.Mutex
-	var total uint64
+	var total atomic.Uint64
 
 	for i := 0; i < scrapeCount; i += 100 {
 		var wg sync.WaitGroup
@@ -165,22 +165,21 @@ func (b *writeBenchmark) ingestScrapes(lbls []labels.Labels, scrapeCount int) (u
 
 			wg.Add(1)
 			go func() {
+				defer wg.Done()
+
 				n, err := b.ingestScrapesShard(batch, 100, int64(timeDelta*i))
 				if err != nil {
 					// exitWithError(err)
 					fmt.Println(" err", err)
 				}
-				mu.Lock()
-				total += n
-				mu.Unlock()
-				wg.Done()
+				total.Add(n)
 			}()
 		}
 		wg.Wait()
 	}
 	fmt.Println("ingestion completed")
 
-	return total, nil
+	return total.Load(), nil
 }
 
 func (b *writeBenchmark) ingestScrapesShard(lbls []labels.Labels, scrapeCount int, baset int64) (uint64, error) {

cmd/promtool/unittest.go

@@ -175,13 +175,18 @@ type testGroup struct {
 }
 
 // test performs the unit tests.
-func (tg *testGroup) test(evalInterval time.Duration, groupOrderMap map[string]int, queryOpts promql.LazyLoaderOpts, diffFlag bool, ruleFiles ...string) []error {
+func (tg *testGroup) test(evalInterval time.Duration, groupOrderMap map[string]int, queryOpts promql.LazyLoaderOpts, diffFlag bool, ruleFiles ...string) (outErr []error) {
 	// Setup testing suite.
-	suite, err := promql.NewLazyLoader(nil, tg.seriesLoadingString(), queryOpts)
+	suite, err := promql.NewLazyLoader(tg.seriesLoadingString(), queryOpts)
 	if err != nil {
 		return []error{err}
 	}
-	defer suite.Close()
+	defer func() {
+		err := suite.Close()
+		if err != nil {
+			outErr = append(outErr, err)
+		}
+	}()
 	suite.SubqueryInterval = evalInterval
 
 	// Load the rule files.

discovery/azure/azure.go

@@ -213,6 +213,14 @@ func NewDiscovery(cfg *SDConfig, logger log.Logger, metrics discovery.Discoverer
 	return d, nil
 }
 
+type client interface {
+	getVMs(ctx context.Context, resourceGroup string) ([]virtualMachine, error)
+	getScaleSets(ctx context.Context, resourceGroup string) ([]armcompute.VirtualMachineScaleSet, error)
+	getScaleSetVMs(ctx context.Context, scaleSet armcompute.VirtualMachineScaleSet) ([]virtualMachine, error)
+	getVMNetworkInterfaceByID(ctx context.Context, networkInterfaceID string) (*armnetwork.Interface, error)
+	getVMScaleSetVMNetworkInterfaceByID(ctx context.Context, networkInterfaceID, scaleSetName, instanceID string) (*armnetwork.Interface, error)
+}
+
 // azureClient represents multiple Azure Resource Manager providers.
 type azureClient struct {
 	nic    *armnetwork.InterfacesClient
@@ -222,14 +230,17 @@ type azureClient struct {
 	logger log.Logger
 }
 
+var _ client = &azureClient{}
+
 // createAzureClient is a helper function for creating an Azure compute client to ARM.
-func createAzureClient(cfg SDConfig) (azureClient, error) {
+func createAzureClient(cfg SDConfig, logger log.Logger) (client, error) {
 	cloudConfiguration, err := CloudConfigurationFromName(cfg.Environment)
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 
 	var c azureClient
+	c.logger = logger
 
 	telemetry := policy.TelemetryOptions{
 		ApplicationID: userAgent,
@@ -240,12 +251,12 @@ func createAzureClient(cfg SDConfig) (azureClient, error) {
 		Telemetry: telemetry,
 	})
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 
 	client, err := config_util.NewClientFromConfig(cfg.HTTPClientConfig, "azure_sd")
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 	options := &arm.ClientOptions{
 		ClientOptions: policy.ClientOptions{
@@ -257,25 +268,25 @@ func createAzureClient(cfg SDConfig) (azureClient, error) {
 
 	c.vm, err = armcompute.NewVirtualMachinesClient(cfg.SubscriptionID, credential, options)
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 
 	c.nic, err = armnetwork.NewInterfacesClient(cfg.SubscriptionID, credential, options)
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 
 	c.vmss, err = armcompute.NewVirtualMachineScaleSetsClient(cfg.SubscriptionID, credential, options)
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 
 	c.vmssvm, err = armcompute.NewVirtualMachineScaleSetVMsClient(cfg.SubscriptionID, credential, options)
 	if err != nil {
-		return azureClient{}, err
+		return &azureClient{}, err
 	}
 
-	return c, nil
+	return &c, nil
 }
 
 func newCredential(cfg SDConfig, policyClientOptions policy.ClientOptions) (azcore.TokenCredential, error) {
@@ -341,12 +352,11 @@ func newAzureResourceFromID(id string, logger log.Logger) (*arm.ResourceID, erro
 func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 	defer level.Debug(d.logger).Log("msg", "Azure discovery completed")
 
-	client, err := createAzureClient(*d.cfg)
+	client, err := createAzureClient(*d.cfg, d.logger)
 	if err != nil {
 		d.metrics.failuresCount.Inc()
 		return nil, fmt.Errorf("could not create Azure client: %w", err)
 	}
-	client.logger = d.logger
 
 	machines, err := client.getVMs(ctx, d.cfg.ResourceGroup)
 	if err != nil {
@@ -385,10 +395,32 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 	for _, vm := range machines {
 		go func(vm virtualMachine) {
 			defer wg.Done()
+			labelSet, err := d.vmToLabelSet(ctx, client, vm)
+			ch <- target{labelSet: labelSet, err: err}
+		}(vm)
+	}
+
+	wg.Wait()
+	close(ch)
+
+	var tg targetgroup.Group
+	for tgt := range ch {
+		if tgt.err != nil {
+			d.metrics.failuresCount.Inc()
+			return nil, fmt.Errorf("unable to complete Azure service discovery: %w", tgt.err)
+		}
+		if tgt.labelSet != nil {
+			tg.Targets = append(tg.Targets, tgt.labelSet)
+		}
+	}
+
+	return []*targetgroup.Group{&tg}, nil
+}
+
+func (d *Discovery) vmToLabelSet(ctx context.Context, client client, vm virtualMachine) (model.LabelSet, error) {
 	r, err := newAzureResourceFromID(vm.ID, d.logger)
 	if err != nil {
-				ch <- target{labelSet: nil, err: err}
-				return
+		return nil, err
 	}
 
 	labels := model.LabelSet{
@@ -424,16 +456,14 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 			} else {
 				networkInterface, err = client.getVMScaleSetVMNetworkInterfaceByID(ctx, nicID, vm.ScaleSet, vm.InstanceID)
 			}
-
 			if err != nil {
 				if errors.Is(err, errorNotFound) {
 					level.Warn(d.logger).Log("msg", "Network interface does not exist", "name", nicID, "err", err)
 				} else {
-							ch <- target{labelSet: nil, err: err}
+					return nil, err
 				}
-
 				// Get out of this routine because we cannot continue without a network interface.
-						return
+				return nil, nil
 			}
 
 			// Continue processing with the network interface
@@ -450,7 +480,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 		// is a cheap and easy way to determine if a machine is allocated or not.
 		if networkInterface.Properties.Primary == nil {
 			level.Debug(d.logger).Log("msg", "Skipping deallocated virtual machine", "machine", vm.Name)
-					return
+			return nil, nil
 		}
 
 		if *networkInterface.Properties.Primary {
@@ -464,35 +494,16 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 					labels[azureLabelMachinePrivateIP] = model.LabelValue(*ip.Properties.PrivateIPAddress)
 					address := net.JoinHostPort(*ip.Properties.PrivateIPAddress, fmt.Sprintf("%d", d.port))
 					labels[model.AddressLabel] = model.LabelValue(address)
-							ch <- target{labelSet: labels, err: nil}
-							return
+					return labels, nil
 				}
 				// If we made it here, we don't have a private IP which should be impossible.
 				// Return an empty target and error to ensure an all or nothing situation.
-						err = fmt.Errorf("unable to find a private IP for VM %s", vm.Name)
-						ch <- target{labelSet: nil, err: err}
-						return
+				return nil, fmt.Errorf("unable to find a private IP for VM %s", vm.Name)
 			}
 		}
 	}
-		}(vm)
-	}
-
-	wg.Wait()
-	close(ch)
-
-	var tg targetgroup.Group
-	for tgt := range ch {
-		if tgt.err != nil {
-			d.metrics.failuresCount.Inc()
-			return nil, fmt.Errorf("unable to complete Azure service discovery: %w", tgt.err)
-		}
-		if tgt.labelSet != nil {
-			tg.Targets = append(tg.Targets, tgt.labelSet)
-		}
-	}
-
-	return []*targetgroup.Group{&tg}, nil
+	// TODO: Should we say something at this point?
+	return nil, nil
 }
 
 func (client *azureClient) getVMs(ctx context.Context, resourceGroup string) ([]virtualMachine, error) {

discovery/azure/azure_test.go

@@ -14,16 +14,24 @@
 package azure
 
 import (
+	"context"
+	"fmt"
 	"testing"
 
 	"github.com/Azure/azure-sdk-for-go/sdk/azcore/arm"
 	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/compute/armcompute/v5"
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/network/armnetwork/v4"
+	cache "github.com/Code-Hex/go-generics-cache"
+	"github.com/Code-Hex/go-generics-cache/policy/lru"
+	"github.com/go-kit/log"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/goleak"
 )
 
 func TestMain(m *testing.M) {
-	goleak.VerifyTestMain(m)
+	goleak.VerifyTestMain(m,
+		goleak.IgnoreTopFunction("github.com/Code-Hex/go-generics-cache.(*janitor).run.func1"),
+	)
 }
 
 func TestMapFromVMWithEmptyTags(t *testing.T) {
@@ -79,6 +87,91 @@ func TestMapFromVMWithEmptyTags(t *testing.T) {
 	require.Equal(t, expectedVM, actualVM)
 }
 
+func TestVMToLabelSet(t *testing.T) {
+	id := "/subscriptions/00000000-0000-0000-0000-000000000000/test"
+	name := "name"
+	size := "size"
+	vmSize := armcompute.VirtualMachineSizeTypes(size)
+	osType := armcompute.OperatingSystemTypesLinux
+	vmType := "type"
+	location := "westeurope"
+	computerName := "computer_name"
+	networkID := "/subscriptions/00000000-0000-0000-0000-000000000000/network1"
+	ipAddress := "10.20.30.40"
+	primary := true
+	networkProfile := armcompute.NetworkProfile{
+		NetworkInterfaces: []*armcompute.NetworkInterfaceReference{
+			{
+				ID:         &networkID,
+				Properties: &armcompute.NetworkInterfaceReferenceProperties{Primary: &primary},
+			},
+		},
+	}
+	properties := &armcompute.VirtualMachineProperties{
+		OSProfile: &armcompute.OSProfile{
+			ComputerName: &computerName,
+		},
+		StorageProfile: &armcompute.StorageProfile{
+			OSDisk: &armcompute.OSDisk{
+				OSType: &osType,
+			},
+		},
+		NetworkProfile: &networkProfile,
+		HardwareProfile: &armcompute.HardwareProfile{
+			VMSize: &vmSize,
+		},
+	}
+
+	testVM := armcompute.VirtualMachine{
+		ID:         &id,
+		Name:       &name,
+		Type:       &vmType,
+		Location:   &location,
+		Tags:       nil,
+		Properties: properties,
+	}
+
+	expectedVM := virtualMachine{
+		ID:                id,
+		Name:              name,
+		ComputerName:      computerName,
+		Type:              vmType,
+		Location:          location,
+		OsType:            "Linux",
+		Tags:              map[string]*string{},
+		NetworkInterfaces: []string{networkID},
+		Size:              size,
+	}
+
+	actualVM := mapFromVM(testVM)
+
+	require.Equal(t, expectedVM, actualVM)
+
+	cfg := DefaultSDConfig
+	d := &Discovery{
+		cfg:    &cfg,
+		logger: log.NewNopLogger(),
+		cache:  cache.New(cache.AsLRU[string, *armnetwork.Interface](lru.WithCapacity(5))),
+	}
+	network := armnetwork.Interface{
+		Name: &networkID,
+		Properties: &armnetwork.InterfacePropertiesFormat{
+			Primary: &primary,
+			IPConfigurations: []*armnetwork.InterfaceIPConfiguration{
+				{Properties: &armnetwork.InterfaceIPConfigurationPropertiesFormat{
+					PrivateIPAddress: &ipAddress,
+				}},
+			},
+		},
+	}
+	client := &mockAzureClient{
+		networkInterface: &network,
+	}
+	labelSet, err := d.vmToLabelSet(context.Background(), client, actualVM)
+	require.NoError(t, err)
+	require.Len(t, labelSet, 11)
+}
+
 func TestMapFromVMWithEmptyOSType(t *testing.T) {
 	id := "test"
 	name := "name"
@@ -381,3 +474,35 @@ func TestNewAzureResourceFromID(t *testing.T) {
 		require.Equal(t, tc.expected.ResourceGroupName, actual.ResourceGroupName)
 	}
 }
+
+type mockAzureClient struct {
+	networkInterface *armnetwork.Interface
+}
+
+var _ client = &mockAzureClient{}
+
+func (*mockAzureClient) getVMs(ctx context.Context, resourceGroup string) ([]virtualMachine, error) {
+	return nil, nil
+}
+
+func (*mockAzureClient) getScaleSets(ctx context.Context, resourceGroup string) ([]armcompute.VirtualMachineScaleSet, error) {
+	return nil, nil
+}
+
+func (*mockAzureClient) getScaleSetVMs(ctx context.Context, scaleSet armcompute.VirtualMachineScaleSet) ([]virtualMachine, error) {
+	return nil, nil
+}
+
+func (m *mockAzureClient) getVMNetworkInterfaceByID(ctx context.Context, networkInterfaceID string) (*armnetwork.Interface, error) {
+	if networkInterfaceID == "" {
+		return nil, fmt.Errorf("parameter networkInterfaceID cannot be empty")
+	}
+	return m.networkInterface, nil
+}
+
+func (m *mockAzureClient) getVMScaleSetVMNetworkInterfaceByID(ctx context.Context, networkInterfaceID, scaleSetName, instanceID string) (*armnetwork.Interface, error) {
+	if scaleSetName == "" {
+		return nil, fmt.Errorf("parameter virtualMachineScaleSetName cannot be empty")
+	}
+	return m.networkInterface, nil
+}

discovery/file/file_test.go

@@ -208,7 +208,6 @@ func (t *testRunner) requireUpdate(ref time.Time, expected []*targetgroup.Group)
 		select {
 		case <-timeout:
 			t.Fatalf("Expected update but got none")
-			return
 		case <-time.After(defaultWait / 10):
 			if ref.Equal(t.lastReceive()) {
 				// No update received.

discovery/legacymanager/manager_test.go

@@ -733,7 +733,6 @@ func verifyPresence(t *testing.T, tSets map[poolKey]map[string]*targetgroup.Grou
 	t.Helper()
 	if _, ok := tSets[poolKey]; !ok {
 		t.Fatalf("'%s' should be present in Pool keys: %v", poolKey, tSets)
-		return
 	}
 
 	match := false

discovery/manager_test.go

@@ -733,7 +733,6 @@ func verifySyncedPresence(t *testing.T, tGroups map[string][]*targetgroup.Group,
 	t.Helper()
 	if _, ok := tGroups[key]; !ok {
 		t.Fatalf("'%s' should be present in Group map keys: %v", key, tGroups)
-		return
 	}
 	match := false
 	var mergedTargets string

go.mod

@@ -74,7 +74,6 @@ require (
 	go.uber.org/automaxprocs v1.5.3
 	go.uber.org/goleak v1.3.0
 	go.uber.org/multierr v1.11.0
-	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a // indirect
 	golang.org/x/net v0.22.0
 	golang.org/x/oauth2 v0.18.0
 	golang.org/x/sync v0.6.0
@@ -186,6 +185,7 @@ require (
 	go.opentelemetry.io/otel/metric v1.24.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.1.0 // indirect
 	golang.org/x/crypto v0.21.0 // indirect
+	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a // indirect
 	golang.org/x/mod v0.16.0 // indirect
 	golang.org/x/term v0.18.0 // indirect
 	golang.org/x/text v0.14.0 // indirect

model/labels/labels.go

@@ -349,7 +349,9 @@ func (ls Labels) DropMetricName() Labels {
 			if i == 0 { // Make common case fast with no allocations.
 				return ls[1:]
 			}
-			return append(ls[:i], ls[i+1:]...)
+			// Avoid modifying original Labels - use [:i:i] so that left slice would not
+			// have any spare capacity and append would have to allocate a new slice for the result.
+			return append(ls[:i:i], ls[i+1:]...)
 		}
 	}
 	return ls

model/labels/labels_test.go

@@ -457,7 +457,11 @@ func TestLabels_Get(t *testing.T) {
 func TestLabels_DropMetricName(t *testing.T) {
 	require.True(t, Equal(FromStrings("aaa", "111", "bbb", "222"), FromStrings("aaa", "111", "bbb", "222").DropMetricName()))
 	require.True(t, Equal(FromStrings("aaa", "111"), FromStrings(MetricName, "myname", "aaa", "111").DropMetricName()))
-	require.True(t, Equal(FromStrings("__aaa__", "111", "bbb", "222"), FromStrings("__aaa__", "111", MetricName, "myname", "bbb", "222").DropMetricName()))
+
+	original := FromStrings("__aaa__", "111", MetricName, "myname", "bbb", "222")
+	check := FromStrings("__aaa__", "111", MetricName, "myname", "bbb", "222")
+	require.True(t, Equal(FromStrings("__aaa__", "111", "bbb", "222"), check.DropMetricName()))
+	require.True(t, Equal(original, check))
 }
 
 // BenchmarkLabels_Get was written to check whether a binary search can improve the performance vs the linear search implementation

model/labels/matcher.go

@@ -118,3 +118,30 @@ func (m *Matcher) GetRegexString() string {
 	}
 	return m.re.GetRegexString()
 }
+
+// SetMatches returns a set of equality matchers for the current regex matchers if possible.
+// For examples the regexp `a(b|f)` will returns "ab" and "af".
+// Returns nil if we can't replace the regexp by only equality matchers.
+func (m *Matcher) SetMatches() []string {
+	if m.re == nil {
+		return nil
+	}
+	return m.re.SetMatches()
+}
+
+// Prefix returns the required prefix of the value to match, if possible.
+// It will be empty if it's an equality matcher or if the prefix can't be determined.
+func (m *Matcher) Prefix() string {
+	if m.re == nil {
+		return ""
+	}
+	return m.re.prefix
+}
+
+// IsRegexOptimized returns whether regex is optimized.
+func (m *Matcher) IsRegexOptimized() bool {
+	if m.re == nil {
+		return false
+	}
+	return m.re.IsOptimized()
+}

model/labels/matcher_test.go

@@ -14,13 +14,14 @@
 package labels
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
 )
 
 func mustNewMatcher(t *testing.T, mType MatchType, value string) *Matcher {
-	m, err := NewMatcher(mType, "", value)
+	m, err := NewMatcher(mType, "test_label_name", value)
 	require.NoError(t, err)
 	return m
 }
@@ -81,6 +82,21 @@ func TestMatcher(t *testing.T) {
 			value:   "foo-bar",
 			match:   false,
 		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "$*bar"),
+			value:   "foo-bar",
+			match:   false,
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "bar^+"),
+			value:   "foo-bar",
+			match:   false,
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "$+bar"),
+			value:   "foo-bar",
+			match:   false,
+		},
 	}
 
 	for _, test := range tests {
@@ -118,6 +134,82 @@ func TestInverse(t *testing.T) {
 	}
 }
 
+func TestPrefix(t *testing.T) {
+	for i, tc := range []struct {
+		matcher *Matcher
+		prefix  string
+	}{
+		{
+			matcher: mustNewMatcher(t, MatchEqual, "abc"),
+			prefix:  "",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchNotEqual, "abc"),
+			prefix:  "",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "abc.+"),
+			prefix:  "abc",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "abcd|abc.+"),
+			prefix:  "abc",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchNotRegexp, "abcd|abc.+"),
+			prefix:  "abc",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "abc(def|ghj)|ab|a."),
+			prefix:  "a",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "foo.+bar|foo.*baz"),
+			prefix:  "foo",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "abc|.*"),
+			prefix:  "",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, "abc|def"),
+			prefix:  "",
+		},
+		{
+			matcher: mustNewMatcher(t, MatchRegexp, ".+def"),
+			prefix:  "",
+		},
+	} {
+		t.Run(fmt.Sprintf("%d: %s", i, tc.matcher), func(t *testing.T) {
+			require.Equal(t, tc.prefix, tc.matcher.Prefix())
+		})
+	}
+}
+
+func TestIsRegexOptimized(t *testing.T) {
+	for i, tc := range []struct {
+		matcher          *Matcher
+		isRegexOptimized bool
+	}{
+		{
+			matcher:          mustNewMatcher(t, MatchEqual, "abc"),
+			isRegexOptimized: false,
+		},
+		{
+			matcher:          mustNewMatcher(t, MatchRegexp, "."),
+			isRegexOptimized: false,
+		},
+		{
+			matcher:          mustNewMatcher(t, MatchRegexp, "abc.+"),
+			isRegexOptimized: true,
+		},
+	} {
+		t.Run(fmt.Sprintf("%d: %s", i, tc.matcher), func(t *testing.T) {
+			require.Equal(t, tc.isRegexOptimized, tc.matcher.IsRegexOptimized())
+		})
+	}
+}
+
 func BenchmarkMatchType_String(b *testing.B) {
 	for i := 0; i <= b.N; i++ {
 		_ = MatchType(i % int(MatchNotRegexp+1)).String()

model/labels/regexp.go

@@ -14,51 +14,90 @@
 package labels
 
 import (
+	"slices"
 	"strings"
 
 	"github.com/grafana/regexp"
 	"github.com/grafana/regexp/syntax"
 )
 
+const (
+	maxSetMatches = 256
+
+	// The minimum number of alternate values a regex should have to trigger
+	// the optimization done by optimizeEqualStringMatchers() and so use a map
+	// to match values instead of iterating over a list. This value has
+	// been computed running BenchmarkOptimizeEqualStringMatchers.
+	minEqualMultiStringMatcherMapThreshold = 16
+)
+
 type FastRegexMatcher struct {
+	// Under some conditions, re is nil because the expression is never parsed.
+	// We store the original string to be able to return it in GetRegexString().
+	reString string
 	re       *regexp.Regexp
+
+	setMatches    []string
+	stringMatcher StringMatcher
 	prefix        string
 	suffix        string
 	contains      string
 
-	// shortcut for literals
-	literal bool
-	value   string
+	// matchString is the "compiled" function to run by MatchString().
+	matchString func(string) bool
 }
 
 func NewFastRegexMatcher(v string) (*FastRegexMatcher, error) {
-	if isLiteral(v) {
-		return &FastRegexMatcher{literal: true, value: v}, nil
-	}
-	re, err := regexp.Compile("^(?:" + v + ")$")
-	if err != nil {
-		return nil, err
+	m := &FastRegexMatcher{
+		reString: v,
 	}
 
+	m.stringMatcher, m.setMatches = optimizeAlternatingLiterals(v)
+	if m.stringMatcher != nil {
+		// If we already have a string matcher, we don't need to parse the regex
+		// or compile the matchString function. This also avoids the behavior in
+		// compileMatchStringFunction where it prefers to use setMatches when
+		// available, even if the string matcher is faster.
+		m.matchString = m.stringMatcher.Matches
+	} else {
 		parsed, err := syntax.Parse(v, syntax.Perl)
 		if err != nil {
 			return nil, err
 		}
-
-	m := &FastRegexMatcher{
-		re: re,
+		// Simplify the syntax tree to run faster.
+		parsed = parsed.Simplify()
+		m.re, err = regexp.Compile("^(?:" + parsed.String() + ")$")
+		if err != nil {
+			return nil, err
 		}
-
 		if parsed.Op == syntax.OpConcat {
 			m.prefix, m.suffix, m.contains = optimizeConcatRegex(parsed)
 		}
+		if matches, caseSensitive := findSetMatches(parsed); caseSensitive {
+			m.setMatches = matches
+		}
+		m.stringMatcher = stringMatcherFromRegexp(parsed)
+		m.matchString = m.compileMatchStringFunction()
+	}
 
 	return m, nil
 }
 
-func (m *FastRegexMatcher) MatchString(s string) bool {
-	if m.literal {
-		return s == m.value
+// compileMatchStringFunction returns the function to run by MatchString().
+func (m *FastRegexMatcher) compileMatchStringFunction() func(string) bool {
+	// If the only optimization available is the string matcher, then we can just run it.
+	if len(m.setMatches) == 0 && m.prefix == "" && m.suffix == "" && m.contains == "" && m.stringMatcher != nil {
+		return m.stringMatcher.Matches
+	}
+
+	return func(s string) bool {
+		if len(m.setMatches) != 0 {
+			for _, match := range m.setMatches {
+				if match == s {
+					return true
+				}
+			}
+			return false
 		}
 		if m.prefix != "" && !strings.HasPrefix(s, m.prefix) {
 			return false
@@ -69,18 +108,254 @@ func (m *FastRegexMatcher) MatchString(s string) bool {
 		if m.contains != "" && !strings.Contains(s, m.contains) {
 			return false
 		}
+		if m.stringMatcher != nil {
+			return m.stringMatcher.Matches(s)
+		}
 		return m.re.MatchString(s)
 	}
+}
+
+// IsOptimized returns true if any fast-path optimization is applied to the
+// regex matcher.
+func (m *FastRegexMatcher) IsOptimized() bool {
+	return len(m.setMatches) > 0 || m.stringMatcher != nil || m.prefix != "" || m.suffix != "" || m.contains != ""
+}
+
+// findSetMatches extract equality matches from a regexp.
+// Returns nil if we can't replace the regexp by only equality matchers or the regexp contains
+// a mix of case sensitive and case insensitive matchers.
+func findSetMatches(re *syntax.Regexp) (matches []string, caseSensitive bool) {
+	clearBeginEndText(re)
+
+	return findSetMatchesInternal(re, "")
+}
+
+func findSetMatchesInternal(re *syntax.Regexp, base string) (matches []string, caseSensitive bool) {
+	switch re.Op {
+	case syntax.OpBeginText:
+		// Correctly handling the begin text operator inside a regex is tricky,
+		// so in this case we fallback to the regex engine.
+		return nil, false
+	case syntax.OpEndText:
+		// Correctly handling the end text operator inside a regex is tricky,
+		// so in this case we fallback to the regex engine.
+		return nil, false
+	case syntax.OpLiteral:
+		return []string{base + string(re.Rune)}, isCaseSensitive(re)
+	case syntax.OpEmptyMatch:
+		if base != "" {
+			return []string{base}, isCaseSensitive(re)
+		}
+	case syntax.OpAlternate:
+		return findSetMatchesFromAlternate(re, base)
+	case syntax.OpCapture:
+		clearCapture(re)
+		return findSetMatchesInternal(re, base)
+	case syntax.OpConcat:
+		return findSetMatchesFromConcat(re, base)
+	case syntax.OpCharClass:
+		if len(re.Rune)%2 != 0 {
+			return nil, false
+		}
+		var matches []string
+		var totalSet int
+		for i := 0; i+1 < len(re.Rune); i += 2 {
+			totalSet += int(re.Rune[i+1]-re.Rune[i]) + 1
+		}
+		// limits the total characters that can be used to create matches.
+		// In some case like negation [^0-9] a lot of possibilities exists and that
+		// can create thousands of possible matches at which points we're better off using regexp.
+		if totalSet > maxSetMatches {
+			return nil, false
+		}
+		for i := 0; i+1 < len(re.Rune); i += 2 {
+			lo, hi := re.Rune[i], re.Rune[i+1]
+			for c := lo; c <= hi; c++ {
+				matches = append(matches, base+string(c))
+			}
+		}
+		return matches, isCaseSensitive(re)
+	default:
+		return nil, false
+	}
+	return nil, false
+}
+
+func findSetMatchesFromConcat(re *syntax.Regexp, base string) (matches []string, matchesCaseSensitive bool) {
+	if len(re.Sub) == 0 {
+		return nil, false
+	}
+	clearCapture(re.Sub...)
+
+	matches = []string{base}
+
+	for i := 0; i < len(re.Sub); i++ {
+		var newMatches []string
+		for j, b := range matches {
+			m, caseSensitive := findSetMatchesInternal(re.Sub[i], b)
+			if m == nil {
+				return nil, false
+			}
+			if tooManyMatches(newMatches, m...) {
+				return nil, false
+			}
+
+			// All matches must have the same case sensitivity. If it's the first set of matches
+			// returned, we store its sensitivity as the expected case, and then we'll check all
+			// other ones.
+			if i == 0 && j == 0 {
+				matchesCaseSensitive = caseSensitive
+			}
+			if matchesCaseSensitive != caseSensitive {
+				return nil, false
+			}
+
+			newMatches = append(newMatches, m...)
+		}
+		matches = newMatches
+	}
+
+	return matches, matchesCaseSensitive
+}
+
+func findSetMatchesFromAlternate(re *syntax.Regexp, base string) (matches []string, matchesCaseSensitive bool) {
+	for i, sub := range re.Sub {
+		found, caseSensitive := findSetMatchesInternal(sub, base)
+		if found == nil {
+			return nil, false
+		}
+		if tooManyMatches(matches, found...) {
+			return nil, false
+		}
+
+		// All matches must have the same case sensitivity. If it's the first set of matches
+		// returned, we store its sensitivity as the expected case, and then we'll check all
+		// other ones.
+		if i == 0 {
+			matchesCaseSensitive = caseSensitive
+		}
+		if matchesCaseSensitive != caseSensitive {
+			return nil, false
+		}
+
+		matches = append(matches, found...)
+	}
+
+	return matches, matchesCaseSensitive
+}
+
+// clearCapture removes capture operation as they are not used for matching.
+func clearCapture(regs ...*syntax.Regexp) {
+	for _, r := range regs {
+		// Iterate on the regexp because capture groups could be nested.
+		for r.Op == syntax.OpCapture {
+			*r = *r.Sub[0]
+		}
+	}
+}
+
+// clearBeginEndText removes the begin and end text from the regexp. Prometheus regexp are anchored to the beginning and end of the string.
+func clearBeginEndText(re *syntax.Regexp) {
+	// Do not clear begin/end text from an alternate operator because it could
+	// change the actual regexp properties.
+	if re.Op == syntax.OpAlternate {
+		return
+	}
+
+	if len(re.Sub) == 0 {
+		return
+	}
+	if len(re.Sub) == 1 {
+		if re.Sub[0].Op == syntax.OpBeginText || re.Sub[0].Op == syntax.OpEndText {
+			// We need to remove this element. Since it's the only one, we convert into a matcher of an empty string.
+			// OpEmptyMatch is regexp's nop operator.
+			re.Op = syntax.OpEmptyMatch
+			re.Sub = nil
+			return
+		}
+	}
+	if re.Sub[0].Op == syntax.OpBeginText {
+		re.Sub = re.Sub[1:]
+	}
+	if re.Sub[len(re.Sub)-1].Op == syntax.OpEndText {
+		re.Sub = re.Sub[:len(re.Sub)-1]
+	}
+}
+
+// isCaseInsensitive tells if a regexp is case insensitive.
+// The flag should be check at each level of the syntax tree.
+func isCaseInsensitive(reg *syntax.Regexp) bool {
+	return (reg.Flags & syntax.FoldCase) != 0
+}
+
+// isCaseSensitive tells if a regexp is case sensitive.
+// The flag should be check at each level of the syntax tree.
+func isCaseSensitive(reg *syntax.Regexp) bool {
+	return !isCaseInsensitive(reg)
+}
+
+// tooManyMatches guards against creating too many set matches.
+func tooManyMatches(matches []string, added ...string) bool {
+	return len(matches)+len(added) > maxSetMatches
+}
+
+func (m *FastRegexMatcher) MatchString(s string) bool {
+	return m.matchString(s)
+}
+
+func (m *FastRegexMatcher) SetMatches() []string {
+	// IMPORTANT: always return a copy, otherwise if the caller manipulate this slice it will
+	// also get manipulated in the cached FastRegexMatcher instance.
+	return slices.Clone(m.setMatches)
+}
 
 func (m *FastRegexMatcher) GetRegexString() string {
-	if m.literal {
-		return m.value
-	}
-	return m.re.String()
+	return m.reString
 }
 
-func isLiteral(re string) bool {
-	return regexp.QuoteMeta(re) == re
+// optimizeAlternatingLiterals optimizes a regex of the form
+//
+//	`literal1|literal2|literal3|...`
+//
+// this function returns an optimized StringMatcher or nil if the regex
+// cannot be optimized in this way, and a list of setMatches up to maxSetMatches.
+func optimizeAlternatingLiterals(s string) (StringMatcher, []string) {
+	if len(s) == 0 {
+		return emptyStringMatcher{}, nil
+	}
+
+	estimatedAlternates := strings.Count(s, "|") + 1
+
+	// If there are no alternates, check if the string is a literal
+	if estimatedAlternates == 1 {
+		if regexp.QuoteMeta(s) == s {
+			return &equalStringMatcher{s: s, caseSensitive: true}, []string{s}
+		}
+		return nil, nil
+	}
+
+	multiMatcher := newEqualMultiStringMatcher(true, estimatedAlternates)
+
+	for end := strings.IndexByte(s, '|'); end > -1; end = strings.IndexByte(s, '|') {
+		// Split the string into the next literal and the remainder
+		subMatch := s[:end]
+		s = s[end+1:]
+
+		// break if any of the submatches are not literals
+		if regexp.QuoteMeta(subMatch) != subMatch {
+			return nil, nil
+		}
+
+		multiMatcher.add(subMatch)
+	}
+
+	// break if the remainder is not a literal
+	if regexp.QuoteMeta(s) != s {
+		return nil, nil
+	}
+	multiMatcher.add(s)
+
+	return multiMatcher, multiMatcher.setMatches()
 }
 
 // optimizeConcatRegex returns literal prefix/suffix text that can be safely
@@ -123,3 +398,540 @@ func optimizeConcatRegex(r *syntax.Regexp) (prefix, suffix, contains string) {
 
 	return
 }
+
+// StringMatcher is a matcher that matches a string in place of a regular expression.
+type StringMatcher interface {
+	Matches(s string) bool
+}
+
+// stringMatcherFromRegexp attempts to replace a common regexp with a string matcher.
+// It returns nil if the regexp is not supported.
+func stringMatcherFromRegexp(re *syntax.Regexp) StringMatcher {
+	clearBeginEndText(re)
+
+	m := stringMatcherFromRegexpInternal(re)
+	m = optimizeEqualStringMatchers(m, minEqualMultiStringMatcherMapThreshold)
+
+	return m
+}
+
+func stringMatcherFromRegexpInternal(re *syntax.Regexp) StringMatcher {
+	clearCapture(re)
+
+	switch re.Op {
+	case syntax.OpBeginText:
+		// Correctly handling the begin text operator inside a regex is tricky,
+		// so in this case we fallback to the regex engine.
+		return nil
+	case syntax.OpEndText:
+		// Correctly handling the end text operator inside a regex is tricky,
+		// so in this case we fallback to the regex engine.
+		return nil
+	case syntax.OpPlus:
+		if re.Sub[0].Op != syntax.OpAnyChar && re.Sub[0].Op != syntax.OpAnyCharNotNL {
+			return nil
+		}
+		return &anyNonEmptyStringMatcher{
+			matchNL: re.Sub[0].Op == syntax.OpAnyChar,
+		}
+	case syntax.OpStar:
+		if re.Sub[0].Op != syntax.OpAnyChar && re.Sub[0].Op != syntax.OpAnyCharNotNL {
+			return nil
+		}
+
+		// If the newline is valid, than this matcher literally match any string (even empty).
+		if re.Sub[0].Op == syntax.OpAnyChar {
+			return trueMatcher{}
+		}
+
+		// Any string is fine (including an empty one), as far as it doesn't contain any newline.
+		return anyStringWithoutNewlineMatcher{}
+	case syntax.OpQuest:
+		// Only optimize for ".?".
+		if len(re.Sub) != 1 || (re.Sub[0].Op != syntax.OpAnyChar && re.Sub[0].Op != syntax.OpAnyCharNotNL) {
+			return nil
+		}
+
+		return &zeroOrOneCharacterStringMatcher{
+			matchNL: re.Sub[0].Op == syntax.OpAnyChar,
+		}
+	case syntax.OpEmptyMatch:
+		return emptyStringMatcher{}
+
+	case syntax.OpLiteral:
+		return &equalStringMatcher{
+			s:             string(re.Rune),
+			caseSensitive: !isCaseInsensitive(re),
+		}
+	case syntax.OpAlternate:
+		or := make([]StringMatcher, 0, len(re.Sub))
+		for _, sub := range re.Sub {
+			m := stringMatcherFromRegexpInternal(sub)
+			if m == nil {
+				return nil
+			}
+			or = append(or, m)
+		}
+		return orStringMatcher(or)
+	case syntax.OpConcat:
+		clearCapture(re.Sub...)
+
+		if len(re.Sub) == 0 {
+			return emptyStringMatcher{}
+		}
+		if len(re.Sub) == 1 {
+			return stringMatcherFromRegexpInternal(re.Sub[0])
+		}
+
+		var left, right StringMatcher
+
+		// Let's try to find if there's a first and last any matchers.
+		if re.Sub[0].Op == syntax.OpPlus || re.Sub[0].Op == syntax.OpStar || re.Sub[0].Op == syntax.OpQuest {
+			left = stringMatcherFromRegexpInternal(re.Sub[0])
+			if left == nil {
+				return nil
+			}
+			re.Sub = re.Sub[1:]
+		}
+		if re.Sub[len(re.Sub)-1].Op == syntax.OpPlus || re.Sub[len(re.Sub)-1].Op == syntax.OpStar || re.Sub[len(re.Sub)-1].Op == syntax.OpQuest {
+			right = stringMatcherFromRegexpInternal(re.Sub[len(re.Sub)-1])
+			if right == nil {
+				return nil
+			}
+			re.Sub = re.Sub[:len(re.Sub)-1]
+		}
+
+		matches, matchesCaseSensitive := findSetMatchesInternal(re, "")
+
+		if len(matches) == 0 && len(re.Sub) == 2 {
+			// We have not find fixed set matches. We look for other known cases that
+			// we can optimize.
+			switch {
+			// Prefix is literal.
+			case right == nil && re.Sub[0].Op == syntax.OpLiteral:
+				right = stringMatcherFromRegexpInternal(re.Sub[1])
+				if right != nil {
+					matches = []string{string(re.Sub[0].Rune)}
+					matchesCaseSensitive = !isCaseInsensitive(re.Sub[0])
+				}
+
+			// Suffix is literal.
+			case left == nil && re.Sub[1].Op == syntax.OpLiteral:
+				left = stringMatcherFromRegexpInternal(re.Sub[0])
+				if left != nil {
+					matches = []string{string(re.Sub[1].Rune)}
+					matchesCaseSensitive = !isCaseInsensitive(re.Sub[1])
+				}
+			}
+		}
+
+		// Ensure we've found some literals to match (optionally with a left and/or right matcher).
+		// If not, then this optimization doesn't trigger.
+		if len(matches) == 0 {
+			return nil
+		}
+
+		// Use the right (and best) matcher based on what we've found.
+		switch {
+		// No left and right matchers (only fixed set matches).
+		case left == nil && right == nil:
+			// if there's no any matchers on both side it's a concat of literals
+			or := make([]StringMatcher, 0, len(matches))
+			for _, match := range matches {
+				or = append(or, &equalStringMatcher{
+					s:             match,
+					caseSensitive: matchesCaseSensitive,
+				})
+			}
+			return orStringMatcher(or)
+
+		// Right matcher with 1 fixed set match.
+		case left == nil && len(matches) == 1:
+			return &literalPrefixStringMatcher{
+				prefix:              matches[0],
+				prefixCaseSensitive: matchesCaseSensitive,
+				right:               right,
+			}
+
+		// Left matcher with 1 fixed set match.
+		case right == nil && len(matches) == 1:
+			return &literalSuffixStringMatcher{
+				left:                left,
+				suffix:              matches[0],
+				suffixCaseSensitive: matchesCaseSensitive,
+			}
+
+		// We found literals in the middle. We can trigger the fast path only if
+		// the matches are case sensitive because containsStringMatcher doesn't
+		// support case insensitive.
+		case matchesCaseSensitive:
+			return &containsStringMatcher{
+				substrings: matches,
+				left:       left,
+				right:      right,
+			}
+		}
+	}
+	return nil
+}
+
+// containsStringMatcher matches a string if it contains any of the substrings.
+// If left and right are not nil, it's a contains operation where left and right must match.
+// If left is nil, it's a hasPrefix operation and right must match.
+// Finally, if right is nil it's a hasSuffix operation and left must match.
+type containsStringMatcher struct {
+	// The matcher that must match the left side. Can be nil.
+	left StringMatcher
+
+	// At least one of these strings must match in the "middle", between left and right matchers.
+	substrings []string
+
+	// The matcher that must match the right side. Can be nil.
+	right StringMatcher
+}
+
+func (m *containsStringMatcher) Matches(s string) bool {
+	for _, substr := range m.substrings {
+		switch {
+		case m.right != nil && m.left != nil:
+			searchStartPos := 0
+
+			for {
+				pos := strings.Index(s[searchStartPos:], substr)
+				if pos < 0 {
+					break
+				}
+
+				// Since we started searching from searchStartPos, we have to add that offset
+				// to get the actual position of the substring inside the text.
+				pos += searchStartPos
+
+				// If both the left and right matchers match, then we can stop searching because
+				// we've found a match.
+				if m.left.Matches(s[:pos]) && m.right.Matches(s[pos+len(substr):]) {
+					return true
+				}
+
+				// Continue searching for another occurrence of the substring inside the text.
+				searchStartPos = pos + 1
+			}
+		case m.left != nil:
+			// If we have to check for characters on the left then we need to match a suffix.
+			if strings.HasSuffix(s, substr) && m.left.Matches(s[:len(s)-len(substr)]) {
+				return true
+			}
+		case m.right != nil:
+			if strings.HasPrefix(s, substr) && m.right.Matches(s[len(substr):]) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// literalPrefixStringMatcher matches a string with the given literal prefix and right side matcher.
+type literalPrefixStringMatcher struct {
+	prefix              string
+	prefixCaseSensitive bool
+
+	// The matcher that must match the right side. Can be nil.
+	right StringMatcher
+}
+
+func (m *literalPrefixStringMatcher) Matches(s string) bool {
+	// Ensure the prefix matches.
+	if m.prefixCaseSensitive && !strings.HasPrefix(s, m.prefix) {
+		return false
+	}
+	if !m.prefixCaseSensitive && !hasPrefixCaseInsensitive(s, m.prefix) {
+		return false
+	}
+
+	// Ensure the right side matches.
+	return m.right.Matches(s[len(m.prefix):])
+}
+
+// literalSuffixStringMatcher matches a string with the given literal suffix and left side matcher.
+type literalSuffixStringMatcher struct {
+	// The matcher that must match the left side. Can be nil.
+	left StringMatcher
+
+	suffix              string
+	suffixCaseSensitive bool
+}
+
+func (m *literalSuffixStringMatcher) Matches(s string) bool {
+	// Ensure the suffix matches.
+	if m.suffixCaseSensitive && !strings.HasSuffix(s, m.suffix) {
+		return false
+	}
+	if !m.suffixCaseSensitive && !hasSuffixCaseInsensitive(s, m.suffix) {
+		return false
+	}
+
+	// Ensure the left side matches.
+	return m.left.Matches(s[:len(s)-len(m.suffix)])
+}
+
+// emptyStringMatcher matches an empty string.
+type emptyStringMatcher struct{}
+
+func (m emptyStringMatcher) Matches(s string) bool {
+	return len(s) == 0
+}
+
+// orStringMatcher matches any of the sub-matchers.
+type orStringMatcher []StringMatcher
+
+func (m orStringMatcher) Matches(s string) bool {
+	for _, matcher := range m {
+		if matcher.Matches(s) {
+			return true
+		}
+	}
+	return false
+}
+
+// equalStringMatcher matches a string exactly and support case insensitive.
+type equalStringMatcher struct {
+	s             string
+	caseSensitive bool
+}
+
+func (m *equalStringMatcher) Matches(s string) bool {
+	if m.caseSensitive {
+		return m.s == s
+	}
+	return strings.EqualFold(m.s, s)
+}
+
+type multiStringMatcherBuilder interface {
+	StringMatcher
+	add(s string)
+	setMatches() []string
+}
+
+func newEqualMultiStringMatcher(caseSensitive bool, estimatedSize int) multiStringMatcherBuilder {
+	// If the estimated size is low enough, it's faster to use a slice instead of a map.
+	if estimatedSize < minEqualMultiStringMatcherMapThreshold {
+		return &equalMultiStringSliceMatcher{caseSensitive: caseSensitive, values: make([]string, 0, estimatedSize)}
+	}
+
+	return &equalMultiStringMapMatcher{
+		values:        make(map[string]struct{}, estimatedSize),
+		caseSensitive: caseSensitive,
+	}
+}
+
+// equalMultiStringSliceMatcher matches a string exactly against a slice of valid values.
+type equalMultiStringSliceMatcher struct {
+	values []string
+
+	caseSensitive bool
+}
+
+func (m *equalMultiStringSliceMatcher) add(s string) {
+	m.values = append(m.values, s)
+}
+
+func (m *equalMultiStringSliceMatcher) setMatches() []string {
+	return m.values
+}
+
+func (m *equalMultiStringSliceMatcher) Matches(s string) bool {
+	if m.caseSensitive {
+		for _, v := range m.values {
+			if s == v {
+				return true
+			}
+		}
+	} else {
+		for _, v := range m.values {
+			if strings.EqualFold(s, v) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// equalMultiStringMapMatcher matches a string exactly against a map of valid values.
+type equalMultiStringMapMatcher struct {
+	// values contains values to match a string against. If the matching is case insensitive,
+	// the values here must be lowercase.
+	values map[string]struct{}
+
+	caseSensitive bool
+}
+
+func (m *equalMultiStringMapMatcher) add(s string) {
+	if !m.caseSensitive {
+		s = strings.ToLower(s)
+	}
+
+	m.values[s] = struct{}{}
+}
+
+func (m *equalMultiStringMapMatcher) setMatches() []string {
+	if len(m.values) >= maxSetMatches {
+		return nil
+	}
+
+	matches := make([]string, 0, len(m.values))
+	for s := range m.values {
+		matches = append(matches, s)
+	}
+	return matches
+}
+
+func (m *equalMultiStringMapMatcher) Matches(s string) bool {
+	if !m.caseSensitive {
+		s = strings.ToLower(s)
+	}
+
+	_, ok := m.values[s]
+	return ok
+}
+
+// anyStringWithoutNewlineMatcher is a stringMatcher which matches any string
+// (including an empty one) as far as it doesn't contain any newline character.
+type anyStringWithoutNewlineMatcher struct{}
+
+func (m anyStringWithoutNewlineMatcher) Matches(s string) bool {
+	// We need to make sure it doesn't contain a newline. Since the newline is
+	// an ASCII character, we can use strings.IndexByte().
+	return strings.IndexByte(s, '\n') == -1
+}
+
+// anyNonEmptyStringMatcher is a stringMatcher which matches any non-empty string.
+type anyNonEmptyStringMatcher struct {
+	matchNL bool
+}
+
+func (m *anyNonEmptyStringMatcher) Matches(s string) bool {
+	if m.matchNL {
+		// It's OK if the string contains a newline so we just need to make
+		// sure it's non-empty.
+		return len(s) > 0
+	}
+
+	// We need to make sure it non-empty and doesn't contain a newline.
+	// Since the newline is an ASCII character, we can use strings.IndexByte().
+	return len(s) > 0 && strings.IndexByte(s, '\n') == -1
+}
+
+// zeroOrOneCharacterStringMatcher is a StringMatcher which matches zero or one occurrence
+// of any character. The newline character is matches only if matchNL is set to true.
+type zeroOrOneCharacterStringMatcher struct {
+	matchNL bool
+}
+
+func (m *zeroOrOneCharacterStringMatcher) Matches(s string) bool {
+	// Zero or one.
+	if len(s) > 1 {
+		return false
+	}
+
+	// No need to check for the newline if the string is empty or matching a newline is OK.
+	if m.matchNL || len(s) == 0 {
+		return true
+	}
+
+	return s[0] != '\n'
+}
+
+// trueMatcher is a stringMatcher which matches any string (always returns true).
+type trueMatcher struct{}
+
+func (m trueMatcher) Matches(_ string) bool {
+	return true
+}
+
+// optimizeEqualStringMatchers optimize a specific case where all matchers are made by an
+// alternation (orStringMatcher) of strings checked for equality (equalStringMatcher). In
+// this specific case, when we have many strings to match against we can use a map instead
+// of iterating over the list of strings.
+func optimizeEqualStringMatchers(input StringMatcher, threshold int) StringMatcher {
+	var (
+		caseSensitive    bool
+		caseSensitiveSet bool
+		numValues        int
+	)
+
+	// Analyse the input StringMatcher to count the number of occurrences
+	// and ensure all of them have the same case sensitivity.
+	analyseCallback := func(matcher *equalStringMatcher) bool {
+		// Ensure we don't have mixed case sensitivity.
+		if caseSensitiveSet && caseSensitive != matcher.caseSensitive {
+			return false
+		} else if !caseSensitiveSet {
+			caseSensitive = matcher.caseSensitive
+			caseSensitiveSet = true
+		}
+
+		numValues++
+		return true
+	}
+
+	if !findEqualStringMatchers(input, analyseCallback) {
+		return input
+	}
+
+	// If the number of values found is less than the threshold, then we should skip the optimization.
+	if numValues < threshold {
+		return input
+	}
+
+	// Parse again the input StringMatcher to extract all values and storing them.
+	// We can skip the case sensitivity check because we've already checked it and
+	// if the code reach this point then it means all matchers have the same case sensitivity.
+	multiMatcher := newEqualMultiStringMatcher(caseSensitive, numValues)
+
+	// Ignore the return value because we already iterated over the input StringMatcher
+	// and it was all good.
+	findEqualStringMatchers(input, func(matcher *equalStringMatcher) bool {
+		multiMatcher.add(matcher.s)
+		return true
+	})
+
+	return multiMatcher
+}
+
+// findEqualStringMatchers analyze the input StringMatcher and calls the callback for each
+// equalStringMatcher found. Returns true if and only if the input StringMatcher is *only*
+// composed by an alternation of equalStringMatcher.
+func findEqualStringMatchers(input StringMatcher, callback func(matcher *equalStringMatcher) bool) bool {
+	orInput, ok := input.(orStringMatcher)
+	if !ok {
+		return false
+	}
+
+	for _, m := range orInput {
+		switch casted := m.(type) {
+		case orStringMatcher:
+			if !findEqualStringMatchers(m, callback) {
+				return false
+			}
+
+		case *equalStringMatcher:
+			if !callback(casted) {
+				return false
+			}
+
+		default:
+			// It's not an equal string matcher, so we have to stop searching
+			// cause this optimization can't be applied.
+			return false
+		}
+	}
+
+	return true
+}
+
+func hasPrefixCaseInsensitive(s, prefix string) bool {
+	return len(s) >= len(prefix) && strings.EqualFold(s[0:len(prefix)], prefix)
+}
+
+func hasSuffixCaseInsensitive(s, suffix string) bool {
+	return len(s) >= len(suffix) && strings.EqualFold(s[len(s)-len(suffix):], suffix)
+}

promql/engine_test.go

@@ -3212,6 +3212,24 @@ func TestRangeQuery(t *testing.T) {
 			End:      time.Unix(120, 0),
 			Interval: 1 * time.Minute,
 		},
+		{
+			Name: "drop-metric-name",
+			Load: `load 30s
+							requests{job="1", __address__="bar"} 100`,
+			Query: `requests * 2`,
+			Result: Matrix{
+				Series{
+					Floats: []FPoint{{F: 200, T: 0}, {F: 200, T: 60000}, {F: 200, T: 120000}},
+					Metric: labels.FromStrings(
+						"__address__", "bar",
+						"job", "1",
+					),
+				},
+			},
+			Start:    time.Unix(0, 0),
+			End:      time.Unix(120, 0),
+			Interval: 1 * time.Minute,
+		},
 	}
 	for _, c := range cases {
 		t.Run(c.Name, func(t *testing.T) {
@@ -3496,7 +3514,39 @@ func TestNativeHistogram_HistogramStdDevVar(t *testing.T) {
 				},
 				NegativeBuckets: []int64{1, 0},
 			},
-			stdVar: 1544.8582535368798, // actual variance: 1738.4082
+			stdVar: 1844.4651144196398, // actual variance: 1738.4082
+		},
+		{
+			name: "-100000, -10000, -1000, -888, -888, -100, -50, -9, -8, -3",
+			h: &histogram.Histogram{
+				Count:     10,
+				ZeroCount: 0,
+				Sum:       -112946,
+				Schema:    0,
+				NegativeSpans: []histogram.Span{
+					{Offset: 2, Length: 3},
+					{Offset: 1, Length: 2},
+					{Offset: 2, Length: 1},
+					{Offset: 3, Length: 1},
+					{Offset: 2, Length: 1},
+				},
+				NegativeBuckets: []int64{1, 0, 0, 0, 0, 2, -2, 0},
+			},
+			stdVar: 759352122.1939945, // actual variance: 882690990
+		},
+		{
+			name: "-10 x10",
+			h: &histogram.Histogram{
+				Count:     10,
+				ZeroCount: 0,
+				Sum:       -100,
+				Schema:    0,
+				NegativeSpans: []histogram.Span{
+					{Offset: 4, Length: 1},
+				},
+				NegativeBuckets: []int64{10},
+			},
+			stdVar: 1.725830020304794, // actual variance: 0
 		},
 		{
 			name: "-50, -8, 0, 3, 8, 9, 100, NaN",

promql/functions.go

@@ -1154,11 +1154,17 @@ func funcHistogramStdDev(vals []parser.Value, args parser.Expressions, enh *Eval
 		it := sample.H.AllBucketIterator()
 		for it.Next() {
 			bucket := it.At()
+			if bucket.Count == 0 {
+				continue
+			}
 			var val float64
 			if bucket.Lower <= 0 && 0 <= bucket.Upper {
 				val = 0
 			} else {
 				val = math.Sqrt(bucket.Upper * bucket.Lower)
+				if bucket.Upper < 0 {
+					val = -val
+				}
 			}
 			delta := val - mean
 			variance, cVariance = kahanSumInc(bucket.Count*delta*delta, variance, cVariance)
@@ -1187,11 +1193,17 @@ func funcHistogramStdVar(vals []parser.Value, args parser.Expressions, enh *Eval
 		it := sample.H.AllBucketIterator()
 		for it.Next() {
 			bucket := it.At()
+			if bucket.Count == 0 {
+				continue
+			}
 			var val float64
 			if bucket.Lower <= 0 && 0 <= bucket.Upper {
 				val = 0
 			} else {
 				val = math.Sqrt(bucket.Upper * bucket.Lower)
+				if bucket.Upper < 0 {
+					val = -val
+				}
 			}
 			delta := val - mean
 			variance, cVariance = kahanSumInc(bucket.Count*delta*delta, variance, cVariance)
@@ -1429,6 +1441,9 @@ func (ev *evaluator) evalLabelJoin(args parser.Expressions) (parser.Value, annot
 		}
 		srcLabels[i-3] = src
 	}
+	if !model.LabelName(dst).IsValid() {
+		panic(fmt.Errorf("invalid destination label name in label_join(): %s", dst))
+	}
 
 	val, ws := ev.eval(args[0])
 	matrix := val.(Matrix)

promql/parser/parse_test.go

@@ -3706,7 +3706,31 @@ func TestParseExpressions(t *testing.T) {
 
 			if !test.fail {
 				require.NoError(t, err)
-				require.Equal(t, test.expected, expr, "error on input '%s'", test.input)
+				expected := test.expected
+
+				// The FastRegexMatcher is not comparable with a deep equal, so only compare its String() version.
+				if actualVector, ok := expr.(*VectorSelector); ok {
+					require.IsType(t, &VectorSelector{}, test.expected, "error on input '%s'", test.input)
+					expectedVector := test.expected.(*VectorSelector)
+
+					require.Len(t, actualVector.LabelMatchers, len(expectedVector.LabelMatchers), "error on input '%s'", test.input)
+
+					for i := 0; i < len(actualVector.LabelMatchers); i++ {
+						expectedMatcher := expectedVector.LabelMatchers[i].String()
+						actualMatcher := actualVector.LabelMatchers[i].String()
+
+						require.Equal(t, expectedMatcher, actualMatcher, "unexpected label matcher '%s' on input '%s'", actualMatcher, test.input)
+					}
+
+					// Make a shallow copy of the expected expr (because the test cases are defined in a global variable)
+					// and then reset the LabelMatcher to not compared them with the following deep equal.
+					expectedCopy := *expectedVector
+					expectedCopy.LabelMatchers = nil
+					expected = &expectedCopy
+					actualVector.LabelMatchers = nil
+				}
+
+				require.Equal(t, expected, expr, "error on input '%s'", test.input)
 			} else {
 				require.Error(t, err)
 				require.Contains(t, err.Error(), test.errMsg, "unexpected error on input '%s', expected '%s', got '%s'", test.input, test.errMsg, err.Error())

promql/test.go

@@ -46,6 +46,7 @@ var (
 	patSpace       = regexp.MustCompile("[\t ]+")
 	patLoad        = regexp.MustCompile(`^load\s+(.+?)$`)
 	patEvalInstant = regexp.MustCompile(`^eval(?:_(fail|ordered))?\s+instant\s+(?:at\s+(.+?))?\s+(.+)$`)
+	patEvalRange   = regexp.MustCompile(`^eval(?:_(fail))?\s+range\s+from\s+(.+)\s+to\s+(.+)\s+step\s+(.+?)\s+(.+)$`)
 )
 
 const (
@@ -72,7 +73,7 @@ func LoadedStorage(t testutil.T, input string) *teststorage.TestStorage {
 }
 
 // RunBuiltinTests runs an acceptance test suite against the provided engine.
-func RunBuiltinTests(t *testing.T, engine engineQuerier) {
+func RunBuiltinTests(t *testing.T, engine QueryEngine) {
 	t.Cleanup(func() { parser.EnableExperimentalFunctions = false })
 	parser.EnableExperimentalFunctions = true
 
@@ -89,11 +90,19 @@ func RunBuiltinTests(t *testing.T, engine engineQuerier) {
 }
 
 // RunTest parses and runs the test against the provided engine.
-func RunTest(t testutil.T, input string, engine engineQuerier) {
-	test, err := newTest(t, input)
-	require.NoError(t, err)
+func RunTest(t testutil.T, input string, engine QueryEngine) {
+	require.NoError(t, runTest(t, input, engine))
+}
 
+func runTest(t testutil.T, input string, engine QueryEngine) error {
+	test, err := newTest(t, input)
+
+	// Why do this before checking err? newTest() can create the test storage and then return an error,
+	// and we want to make sure to clean that up to avoid leaking goroutines.
 	defer func() {
+		if test == nil {
+			return
+		}
 		if test.storage != nil {
 			test.storage.Close()
 		}
@@ -102,13 +111,21 @@ func RunTest(t testutil.T, input string, engine engineQuerier) {
 		}
 	}()
 
+	if err != nil {
+		return err
+	}
+
 	for _, cmd := range test.cmds {
+		if err := test.exec(cmd, engine); err != nil {
 			// TODO(fabxc): aggregate command errors, yield diffs for result
 			// comparison errors.
-		require.NoError(t, test.exec(cmd, engine))
+			return err
 		}
 	}
 
+	return nil
+}
+
 // test is a sequence of read and write commands that are run
 // against a test storage.
 type test struct {
@@ -137,11 +154,6 @@ func newTest(t testutil.T, input string) (*test, error) {
 //go:embed testdata
 var testsFs embed.FS
 
-type engineQuerier interface {
-	NewRangeQuery(ctx context.Context, q storage.Queryable, opts QueryOpts, qs string, start, end time.Time, interval time.Duration) (Query, error)
-	NewInstantQuery(ctx context.Context, q storage.Queryable, opts QueryOpts, qs string, ts time.Time) (Query, error)
-}
-
 func raise(line int, format string, v ...interface{}) error {
 	return &parser.ParseErr{
 		LineOffset: line,
@@ -188,15 +200,26 @@ func parseSeries(defLine string, line int) (labels.Labels, []parser.SequenceValu
 }
 
 func (t *test) parseEval(lines []string, i int) (int, *evalCmd, error) {
-	if !patEvalInstant.MatchString(lines[i]) {
-		return i, nil, raise(i, "invalid evaluation command. (eval[_fail|_ordered] instant [at <offset:duration>] <query>")
+	instantParts := patEvalInstant.FindStringSubmatch(lines[i])
+	rangeParts := patEvalRange.FindStringSubmatch(lines[i])
+
+	if instantParts == nil && rangeParts == nil {
+		return i, nil, raise(i, "invalid evaluation command. Must be either 'eval[_fail|_ordered] instant [at <offset:duration>] <query>' or 'eval[_fail] range from <from> to <to> step <step> <query>'")
 	}
-	parts := patEvalInstant.FindStringSubmatch(lines[i])
-	var (
-		mod  = parts[1]
-		at   = parts[2]
-		expr = parts[3]
-	)
+
+	isInstant := instantParts != nil
+
+	var mod string
+	var expr string
+
+	if isInstant {
+		mod = instantParts[1]
+		expr = instantParts[3]
+	} else {
+		mod = rangeParts[1]
+		expr = rangeParts[5]
+	}
+
 	_, err := parser.ParseExpr(expr)
 	if err != nil {
 		parser.EnrichParseError(err, func(parseErr *parser.ParseErr) {
@@ -209,15 +232,54 @@ func (t *test) parseEval(lines []string, i int) (int, *evalCmd, error) {
 		return i, nil, err
 	}
 
+	formatErr := func(format string, args ...any) error {
+		combinedArgs := []any{expr, i + 1}
+
+		combinedArgs = append(combinedArgs, args...)
+		return fmt.Errorf("error in eval %s (line %v): "+format, combinedArgs...)
+	}
+
+	var cmd *evalCmd
+
+	if isInstant {
+		at := instantParts[2]
 		offset, err := model.ParseDuration(at)
 		if err != nil {
-		return i, nil, raise(i, "invalid step definition %q: %s", parts[1], err)
+			return i, nil, formatErr("invalid timestamp definition %q: %s", at, err)
 		}
 		ts := testStartTime.Add(time.Duration(offset))
+		cmd = newInstantEvalCmd(expr, ts, i+1)
+	} else {
+		from := rangeParts[2]
+		to := rangeParts[3]
+		step := rangeParts[4]
+
+		parsedFrom, err := model.ParseDuration(from)
+		if err != nil {
+			return i, nil, formatErr("invalid start timestamp definition %q: %s", from, err)
+		}
+
+		parsedTo, err := model.ParseDuration(to)
+		if err != nil {
+			return i, nil, formatErr("invalid end timestamp definition %q: %s", to, err)
+		}
+
+		if parsedTo < parsedFrom {
+			return i, nil, formatErr("invalid test definition, end timestamp (%s) is before start timestamp (%s)", to, from)
+		}
+
+		parsedStep, err := model.ParseDuration(step)
+		if err != nil {
+			return i, nil, formatErr("invalid step definition %q: %s", step, err)
+		}
+
+		cmd = newRangeEvalCmd(expr, testStartTime.Add(time.Duration(parsedFrom)), testStartTime.Add(time.Duration(parsedTo)), time.Duration(parsedStep), i+1)
+	}
 
-	cmd := newEvalCmd(expr, ts, i+1)
 	switch mod {
 	case "ordered":
+		// Ordered results are not supported for range queries, but the regex for range query commands does not allow
+		// asserting an ordered result, so we don't need to do any error checking here.
 		cmd.ordered = true
 	case "fail":
 		cmd.fail = true
@@ -240,8 +302,8 @@ func (t *test) parseEval(lines []string, i int) (int, *evalCmd, error) {
 		}
 
 		// Currently, we are not expecting any matrices.
-		if len(vals) > 1 {
-			return i, nil, raise(i, "expecting multiple values in instant evaluation not allowed")
+		if len(vals) > 1 && isInstant {
+			return i, nil, formatErr("expecting multiple values in instant evaluation not allowed")
 		}
 		cmd.expectMetric(j, metric, vals...)
 	}
@@ -375,8 +437,11 @@ func appendSample(a storage.Appender, s Sample, m labels.Labels) error {
 type evalCmd struct {
 	expr  string
 	start time.Time
+	end   time.Time
+	step  time.Duration
 	line  int
 
+	isRange       bool // if false, instant query
 	fail, ordered bool
 
 	metrics  map[uint64]labels.Labels
@@ -392,7 +457,7 @@ func (e entry) String() string {
 	return fmt.Sprintf("%d: %s", e.pos, e.vals)
 }
 
-func newEvalCmd(expr string, start time.Time, line int) *evalCmd {
+func newInstantEvalCmd(expr string, start time.Time, line int) *evalCmd {
 	return &evalCmd{
 		expr:  expr,
 		start: start,
@@ -403,6 +468,20 @@ func newEvalCmd(expr string, start time.Time, line int) *evalCmd {
 	}
 }
 
+func newRangeEvalCmd(expr string, start, end time.Time, step time.Duration, line int) *evalCmd {
+	return &evalCmd{
+		expr:    expr,
+		start:   start,
+		end:     end,
+		step:    step,
+		line:    line,
+		isRange: true,
+
+		metrics:  map[uint64]labels.Labels{},
+		expected: map[uint64]entry{},
+	}
+}
+
 func (ev *evalCmd) String() string {
 	return "eval"
 }
@@ -425,7 +504,77 @@ func (ev *evalCmd) expectMetric(pos int, m labels.Labels, vals ...parser.Sequenc
 func (ev *evalCmd) compareResult(result parser.Value) error {
 	switch val := result.(type) {
 	case Matrix:
-		return errors.New("received range result on instant evaluation")
+		if ev.ordered {
+			return fmt.Errorf("expected ordered result, but query returned a matrix")
+		}
+
+		if err := assertMatrixSorted(val); err != nil {
+			return err
+		}
+
+		seen := map[uint64]bool{}
+		for _, s := range val {
+			hash := s.Metric.Hash()
+			if _, ok := ev.metrics[hash]; !ok {
+				return fmt.Errorf("unexpected metric %s in result", s.Metric)
+			}
+			seen[hash] = true
+			exp := ev.expected[hash]
+
+			var expectedFloats []FPoint
+			var expectedHistograms []HPoint
+
+			for i, e := range exp.vals {
+				ts := ev.start.Add(time.Duration(i) * ev.step)
+
+				if ts.After(ev.end) {
+					return fmt.Errorf("expected %v points for %s, but query time range cannot return this many points", len(exp.vals), ev.metrics[hash])
+				}
+
+				t := ts.UnixNano() / int64(time.Millisecond/time.Nanosecond)
+
+				if e.Histogram != nil {
+					expectedHistograms = append(expectedHistograms, HPoint{T: t, H: e.Histogram})
+				} else if !e.Omitted {
+					expectedFloats = append(expectedFloats, FPoint{T: t, F: e.Value})
+				}
+			}
+
+			if len(expectedFloats) != len(s.Floats) || len(expectedHistograms) != len(s.Histograms) {
+				return fmt.Errorf("expected %v float points and %v histogram points for %s, but got %s", len(expectedFloats), len(expectedHistograms), ev.metrics[hash], formatSeriesResult(s))
+			}
+
+			for i, expected := range expectedFloats {
+				actual := s.Floats[i]
+
+				if expected.T != actual.T {
+					return fmt.Errorf("expected float value at index %v for %s to have timestamp %v, but it had timestamp %v (result has %s)", i, ev.metrics[hash], expected.T, actual.T, formatSeriesResult(s))
+				}
+
+				if !almostEqual(actual.F, expected.F, defaultEpsilon) {
+					return fmt.Errorf("expected float value at index %v (t=%v) for %s to be %v, but got %v (result has %s)", i, actual.T, ev.metrics[hash], expected.F, actual.F, formatSeriesResult(s))
+				}
+			}
+
+			for i, expected := range expectedHistograms {
+				actual := s.Histograms[i]
+
+				if expected.T != actual.T {
+					return fmt.Errorf("expected histogram value at index %v for %s to have timestamp %v, but it had timestamp %v (result has %s)", i, ev.metrics[hash], expected.T, actual.T, formatSeriesResult(s))
+				}
+
+				if !actual.H.Equals(expected.H) {
+					return fmt.Errorf("expected histogram value at index %v (t=%v) for %s to be %v, but got %v (result has %s)", i, actual.T, ev.metrics[hash], expected.H, actual.H, formatSeriesResult(s))
+				}
+			}
+
+		}
+
+		for hash := range ev.expected {
+			if !seen[hash] {
+				return fmt.Errorf("expected metric %s not found", ev.metrics[hash])
+			}
+		}
 
 	case Vector:
 		seen := map[uint64]bool{}
@@ -440,7 +589,13 @@ func (ev *evalCmd) compareResult(result parser.Value) error {
 			}
 			exp0 := exp.vals[0]
 			expH := exp0.Histogram
-			if (expH == nil) != (v.H == nil) || (expH != nil && !expH.Equals(v.H)) {
+			if expH == nil && v.H != nil {
+				return fmt.Errorf("expected float value %v for %s but got histogram %s", exp0, v.Metric, HistogramTestExpression(v.H))
+			}
+			if expH != nil && v.H == nil {
+				return fmt.Errorf("expected histogram %s for %s but got float value %v", HistogramTestExpression(expH), v.Metric, v.F)
+			}
+			if expH != nil && !expH.Equals(v.H) {
 				return fmt.Errorf("expected %v for %s but got %s", HistogramTestExpression(expH), v.Metric, HistogramTestExpression(v.H))
 			}
 			if !almostEqual(exp0.Value, v.F, defaultEpsilon) {
@@ -477,6 +632,21 @@ func (ev *evalCmd) compareResult(result parser.Value) error {
 	return nil
 }
 
+func formatSeriesResult(s Series) string {
+	floatPlural := "s"
+	histogramPlural := "s"
+
+	if len(s.Floats) == 1 {
+		floatPlural = ""
+	}
+
+	if len(s.Histograms) == 1 {
+		histogramPlural = ""
+	}
+
+	return fmt.Sprintf("%v float point%s %v and %v histogram point%s %v", len(s.Floats), floatPlural, s.Floats, len(s.Histograms), histogramPlural, s.Histograms)
+}
+
 // HistogramTestExpression returns TestExpression() for the given histogram or "" if the histogram is nil.
 func HistogramTestExpression(h *histogram.FloatHistogram) string {
 	if h != nil {
@@ -561,7 +731,7 @@ func atModifierTestCases(exprStr string, evalTime time.Time) ([]atModifierTestCa
 }
 
 // exec processes a single step of the test.
-func (t *test) exec(tc testCommand, engine engineQuerier) error {
+func (t *test) exec(tc testCommand, engine QueryEngine) error {
 	switch cmd := tc.(type) {
 	case *clearCmd:
 		t.clear()
@@ -578,6 +748,48 @@ func (t *test) exec(tc testCommand, engine engineQuerier) error {
 		}
 
 	case *evalCmd:
+		return t.execEval(cmd, engine)
+
+	default:
+		panic("promql.Test.exec: unknown test command type")
+	}
+	return nil
+}
+
+func (t *test) execEval(cmd *evalCmd, engine QueryEngine) error {
+	if cmd.isRange {
+		return t.execRangeEval(cmd, engine)
+	}
+
+	return t.execInstantEval(cmd, engine)
+}
+
+func (t *test) execRangeEval(cmd *evalCmd, engine QueryEngine) error {
+	q, err := engine.NewRangeQuery(t.context, t.storage, nil, cmd.expr, cmd.start, cmd.end, cmd.step)
+	if err != nil {
+		return err
+	}
+	res := q.Exec(t.context)
+	if res.Err != nil {
+		if cmd.fail {
+			return nil
+		}
+
+		return fmt.Errorf("error evaluating query %q (line %d): %w", cmd.expr, cmd.line, res.Err)
+	}
+	if res.Err == nil && cmd.fail {
+		return fmt.Errorf("expected error evaluating query %q (line %d) but got none", cmd.expr, cmd.line)
+	}
+	defer q.Close()
+
+	if err := cmd.compareResult(res.Value); err != nil {
+		return fmt.Errorf("error in %s %s (line %d): %w", cmd, cmd.expr, cmd.line, err)
+	}
+
+	return nil
+}
+
+func (t *test) execInstantEval(cmd *evalCmd, engine QueryEngine) error {
 	queries, err := atModifierTestCases(cmd.expr, cmd.start)
 	if err != nil {
 		return err
@@ -616,10 +828,14 @@ func (t *test) exec(tc testCommand, engine engineQuerier) error {
 		}
 		defer q.Close()
 		if cmd.ordered {
-				// Ordering isn't defined for range queries.
+			// Range queries are always sorted by labels, so skip this test case that expects results in a particular order.
 			continue
 		}
 		mat := rangeRes.Value.(Matrix)
+		if err := assertMatrixSorted(mat); err != nil {
+			return err
+		}
+
 		vec := make(Vector, 0, len(mat))
 		for _, series := range mat {
 			// We expect either Floats or Histograms.
@@ -644,12 +860,25 @@ func (t *test) exec(tc testCommand, engine engineQuerier) error {
 		if err != nil {
 			return fmt.Errorf("error in %s %s (line %d) range mode: %w", cmd, iq.expr, cmd.line, err)
 		}
-
 	}
 
-	default:
-		panic("promql.Test.exec: unknown test command type")
+	return nil
 }
+
+func assertMatrixSorted(m Matrix) error {
+	if len(m) <= 1 {
+		return nil
+	}
+
+	for i, s := range m[:len(m)-1] {
+		nextIndex := i + 1
+		nextMetric := m[nextIndex].Metric
+
+		if labels.Compare(s.Metric, nextMetric) > 0 {
+			return fmt.Errorf("matrix results should always be sorted by labels, but matrix is not sorted: series at index %v with labels %s sorts before series at index %v with labels %s", nextIndex, nextMetric, i, s.Metric)
+		}
+	}
+
 	return nil
 }
 
@@ -704,8 +933,6 @@ func parseNumber(s string) (float64, error) {
 // LazyLoader lazily loads samples into storage.
 // This is specifically implemented for unit testing of rules.
 type LazyLoader struct {
-	testutil.T
-
 	loadCmd *loadCmd
 
 	storage          storage.Storage
@@ -727,13 +954,15 @@ type LazyLoaderOpts struct {
 }
 
 // NewLazyLoader returns an initialized empty LazyLoader.
-func NewLazyLoader(t testutil.T, input string, opts LazyLoaderOpts) (*LazyLoader, error) {
+func NewLazyLoader(input string, opts LazyLoaderOpts) (*LazyLoader, error) {
 	ll := &LazyLoader{
-		T:    t,
 		opts: opts,
 	}
 	err := ll.parse(input)
-	ll.clear()
+	if err != nil {
+		return nil, err
+	}
+	err = ll.clear()
 	return ll, err
 }
 
@@ -761,15 +990,20 @@ func (ll *LazyLoader) parse(input string) error {
 }
 
 // clear the current test storage of all inserted samples.
-func (ll *LazyLoader) clear() {
+func (ll *LazyLoader) clear() error {
 	if ll.storage != nil {
-		err := ll.storage.Close()
-		require.NoError(ll.T, err, "Unexpected error while closing test storage.")
+		if err := ll.storage.Close(); err != nil {
+			return fmt.Errorf("closing test storage: %w", err)
+		}
 	}
 	if ll.cancelCtx != nil {
 		ll.cancelCtx()
 	}
-	ll.storage = teststorage.New(ll)
+	var err error
+	ll.storage, err = teststorage.NewWithError()
+	if err != nil {
+		return err
+	}
 
 	opts := EngineOpts{
 		Logger:                   nil,
@@ -783,6 +1017,7 @@ func (ll *LazyLoader) clear() {
 
 	ll.queryEngine = NewEngine(opts)
 	ll.context, ll.cancelCtx = context.WithCancel(context.Background())
+	return nil
 }
 
 // appendTill appends the defined time series to the storage till the given timestamp (in milliseconds).
@@ -836,8 +1071,7 @@ func (ll *LazyLoader) Storage() storage.Storage {
 }
 
 // Close closes resources associated with the LazyLoader.
-func (ll *LazyLoader) Close() {
+func (ll *LazyLoader) Close() error {
 	ll.cancelCtx()
-	err := ll.storage.Close()
-	require.NoError(ll.T, err, "Unexpected error while closing test storage.")
+	return ll.storage.Close()
 }

promql/test_test.go

@@ -110,7 +110,7 @@ func TestLazyLoader_WithSamplesTill(t *testing.T) {
 	}
 
 	for _, c := range cases {
-		suite, err := NewLazyLoader(t, c.loadString, LazyLoaderOpts{})
+		suite, err := NewLazyLoader(c.loadString, LazyLoaderOpts{})
 		require.NoError(t, err)
 		defer suite.Close()
 
@@ -156,3 +156,354 @@ func TestLazyLoader_WithSamplesTill(t *testing.T) {
 		}
 	}
 }
+
+func TestRunTest(t *testing.T) {
+	testData := `
+load 5m
+	http_requests{job="api-server", instance="0", group="production"}	0+10x10
+	http_requests{job="api-server", instance="1", group="production"}	0+20x10
+	http_requests{job="api-server", instance="0", group="canary"}		0+30x10
+	http_requests{job="api-server", instance="1", group="canary"}		0+40x10
+`
+
+	testCases := map[string]struct {
+		input         string
+		expectedError string
+	}{
+		"instant query with expected float result": {
+			input: testData + `
+eval instant at 5m sum by (group) (http_requests)
+	{group="production"} 30
+	{group="canary"} 70
+`,
+		},
+		"instant query with unexpected float result": {
+			input: testData + `
+eval instant at 5m sum by (group) (http_requests)
+	{group="production"} 30
+	{group="canary"} 80
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected 80 for {group="canary"} but got 70`,
+		},
+		"instant query with expected histogram result": {
+			input: `
+load 5m
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}}
+
+eval instant at 0 testmetric
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}}
+`,
+		},
+		"instant query with unexpected histogram result": {
+			input: `
+load 5m
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}}
+
+eval instant at 0 testmetric
+	testmetric {{schema:-1 sum:6 count:1 buckets:[1] offset:1}}
+`,
+			expectedError: `error in eval testmetric (line 5): expected {{schema:-1 count:1 sum:6 offset:1 buckets:[1]}} for {__name__="testmetric"} but got {{schema:-1 count:1 sum:4 offset:1 buckets:[1]}}`,
+		},
+		"instant query with float value returned when histogram expected": {
+			input: `
+load 5m
+	testmetric 2
+
+eval instant at 0 testmetric
+	testmetric {{}}
+`,
+			expectedError: `error in eval testmetric (line 5): expected histogram {{}} for {__name__="testmetric"} but got float value 2`,
+		},
+		"instant query with histogram returned when float expected": {
+			input: `
+load 5m
+	testmetric {{}}
+
+eval instant at 0 testmetric
+	testmetric 2
+`,
+			expectedError: `error in eval testmetric (line 5): expected float value 2.000000 for {__name__="testmetric"} but got histogram {{}}`,
+		},
+		"instant query, but result has an unexpected series": {
+			input: testData + `
+eval instant at 5m sum by (group) (http_requests)
+	{group="production"} 30
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): unexpected metric {group="canary"} in result`,
+		},
+		"instant query, but result is missing a series": {
+			input: testData + `
+eval instant at 5m sum by (group) (http_requests)
+	{group="production"} 30
+	{group="canary"} 70
+	{group="test"} 100
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected metric {group="test"} with 3: [100.000000] not found`,
+		},
+		"instant query expected to fail, and query fails": {
+			input: `
+load 5m
+	testmetric1{src="a",dst="b"} 0
+	testmetric2{src="a",dst="b"} 1
+
+eval_fail instant at 0m ceil({__name__=~'testmetric1|testmetric2'})
+`,
+		},
+		"instant query expected to fail, but query succeeds": {
+			input:         `eval_fail instant at 0s vector(0)`,
+			expectedError: `expected error evaluating query "vector(0)" (line 1) but got none`,
+		},
+		"instant query with results expected to match provided order, and result is in expected order": {
+			input: testData + `
+eval_ordered instant at 50m sort(http_requests)
+	http_requests{group="production", instance="0", job="api-server"} 100
+	http_requests{group="production", instance="1", job="api-server"} 200
+	http_requests{group="canary", instance="0", job="api-server"} 300
+	http_requests{group="canary", instance="1", job="api-server"} 400
+`,
+		},
+		"instant query with results expected to match provided order, but result is out of order": {
+			input: testData + `
+eval_ordered instant at 50m sort(http_requests)
+	http_requests{group="production", instance="0", job="api-server"} 100
+	http_requests{group="production", instance="1", job="api-server"} 200
+	http_requests{group="canary", instance="1", job="api-server"} 400
+	http_requests{group="canary", instance="0", job="api-server"} 300
+`,
+			expectedError: `error in eval sort(http_requests) (line 8): expected metric {__name__="http_requests", group="canary", instance="0", job="api-server"} with [300.000000] at position 4 but was at 3`,
+		},
+		"instant query with results expected to match provided order, but result has an unexpected series": {
+			input: testData + `
+eval_ordered instant at 50m sort(http_requests)
+	http_requests{group="production", instance="0", job="api-server"} 100
+	http_requests{group="production", instance="1", job="api-server"} 200
+	http_requests{group="canary", instance="0", job="api-server"} 300
+`,
+			expectedError: `error in eval sort(http_requests) (line 8): unexpected metric {__name__="http_requests", group="canary", instance="1", job="api-server"} in result`,
+		},
+		"instant query with invalid timestamp": {
+			input:         `eval instant at abc123 vector(0)`,
+			expectedError: `error in eval vector(0) (line 1): invalid timestamp definition "abc123": not a valid duration string: "abc123"`,
+		},
+		"range query with expected result": {
+			input: testData + `
+eval range from 0 to 10m step 5m sum by (group) (http_requests)
+	{group="production"} 0 30 60
+	{group="canary"} 0 70 140
+`,
+		},
+		"range query with unexpected float value": {
+			input: testData + `
+eval range from 0 to 10m step 5m sum by (group) (http_requests)
+	{group="production"} 0 30 60
+	{group="canary"} 0 80 140
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected float value at index 1 (t=300000) for {group="canary"} to be 80, but got 70 (result has 3 float points [0 @[0] 70 @[300000] 140 @[600000]] and 0 histogram points [])`,
+		},
+		"range query with expected histogram values": {
+			input: `
+load 5m
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}} {{schema:-1 sum:5 count:1 buckets:[1] offset:1}} {{schema:-1 sum:6 count:1 buckets:[1] offset:1}}
+
+eval range from 0 to 10m step 5m testmetric
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}} {{schema:-1 sum:5 count:1 buckets:[1] offset:1}} {{schema:-1 sum:6 count:1 buckets:[1] offset:1}}
+`,
+		},
+		"range query with unexpected histogram value": {
+			input: `
+load 5m
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}} {{schema:-1 sum:5 count:1 buckets:[1] offset:1}} {{schema:-1 sum:6 count:1 buckets:[1] offset:1}}
+
+eval range from 0 to 10m step 5m testmetric
+	testmetric {{schema:-1 sum:4 count:1 buckets:[1] offset:1}} {{schema:-1 sum:7 count:1 buckets:[1] offset:1}} {{schema:-1 sum:8 count:1 buckets:[1] offset:1}}
+`,
+			expectedError: `error in eval testmetric (line 5): expected histogram value at index 1 (t=300000) for {__name__="testmetric"} to be {count:1, sum:7, (1,4]:1}, but got {count:1, sum:5, (1,4]:1} (result has 0 float points [] and 3 histogram points [{count:1, sum:4, (1,4]:1} @[0] {count:1, sum:5, (1,4]:1} @[300000] {count:1, sum:6, (1,4]:1} @[600000]])`,
+		},
+		"range query with too many points for query time range": {
+			input: testData + `
+eval range from 0 to 10m step 5m sum by (group) (http_requests)
+	{group="production"} 0 30 60 90
+	{group="canary"} 0 70 140
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected 4 points for {group="production"}, but query time range cannot return this many points`,
+		},
+		"range query with missing point in result": {
+			input: `
+load 5m
+	testmetric 5
+
+eval range from 0 to 6m step 6m testmetric
+	testmetric 5 10
+`,
+			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 1 float point [5 @[0]] and 0 histogram points []`,
+		},
+		"range query with extra point in result": {
+			input: testData + `
+eval range from 0 to 10m step 5m sum by (group) (http_requests)
+	{group="production"} 0 30
+	{group="canary"} 0 70 140
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected 2 float points and 0 histogram points for {group="production"}, but got 3 float points [0 @[0] 30 @[300000] 60 @[600000]] and 0 histogram points []`,
+		},
+		"range query, but result has an unexpected series": {
+			input: testData + `
+eval range from 0 to 10m step 5m sum by (group) (http_requests)
+	{group="production"} 0 30 60
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): unexpected metric {group="canary"} in result`,
+		},
+		"range query, but result is missing a series": {
+			input: testData + `
+eval range from 0 to 10m step 5m sum by (group) (http_requests)
+	{group="production"} 0 30 60
+	{group="canary"} 0 70 140
+	{group="test"} 0 100 200
+`,
+			expectedError: `error in eval sum by (group) (http_requests) (line 8): expected metric {group="test"} not found`,
+		},
+		"range query expected to fail, and query fails": {
+			input: `
+load 5m
+	testmetric1{src="a",dst="b"} 0
+	testmetric2{src="a",dst="b"} 1
+
+eval_fail range from 0 to 10m step 5m ceil({__name__=~'testmetric1|testmetric2'})
+`,
+		},
+		"range query expected to fail, but query succeeds": {
+			input:         `eval_fail range from 0 to 10m step 5m vector(0)`,
+			expectedError: `expected error evaluating query "vector(0)" (line 1) but got none`,
+		},
+		"range query with from and to timestamps in wrong order": {
+			input:         `eval range from 10m to 9m step 5m vector(0)`,
+			expectedError: `error in eval vector(0) (line 1): invalid test definition, end timestamp (9m) is before start timestamp (10m)`,
+		},
+		"range query with sparse output": {
+			input: `
+load 6m
+	testmetric 1 _ 3
+
+eval range from 0 to 18m step 6m testmetric
+	testmetric 1 _ 3
+`,
+		},
+		"range query with float value returned when no value expected": {
+			input: `
+load 6m
+	testmetric 1 2 3
+
+eval range from 0 to 18m step 6m testmetric
+	testmetric 1 _ 3
+`,
+			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 3 float points [1 @[0] 2 @[360000] 3 @[720000]] and 0 histogram points []`,
+		},
+		"range query with float value returned when histogram expected": {
+			input: `
+load 5m
+	testmetric 2 3
+
+eval range from 0 to 5m step 5m testmetric
+	testmetric {{}} {{}}
+`,
+			expectedError: `error in eval testmetric (line 5): expected 0 float points and 2 histogram points for {__name__="testmetric"}, but got 2 float points [2 @[0] 3 @[300000]] and 0 histogram points []`,
+		},
+		"range query with histogram returned when float expected": {
+			input: `
+load 5m
+	testmetric {{}} {{}}
+
+eval range from 0 to 5m step 5m testmetric
+	testmetric 2 3
+`,
+			expectedError: `error in eval testmetric (line 5): expected 2 float points and 0 histogram points for {__name__="testmetric"}, but got 0 float points [] and 2 histogram points [{count:0, sum:0} @[0] {count:0, sum:0} @[300000]]`,
+		},
+		"range query with expected mixed results": {
+			input: `
+load 6m
+	testmetric{group="a"} {{}} _ _
+	testmetric{group="b"} _ _ 3
+
+eval range from 0 to 12m step 6m sum(testmetric)
+	{} {{}} _ 3
+`,
+		},
+		"range query with mixed results and incorrect values": {
+			input: `
+load 5m
+	testmetric 3 {{}}
+
+eval range from 0 to 5m step 5m testmetric
+	testmetric {{}} 3
+`,
+			expectedError: `error in eval testmetric (line 5): expected float value at index 0 for {__name__="testmetric"} to have timestamp 300000, but it had timestamp 0 (result has 1 float point [3 @[0]] and 1 histogram point [{count:0, sum:0} @[300000]])`,
+		},
+	}
+
+	for name, testCase := range testCases {
+		t.Run(name, func(t *testing.T) {
+			err := runTest(t, testCase.input, newTestEngine())
+
+			if testCase.expectedError == "" {
+				require.NoError(t, err)
+			} else {
+				require.EqualError(t, err, testCase.expectedError)
+			}
+		})
+	}
+}
+
+func TestAssertMatrixSorted(t *testing.T) {
+	testCases := map[string]struct {
+		matrix        Matrix
+		expectedError string
+	}{
+		"empty matrix": {
+			matrix: Matrix{},
+		},
+		"matrix with one series": {
+			matrix: Matrix{
+				Series{Metric: labels.FromStrings("the_label", "value_1")},
+			},
+		},
+		"matrix with two series, series in sorted order": {
+			matrix: Matrix{
+				Series{Metric: labels.FromStrings("the_label", "value_1")},
+				Series{Metric: labels.FromStrings("the_label", "value_2")},
+			},
+		},
+		"matrix with two series, series in reverse order": {
+			matrix: Matrix{
+				Series{Metric: labels.FromStrings("the_label", "value_2")},
+				Series{Metric: labels.FromStrings("the_label", "value_1")},
+			},
+			expectedError: `matrix results should always be sorted by labels, but matrix is not sorted: series at index 1 with labels {the_label="value_1"} sorts before series at index 0 with labels {the_label="value_2"}`,
+		},
+		"matrix with three series, series in sorted order": {
+			matrix: Matrix{
+				Series{Metric: labels.FromStrings("the_label", "value_1")},
+				Series{Metric: labels.FromStrings("the_label", "value_2")},
+				Series{Metric: labels.FromStrings("the_label", "value_3")},
+			},
+		},
+		"matrix with three series, series not in sorted order": {
+			matrix: Matrix{
+				Series{Metric: labels.FromStrings("the_label", "value_1")},
+				Series{Metric: labels.FromStrings("the_label", "value_3")},
+				Series{Metric: labels.FromStrings("the_label", "value_2")},
+			},
+			expectedError: `matrix results should always be sorted by labels, but matrix is not sorted: series at index 2 with labels {the_label="value_2"} sorts before series at index 1 with labels {the_label="value_3"}`,
+		},
+	}
+
+	for name, testCase := range testCases {
+		t.Run(name, func(t *testing.T) {
+			err := assertMatrixSorted(testCase.matrix)
+
+			if testCase.expectedError == "" {
+				require.NoError(t, err)
+			} else {
+				require.EqualError(t, err, testCase.expectedError)
+			}
+		})
+	}
+}

scrape/scrape.go

@@ -427,6 +427,7 @@ func (sp *scrapePool) sync(targets []*Target) {
 		bodySizeLimit = int64(sp.config.BodySizeLimit)
 		sampleLimit   = int(sp.config.SampleLimit)
 		bucketLimit   = int(sp.config.NativeHistogramBucketLimit)
+		maxSchema     = pickSchema(sp.config.NativeHistogramMinBucketFactor)
 		labelLimits   = &labelLimits{
 			labelLimit:            int(sp.config.LabelLimit),
 			labelNameLengthLimit:  int(sp.config.LabelNameLengthLimit),
@@ -464,6 +465,7 @@ func (sp *scrapePool) sync(targets []*Target) {
 				scraper:                  s,
 				sampleLimit:              sampleLimit,
 				bucketLimit:              bucketLimit,
+				maxSchema:                maxSchema,
 				labelLimits:              labelLimits,
 				honorLabels:              honorLabels,
 				honorTimestamps:          honorTimestamps,

scrape/scrape_test.go

@@ -41,6 +41,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/prometheus/config"
+	"github.com/prometheus/prometheus/discovery"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 	"github.com/prometheus/prometheus/model/exemplar"
 	"github.com/prometheus/prometheus/model/histogram"
@@ -3631,3 +3632,137 @@ func TestScrapeLoopSeriesAddedDuplicates(t *testing.T) {
 	value := metric.GetCounter().GetValue()
 	require.Equal(t, 4.0, value)
 }
+
+// This tests running a full scrape loop and checking that the scrape option
+// `native_histogram_min_bucket_factor` is used correctly.
+func TestNativeHistogramMaxSchemaSet(t *testing.T) {
+	testcases := map[string]struct {
+		minBucketFactor string
+		expectedSchema  int32
+	}{
+		"min factor not specified": {
+			minBucketFactor: "",
+			expectedSchema:  3, // Factor 1.09.
+		},
+		"min factor 1": {
+			minBucketFactor: "native_histogram_min_bucket_factor: 1",
+			expectedSchema:  3, // Factor 1.09.
+		},
+		"min factor 2": {
+			minBucketFactor: "native_histogram_min_bucket_factor: 2",
+			expectedSchema:  0, // Factor 2.00.
+		},
+	}
+	for name, tc := range testcases {
+		t.Run(name, func(t *testing.T) {
+			testNativeHistogramMaxSchemaSet(t, tc.minBucketFactor, tc.expectedSchema)
+		})
+	}
+}
+
+func testNativeHistogramMaxSchemaSet(t *testing.T, minBucketFactor string, expectedSchema int32) {
+	// Create a ProtoBuf message to serve as a Prometheus metric.
+	nativeHistogram := prometheus.NewHistogram(
+		prometheus.HistogramOpts{
+			Namespace:                      "testing",
+			Name:                           "example_native_histogram",
+			Help:                           "This is used for testing",
+			NativeHistogramBucketFactor:    1.1,
+			NativeHistogramMaxBucketNumber: 100,
+		},
+	)
+	registry := prometheus.NewRegistry()
+	registry.Register(nativeHistogram)
+	nativeHistogram.Observe(1.0)
+	nativeHistogram.Observe(1.0)
+	nativeHistogram.Observe(1.0)
+	nativeHistogram.Observe(10.0) // in different bucket since > 1*1.1.
+	nativeHistogram.Observe(10.0)
+
+	gathered, err := registry.Gather()
+	require.NoError(t, err)
+	require.NotEmpty(t, gathered)
+
+	histogramMetricFamily := gathered[0]
+	buffer := protoMarshalDelimited(t, histogramMetricFamily)
+
+	// Create a HTTP server to serve /metrics via ProtoBuf
+	metricsServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", `application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily; encoding=delimited`)
+		w.Write(buffer)
+	}))
+	defer metricsServer.Close()
+
+	// Create a scrape loop with the HTTP server as the target.
+	configStr := fmt.Sprintf(`
+global:
+  scrape_interval: 1s
+  scrape_timeout: 1s
+scrape_configs:
+  - job_name: test
+    %s
+    static_configs:
+      - targets: [%s]
+`, minBucketFactor, strings.ReplaceAll(metricsServer.URL, "http://", ""))
+
+	s := teststorage.New(t)
+	defer s.Close()
+	s.DB.EnableNativeHistograms()
+	reg := prometheus.NewRegistry()
+
+	mng, err := NewManager(nil, nil, s, reg)
+	require.NoError(t, err)
+	cfg, err := config.Load(configStr, false, log.NewNopLogger())
+	require.NoError(t, err)
+	mng.ApplyConfig(cfg)
+	tsets := make(chan map[string][]*targetgroup.Group)
+	go func() {
+		err = mng.Run(tsets)
+		require.NoError(t, err)
+	}()
+	defer mng.Stop()
+
+	// Get the static targets and apply them to the scrape manager.
+	require.Len(t, cfg.ScrapeConfigs, 1)
+	scrapeCfg := cfg.ScrapeConfigs[0]
+	require.Len(t, scrapeCfg.ServiceDiscoveryConfigs, 1)
+	staticDiscovery, ok := scrapeCfg.ServiceDiscoveryConfigs[0].(discovery.StaticConfig)
+	require.True(t, ok)
+	require.Len(t, staticDiscovery, 1)
+	tsets <- map[string][]*targetgroup.Group{"test": staticDiscovery}
+
+	// Wait for the scrape loop to scrape the target.
+	require.Eventually(t, func() bool {
+		q, err := s.Querier(0, math.MaxInt64)
+		require.NoError(t, err)
+		seriesS := q.Select(context.Background(), false, nil, labels.MustNewMatcher(labels.MatchEqual, "__name__", "testing_example_native_histogram"))
+		countSeries := 0
+		for seriesS.Next() {
+			countSeries++
+		}
+		return countSeries > 0
+	}, 15*time.Second, 100*time.Millisecond)
+
+	// Check that native histogram schema is as expected.
+	q, err := s.Querier(0, math.MaxInt64)
+	require.NoError(t, err)
+	seriesS := q.Select(context.Background(), false, nil, labels.MustNewMatcher(labels.MatchEqual, "__name__", "testing_example_native_histogram"))
+	histogramSamples := []*histogram.Histogram{}
+	for seriesS.Next() {
+		series := seriesS.At()
+		it := series.Iterator(nil)
+		for vt := it.Next(); vt != chunkenc.ValNone; vt = it.Next() {
+			if vt != chunkenc.ValHistogram {
+				// don't care about other samples
+				continue
+			}
+			_, h := it.AtHistogram(nil)
+			histogramSamples = append(histogramSamples, h)
+		}
+	}
+	require.NoError(t, seriesS.Err())
+	require.NotEmpty(t, histogramSamples)
+	for _, h := range histogramSamples {
+		require.Equal(t, expectedSchema, h.Schema)
+	}
+}

tsdb/db.go

@@ -529,9 +529,10 @@ func (db *DBReadOnly) loadDataAsQueryable(maxt int64) (storage.SampleAndChunkQue
 		if err := head.Init(maxBlockTime); err != nil {
 			return nil, fmt.Errorf("read WAL: %w", err)
 		}
-		// Set the wal to nil to disable all wal operations.
+		// Set the wal and the wbl to nil to disable related operations.
 		// This is mainly to avoid blocking when closing the head.
 		head.wal = nil
+		head.wbl = nil
 	}
 
 	db.closers = append(db.closers, head)
@@ -1608,7 +1609,7 @@ func BeyondTimeRetention(db *DB, blocks []*Block) (deletable map[ulid.ULID]struc
 
 	deletable = make(map[ulid.ULID]struct{})
 	for i, block := range blocks {
-		// The difference between the first block and this block is larger than
+		// The difference between the first block and this block is greater than or equal to
 		// the retention period so any blocks after that are added as deletable.
 		if i > 0 && blocks[0].Meta().MaxTime-block.Meta().MaxTime >= db.opts.RetentionDuration {
 			for _, b := range blocks[i:] {

tsdb/db_test.go

@@ -681,34 +681,6 @@ func TestDB_Snapshot(t *testing.T) {
 	require.Equal(t, 1000.0, sum)
 }
 
-func TestDB_BeyondTimeRetention(t *testing.T) {
-	opts := DefaultOptions()
-	opts.RetentionDuration = 100
-	db := openTestDB(t, opts, nil)
-	defer func() {
-		require.NoError(t, db.Close())
-	}()
-
-	// We have 4 blocks, 3 of which are beyond the retention duration.
-	metas := []BlockMeta{
-		{MinTime: 300, MaxTime: 500},
-		{MinTime: 200, MaxTime: 300},
-		{MinTime: 100, MaxTime: 200},
-		{MinTime: 0, MaxTime: 100},
-	}
-
-	for _, m := range metas {
-		createBlock(t, db.Dir(), genSeries(1, 1, m.MinTime, m.MaxTime))
-	}
-
-	// Reloading should truncate the 3 blocks which are >= the retention period.
-	require.NoError(t, db.reloadBlocks())
-	blocks := db.Blocks()
-	require.Len(t, blocks, 1)
-	require.Equal(t, metas[0].MinTime, blocks[0].Meta().MinTime)
-	require.Equal(t, metas[0].MaxTime, blocks[0].Meta().MaxTime)
-}
-
 // TestDB_Snapshot_ChunksOutsideOfCompactedRange ensures that a snapshot removes chunks samples
 // that are outside the set block time range.
 // See https://github.com/prometheus/prometheus/issues/5105
@@ -1491,34 +1463,66 @@ func (*mockCompactorFailing) CompactOOO(string, *OOOCompactionHead) (result []ul
 }
 
 func TestTimeRetention(t *testing.T) {
+	testCases := []struct {
+		name              string
+		blocks            []*BlockMeta
+		expBlocks         []*BlockMeta
+		retentionDuration int64
+	}{
+		{
+			name: "Block max time delta greater than retention duration",
+			blocks: []*BlockMeta{
+				{MinTime: 500, MaxTime: 900}, // Oldest block, beyond retention
+				{MinTime: 1000, MaxTime: 1500},
+				{MinTime: 1500, MaxTime: 2000}, // Newest block
+			},
+			expBlocks: []*BlockMeta{
+				{MinTime: 1000, MaxTime: 1500},
+				{MinTime: 1500, MaxTime: 2000},
+			},
+			retentionDuration: 1000,
+		},
+		{
+			name: "Block max time delta equal to retention duration",
+			blocks: []*BlockMeta{
+				{MinTime: 500, MaxTime: 900},   // Oldest block
+				{MinTime: 1000, MaxTime: 1500}, // Coinciding exactly with the retention duration.
+				{MinTime: 1500, MaxTime: 2000}, // Newest block
+			},
+			expBlocks: []*BlockMeta{
+				{MinTime: 1500, MaxTime: 2000},
+			},
+			retentionDuration: 500,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
 			db := openTestDB(t, nil, []int64{1000})
 			defer func() {
 				require.NoError(t, db.Close())
 			}()
 
-	blocks := []*BlockMeta{
-		{MinTime: 500, MaxTime: 900}, // Oldest block
-		{MinTime: 1000, MaxTime: 1500},
-		{MinTime: 1500, MaxTime: 2000}, // Newest Block
-	}
-
-	for _, m := range blocks {
+			for _, m := range tc.blocks {
 				createBlock(t, db.Dir(), genSeries(10, 10, m.MinTime, m.MaxTime))
 			}
 
 			require.NoError(t, db.reloadBlocks())       // Reload the db to register the new blocks.
-	require.Equal(t, len(blocks), len(db.Blocks())) // Ensure all blocks are registered.
+			require.Len(t, db.Blocks(), len(tc.blocks)) // Ensure all blocks are registered.
 
-	db.opts.RetentionDuration = blocks[2].MaxTime - blocks[1].MinTime
+			db.opts.RetentionDuration = tc.retentionDuration
+			// Reloading should truncate the blocks which are >= the retention duration vs the first block.
 			require.NoError(t, db.reloadBlocks())
 
-	expBlocks := blocks[1:]
 			actBlocks := db.Blocks()
 
 			require.Equal(t, 1, int(prom_testutil.ToFloat64(db.metrics.timeRetentionCount)), "metric retention count mismatch")
-	require.Equal(t, len(expBlocks), len(actBlocks))
-	require.Equal(t, expBlocks[0].MaxTime, actBlocks[0].meta.MaxTime)
-	require.Equal(t, expBlocks[len(expBlocks)-1].MaxTime, actBlocks[len(actBlocks)-1].meta.MaxTime)
+			require.Len(t, actBlocks, len(tc.expBlocks))
+			for i, eb := range tc.expBlocks {
+				require.Equal(t, eb.MinTime, actBlocks[i].meta.MinTime)
+				require.Equal(t, eb.MaxTime, actBlocks[i].meta.MaxTime)
+			}
+		})
+	}
 }
 
 func TestRetentionDurationMetric(t *testing.T) {
@@ -1994,6 +1998,7 @@ func TestInitializeHeadTimestamp(t *testing.T) {
 		// Should be set to init values if no WAL or blocks exist so far.
 		require.Equal(t, int64(math.MaxInt64), db.head.MinTime())
 		require.Equal(t, int64(math.MinInt64), db.head.MaxTime())
+		require.False(t, db.head.initialized())
 
 		// First added sample initializes the writable range.
 		ctx := context.Background()
@@ -2003,6 +2008,7 @@ func TestInitializeHeadTimestamp(t *testing.T) {
 
 		require.Equal(t, int64(1000), db.head.MinTime())
 		require.Equal(t, int64(1000), db.head.MaxTime())
+		require.True(t, db.head.initialized())
 	})
 	t.Run("wal-only", func(t *testing.T) {
 		dir := t.TempDir()
@@ -2031,6 +2037,7 @@ func TestInitializeHeadTimestamp(t *testing.T) {
 
 		require.Equal(t, int64(5000), db.head.MinTime())
 		require.Equal(t, int64(15000), db.head.MaxTime())
+		require.True(t, db.head.initialized())
 	})
 	t.Run("existing-block", func(t *testing.T) {
 		dir := t.TempDir()
@@ -2043,6 +2050,7 @@ func TestInitializeHeadTimestamp(t *testing.T) {
 
 		require.Equal(t, int64(2000), db.head.MinTime())
 		require.Equal(t, int64(2000), db.head.MaxTime())
+		require.True(t, db.head.initialized())
 	})
 	t.Run("existing-block-and-wal", func(t *testing.T) {
 		dir := t.TempDir()
@@ -2075,6 +2083,7 @@ func TestInitializeHeadTimestamp(t *testing.T) {
 
 		require.Equal(t, int64(6000), db.head.MinTime())
 		require.Equal(t, int64(15000), db.head.MaxTime())
+		require.True(t, db.head.initialized())
 		// Check that old series has been GCed.
 		require.Equal(t, 1.0, prom_testutil.ToFloat64(db.head.metrics.series))
 	})

tsdb/head.go

@@ -620,6 +620,7 @@ func (h *Head) Init(minValidTime int64) error {
 	refSeries := make(map[chunks.HeadSeriesRef]*memSeries)
 
 	snapshotLoaded := false
+	var chunkSnapshotLoadDuration time.Duration
 	if h.opts.EnableMemorySnapshotOnShutdown {
 		level.Info(h.logger).Log("msg", "Chunk snapshot is enabled, replaying from the snapshot")
 		// If there are any WAL files, there should be at least one WAL file with an index that is current or newer
@@ -650,7 +651,8 @@ func (h *Head) Init(minValidTime int64) error {
 			snapIdx, snapOffset, refSeries, err = h.loadChunkSnapshot()
 			if err == nil {
 				snapshotLoaded = true
-				level.Info(h.logger).Log("msg", "Chunk snapshot loading time", "duration", time.Since(start).String())
+				chunkSnapshotLoadDuration = time.Since(start)
+				level.Info(h.logger).Log("msg", "Chunk snapshot loading time", "duration", chunkSnapshotLoadDuration.String())
 			}
 			if err != nil {
 				snapIdx, snapOffset = -1, 0
@@ -672,6 +674,8 @@ func (h *Head) Init(minValidTime int64) error {
 		oooMmappedChunks map[chunks.HeadSeriesRef][]*mmappedChunk
 		lastMmapRef      chunks.ChunkDiskMapperRef
 		err              error
+
+		mmapChunkReplayDuration time.Duration
 	)
 	if snapshotLoaded || h.wal != nil {
 		// If snapshot was not loaded and if there is no WAL, then m-map chunks will be discarded
@@ -695,7 +699,8 @@ func (h *Head) Init(minValidTime int64) error {
 				return err
 			}
 		}
-		level.Info(h.logger).Log("msg", "On-disk memory mappable chunks replay completed", "duration", time.Since(mmapChunkReplayStart).String())
+		mmapChunkReplayDuration = time.Since(mmapChunkReplayStart)
+		level.Info(h.logger).Log("msg", "On-disk memory mappable chunks replay completed", "duration", mmapChunkReplayDuration.String())
 	}
 
 	if h.wal == nil {
@@ -817,6 +822,8 @@ func (h *Head) Init(minValidTime int64) error {
 		"checkpoint_replay_duration", checkpointReplayDuration.String(),
 		"wal_replay_duration", walReplayDuration.String(),
 		"wbl_replay_duration", wblReplayDuration.String(),
+		"chunk_snapshot_load_duration", chunkSnapshotLoadDuration.String(),
+		"mmap_chunk_replay_duration", mmapChunkReplayDuration.String(),
 		"total_replay_duration", totalReplayDuration.String(),
 	)
 
@@ -1074,11 +1081,11 @@ func (h *Head) SetMinValidTime(minValidTime int64) {
 
 // Truncate removes old data before mint from the head and WAL.
 func (h *Head) Truncate(mint int64) (err error) {
-	initialize := h.MinTime() == math.MaxInt64
+	initialized := h.initialized()
 	if err := h.truncateMemory(mint); err != nil {
 		return err
 	}
-	if initialize {
+	if !initialized {
 		return nil
 	}
 	return h.truncateWAL(mint)
@@ -1100,9 +1107,9 @@ func (h *Head) truncateMemory(mint int64) (err error) {
 		}
 	}()
 
-	initialize := h.MinTime() == math.MaxInt64
+	initialized := h.initialized()
 
-	if h.MinTime() >= mint && !initialize {
+	if h.MinTime() >= mint && initialized {
 		return nil
 	}
 
@@ -1113,7 +1120,7 @@ func (h *Head) truncateMemory(mint int64) (err error) {
 	defer h.memTruncationInProcess.Store(false)
 
 	// We wait for pending queries to end that overlap with this truncation.
-	if !initialize {
+	if initialized {
 		h.WaitForPendingReadersInTimeRange(h.MinTime(), mint)
 	}
 
@@ -1127,7 +1134,7 @@ func (h *Head) truncateMemory(mint int64) (err error) {
 
 	// This was an initial call to Truncate after loading blocks on startup.
 	// We haven't read back the WAL yet, so do not attempt to truncate it.
-	if initialize {
+	if !initialized {
 		return nil
 	}
 
@@ -1615,10 +1622,19 @@ func (h *Head) MaxOOOTime() int64 {
 	return h.maxOOOTime.Load()
 }
 
+// initialized returns true if the head has a MinTime set, false otherwise.
+func (h *Head) initialized() bool {
+	return h.MinTime() != math.MaxInt64
+}
+
 // compactable returns whether the head has a compactable range.
 // The head has a compactable range when the head time range is 1.5 times the chunk range.
 // The 0.5 acts as a buffer of the appendable window.
 func (h *Head) compactable() bool {
+	if !h.initialized() {
+		return false
+	}
+
 	return h.MaxTime()-h.MinTime() > h.chunkRange.Load()/2*3
 }
 

tsdb/head_append.go

@@ -138,7 +138,7 @@ func (h *Head) Appender(_ context.Context) storage.Appender {
 
 	// The head cache might not have a starting point yet. The init appender
 	// picks up the first appended timestamp as the base.
-	if h.MinTime() == math.MaxInt64 {
+	if !h.initialized() {
 		return &initAppender{
 			head: h,
 		}
@@ -191,7 +191,7 @@ func (h *Head) appendableMinValidTime() int64 {
 // AppendableMinValidTime returns the minimum valid time for samples to be appended to the Head.
 // Returns false if Head hasn't been initialized yet and the minimum time isn't known yet.
 func (h *Head) AppendableMinValidTime() (int64, bool) {
-	if h.MinTime() == math.MaxInt64 {
+	if !h.initialized() {
 		return 0, false
 	}
 

tsdb/head_test.go

@@ -5819,3 +5819,16 @@ func TestHeadAppender_AppendCTZeroSample(t *testing.T) {
 		require.Equal(t, chunkenc.ValNone, it.Next())
 	}
 }
+
+func TestHeadCompactableDoesNotCompactEmptyHead(t *testing.T) {
+	// Use a chunk range of 1 here so that if we attempted to determine if the head
+	// was compactable using default values for min and max times, `Head.compactable()`
+	// would return true which is incorrect. This test verifies that we short-circuit
+	// the check when the head has not yet had any samples added.
+	head, _ := newTestHead(t, 1, wlog.CompressionNone, false)
+	defer func() {
+		require.NoError(t, head.Close())
+	}()
+
+	require.False(t, head.compactable())
+}

tsdb/querier.go

@@ -19,8 +19,6 @@ import (
 	"fmt"
 	"math"
 	"slices"
-	"strings"
-	"unicode/utf8"
 
 	"github.com/oklog/ulid"
 
@@ -35,20 +33,6 @@ import (
 	"github.com/prometheus/prometheus/util/annotations"
 )
 
-// Bitmap used by func isRegexMetaCharacter to check whether a character needs to be escaped.
-var regexMetaCharacterBytes [16]byte
-
-// isRegexMetaCharacter reports whether byte b needs to be escaped.
-func isRegexMetaCharacter(b byte) bool {
-	return b < utf8.RuneSelf && regexMetaCharacterBytes[b%16]&(1<<(b/16)) != 0
-}
-
-func init() {
-	for _, b := range []byte(`.+*?()|[]{}^$`) {
-		regexMetaCharacterBytes[b%16] |= 1 << (b / 16)
-	}
-}
-
 type blockBaseQuerier struct {
 	blockID    ulid.ULID
 	index      IndexReader
@@ -195,55 +179,6 @@ func (q *blockChunkQuerier) Select(ctx context.Context, sortSeries bool, hints *
 	return NewBlockChunkSeriesSet(q.blockID, q.index, q.chunks, q.tombstones, p, mint, maxt, disableTrimming)
 }
 
-func findSetMatches(pattern string) []string {
-	// Return empty matches if the wrapper from Prometheus is missing.
-	if len(pattern) < 6 || pattern[:4] != "^(?:" || pattern[len(pattern)-2:] != ")$" {
-		return nil
-	}
-	escaped := false
-	sets := []*strings.Builder{{}}
-	init := 4
-	end := len(pattern) - 2
-	// If the regex is wrapped in a group we can remove the first and last parentheses
-	if pattern[init] == '(' && pattern[end-1] == ')' {
-		init++
-		end--
-	}
-	for i := init; i < end; i++ {
-		if escaped {
-			switch {
-			case isRegexMetaCharacter(pattern[i]):
-				sets[len(sets)-1].WriteByte(pattern[i])
-			case pattern[i] == '\\':
-				sets[len(sets)-1].WriteByte('\\')
-			default:
-				return nil
-			}
-			escaped = false
-		} else {
-			switch {
-			case isRegexMetaCharacter(pattern[i]):
-				if pattern[i] == '|' {
-					sets = append(sets, &strings.Builder{})
-				} else {
-					return nil
-				}
-			case pattern[i] == '\\':
-				escaped = true
-			default:
-				sets[len(sets)-1].WriteByte(pattern[i])
-			}
-		}
-	}
-	matches := make([]string, 0, len(sets))
-	for _, s := range sets {
-		if s.Len() > 0 {
-			matches = append(matches, s.String())
-		}
-	}
-	return matches
-}
-
 // PostingsForMatchers assembles a single postings iterator against the index reader
 // based on the given matchers. The resulting postings are not ordered by series.
 func PostingsForMatchers(ctx context.Context, ix IndexReader, ms ...*labels.Matcher) (index.Postings, error) {
@@ -385,7 +320,7 @@ func postingsForMatcher(ctx context.Context, ix IndexReader, m *labels.Matcher)
 
 	// Fast-path for set matching.
 	if m.Type == labels.MatchRegexp {
-		setMatches := findSetMatches(m.GetRegexString())
+		setMatches := m.SetMatches()
 		if len(setMatches) > 0 {
 			return ix.Postings(ctx, m.Name, setMatches...)
 		}
@@ -416,7 +351,7 @@ func inversePostingsForMatcher(ctx context.Context, ix IndexReader, m *labels.Ma
 	// Inverse of a MatchNotRegexp is MatchRegexp (double negation).
 	// Fast-path for set matching.
 	if m.Type == labels.MatchNotRegexp {
-		setMatches := findSetMatches(m.GetRegexString())
+		setMatches := m.SetMatches()
 		if len(setMatches) > 0 {
 			return ix.Postings(ctx, m.Name, setMatches...)
 		}

tsdb/querier_test.go

@@ -2658,54 +2658,6 @@ func BenchmarkSetMatcher(b *testing.B) {
 	}
 }
 
-// Refer to https://github.com/prometheus/prometheus/issues/2651.
-func TestFindSetMatches(t *testing.T) {
-	cases := []struct {
-		pattern string
-		exp     []string
-	}{
-		// Single value, coming from a `bar=~"foo"` selector.
-		{
-			pattern: "^(?:foo)$",
-			exp: []string{
-				"foo",
-			},
-		},
-		// Simple sets.
-		{
-			pattern: "^(?:foo|bar|baz)$",
-			exp: []string{
-				"foo",
-				"bar",
-				"baz",
-			},
-		},
-		// Simple sets containing escaped characters.
-		{
-			pattern: "^(?:fo\\.o|bar\\?|\\^baz)$",
-			exp: []string{
-				"fo.o",
-				"bar?",
-				"^baz",
-			},
-		},
-		// Simple sets containing special characters without escaping.
-		{
-			pattern: "^(?:fo.o|bar?|^baz)$",
-			exp:     nil,
-		},
-		// Missing wrapper.
-		{
-			pattern: "foo|bar|baz",
-			exp:     nil,
-		},
-	}
-
-	for _, c := range cases {
-		require.Equal(t, c.exp, findSetMatches(c.pattern), "Evaluating %s, unexpected result.", c.pattern)
-	}
-}
-
 func TestPostingsForMatchers(t *testing.T) {
 	ctx := context.Background()
 
@@ -3310,7 +3262,7 @@ func TestPostingsForMatcher(t *testing.T) {
 		{
 			// Test case for double quoted regex matcher
 			matcher:  labels.MustNewMatcher(labels.MatchRegexp, "test", "^(?:a|b)$"),
-			hasError: true,
+			hasError: false,
 		},
 	}
 

tsdb/wlog/checkpoint.go

@@ -152,6 +152,7 @@ func Checkpoint(logger log.Logger, w *WL, from, to int, keep func(id chunks.Head
 		series                []record.RefSeries
 		samples               []record.RefSample
 		histogramSamples      []record.RefHistogramSample
+		floatHistogramSamples []record.RefFloatHistogramSample
 		tstones               []tombstones.Stone
 		exemplars             []record.RefExemplar
 		metadata              []record.RefMetadata
@@ -164,7 +165,7 @@ func Checkpoint(logger log.Logger, w *WL, from, to int, keep func(id chunks.Head
 		latestMetadataMap = make(map[chunks.HeadSeriesRef]record.RefMetadata)
 	)
 	for r.Next() {
-		series, samples, histogramSamples, tstones, exemplars, metadata = series[:0], samples[:0], histogramSamples[:0], tstones[:0], exemplars[:0], metadata[:0]
+		series, samples, histogramSamples, floatHistogramSamples, tstones, exemplars, metadata = series[:0], samples[:0], histogramSamples[:0], floatHistogramSamples[:0], tstones[:0], exemplars[:0], metadata[:0]
 
 		// We don't reset the buffer since we batch up multiple records
 		// before writing them to the checkpoint.
@@ -224,8 +225,26 @@ func Checkpoint(logger log.Logger, w *WL, from, to int, keep func(id chunks.Head
 			if len(repl) > 0 {
 				buf = enc.HistogramSamples(repl, buf)
 			}
-			stats.TotalSamples += len(samples)
-			stats.DroppedSamples += len(samples) - len(repl)
+			stats.TotalSamples += len(histogramSamples)
+			stats.DroppedSamples += len(histogramSamples) - len(repl)
+
+		case record.FloatHistogramSamples:
+			floatHistogramSamples, err = dec.FloatHistogramSamples(rec, floatHistogramSamples)
+			if err != nil {
+				return nil, fmt.Errorf("decode float histogram samples: %w", err)
+			}
+			// Drop irrelevant floatHistogramSamples in place.
+			repl := floatHistogramSamples[:0]
+			for _, fh := range floatHistogramSamples {
+				if fh.T >= mint {
+					repl = append(repl, fh)
+				}
+			}
+			if len(repl) > 0 {
+				buf = enc.FloatHistogramSamples(repl, buf)
+			}
+			stats.TotalSamples += len(floatHistogramSamples)
+			stats.DroppedSamples += len(floatHistogramSamples) - len(repl)
 
 		case record.Tombstones:
 			tstones, err = dec.Tombstones(rec, tstones)

tsdb/wlog/checkpoint_test.go

@@ -125,6 +125,20 @@ func TestCheckpoint(t *testing.T) {
 			PositiveBuckets: []int64{int64(i + 1), 1, -1, 0},
 		}
 	}
+	makeFloatHistogram := func(i int) *histogram.FloatHistogram {
+		return &histogram.FloatHistogram{
+			Count:         5 + float64(i*4),
+			ZeroCount:     2 + float64(i),
+			ZeroThreshold: 0.001,
+			Sum:           18.4 * float64(i+1),
+			Schema:        1,
+			PositiveSpans: []histogram.Span{
+				{Offset: 0, Length: 2},
+				{Offset: 1, Length: 2},
+			},
+			PositiveBuckets: []float64{float64(i + 1), 1, -1, 0},
+		}
+	}
 
 	for _, compress := range []CompressionType{CompressionNone, CompressionSnappy, CompressionZstd} {
 		t.Run(fmt.Sprintf("compress=%s", compress), func(t *testing.T) {
@@ -154,7 +168,7 @@ func TestCheckpoint(t *testing.T) {
 			w, err = NewSize(nil, nil, dir, 64*1024, compress)
 			require.NoError(t, err)
 
-			samplesInWAL, histogramsInWAL := 0, 0
+			samplesInWAL, histogramsInWAL, floatHistogramsInWAL := 0, 0, 0
 			var last int64
 			for i := 0; ; i++ {
 				_, n, err := Segments(w.Dir())
@@ -200,6 +214,15 @@ func TestCheckpoint(t *testing.T) {
 				}, nil)
 				require.NoError(t, w.Log(b))
 				histogramsInWAL += 4
+				fh := makeFloatHistogram(i)
+				b = enc.FloatHistogramSamples([]record.RefFloatHistogramSample{
+					{Ref: 0, T: last, FH: fh},
+					{Ref: 1, T: last + 10000, FH: fh},
+					{Ref: 2, T: last + 20000, FH: fh},
+					{Ref: 3, T: last + 30000, FH: fh},
+				}, nil)
+				require.NoError(t, w.Log(b))
+				floatHistogramsInWAL += 4
 
 				b = enc.Exemplars([]record.RefExemplar{
 					{Ref: 1, T: last, V: float64(i), Labels: labels.FromStrings("trace_id", fmt.Sprintf("trace-%d", i))},
@@ -220,12 +243,14 @@ func TestCheckpoint(t *testing.T) {
 			}
 			require.NoError(t, w.Close())
 
-			_, err = Checkpoint(log.NewNopLogger(), w, 100, 106, func(x chunks.HeadSeriesRef) bool {
+			stats, err := Checkpoint(log.NewNopLogger(), w, 100, 106, func(x chunks.HeadSeriesRef) bool {
 				return x%2 == 0
 			}, last/2)
 			require.NoError(t, err)
 			require.NoError(t, w.Truncate(107))
 			require.NoError(t, DeleteCheckpoints(w.Dir(), 106))
+			require.Equal(t, histogramsInWAL+floatHistogramsInWAL+samplesInWAL, stats.TotalSamples)
+			require.Greater(t, stats.DroppedSamples, 0)
 
 			// Only the new checkpoint should be left.
 			files, err := os.ReadDir(dir)
@@ -242,7 +267,7 @@ func TestCheckpoint(t *testing.T) {
 			var metadata []record.RefMetadata
 			r := NewReader(sr)
 
-			samplesInCheckpoint, histogramsInCheckpoint := 0, 0
+			samplesInCheckpoint, histogramsInCheckpoint, floatHistogramsInCheckpoint := 0, 0, 0
 			for r.Next() {
 				rec := r.Record()
 
@@ -264,6 +289,13 @@ func TestCheckpoint(t *testing.T) {
 						require.GreaterOrEqual(t, h.T, last/2, "histogram with wrong timestamp")
 					}
 					histogramsInCheckpoint += len(histograms)
+				case record.FloatHistogramSamples:
+					floatHistograms, err := dec.FloatHistogramSamples(rec, nil)
+					require.NoError(t, err)
+					for _, h := range floatHistograms {
+						require.GreaterOrEqual(t, h.T, last/2, "float histogram with wrong timestamp")
+					}
+					floatHistogramsInCheckpoint += len(floatHistograms)
 				case record.Exemplars:
 					exemplars, err := dec.Exemplars(rec, nil)
 					require.NoError(t, err)
@@ -281,6 +313,8 @@ func TestCheckpoint(t *testing.T) {
 			require.Less(t, float64(samplesInCheckpoint)/float64(samplesInWAL), 0.8)
 			require.Greater(t, float64(histogramsInCheckpoint)/float64(histogramsInWAL), 0.5)
 			require.Less(t, float64(histogramsInCheckpoint)/float64(histogramsInWAL), 0.8)
+			require.Greater(t, float64(floatHistogramsInCheckpoint)/float64(floatHistogramsInWAL), 0.5)
+			require.Less(t, float64(floatHistogramsInCheckpoint)/float64(floatHistogramsInWAL), 0.8)
 
 			expectedRefSeries := []record.RefSeries{
 				{Ref: 0, Labels: labels.FromStrings("a", "b", "c", "0")},

util/teststorage/storage.go

@@ -14,6 +14,7 @@
 package teststorage
 
 import (
+	"fmt"
 	"os"
 	"time"
 
@@ -30,8 +31,18 @@ import (
 // New returns a new TestStorage for testing purposes
 // that removes all associated files on closing.
 func New(t testutil.T) *TestStorage {
+	stor, err := NewWithError()
+	require.NoError(t, err)
+	return stor
+}
+
+// NewWithError returns a new TestStorage for user facing tests, which reports
+// errors directly.
+func NewWithError() (*TestStorage, error) {
 	dir, err := os.MkdirTemp("", "test_storage")
-	require.NoError(t, err, "unexpected error while opening test directory")
+	if err != nil {
+		return nil, fmt.Errorf("opening test directory: %w", err)
+	}
 
 	// Tests just load data for a series sequentially. Thus we
 	// need a long appendable window.
@@ -41,13 +52,17 @@ func New(t testutil.T) *TestStorage {
 	opts.RetentionDuration = 0
 	opts.EnableNativeHistograms = true
 	db, err := tsdb.Open(dir, nil, nil, opts, tsdb.NewDBStats())
-	require.NoError(t, err, "unexpected error while opening test storage")
+	if err != nil {
+		return nil, fmt.Errorf("opening test storage: %w", err)
+	}
 	reg := prometheus.NewRegistry()
 	eMetrics := tsdb.NewExemplarMetrics(reg)
 
 	es, err := tsdb.NewCircularExemplarStorage(10, eMetrics)
-	require.NoError(t, err, "unexpected error while opening test exemplar storage")
-	return &TestStorage{DB: db, exemplarStorage: es, dir: dir}
+	if err != nil {
+		return nil, fmt.Errorf("opening test exemplar storage: %w", err)
+	}
+	return &TestStorage{DB: db, exemplarStorage: es, dir: dir}, nil
 }
 
 type TestStorage struct {