Merge remote-tracking branch 'prometheus/main' into arve/wlog-histograms

.gitpod.Dockerfile

@@ -1,15 +1,33 @@
 FROM gitpod/workspace-full
 
+# Set Node.js version as an environment variable.
 ENV CUSTOM_NODE_VERSION=16
-ENV CUSTOM_GO_VERSION=1.19
-ENV GOPATH=$HOME/go-packages
-ENV GOROOT=$HOME/go
-ENV PATH=$GOROOT/bin:$GOPATH/bin:$PATH
 
+# Install and use the specified Node.js version via nvm.
 RUN bash -c ". .nvm/nvm.sh && nvm install ${CUSTOM_NODE_VERSION} && nvm use ${CUSTOM_NODE_VERSION} && nvm alias default ${CUSTOM_NODE_VERSION}"
 
+# Ensure nvm uses the default Node.js version in all new shells.
 RUN echo "nvm use default &>/dev/null" >> ~/.bashrc.d/51-nvm-fix
-RUN curl -fsSL https://dl.google.com/go/go${GO_VERSION}.linux-amd64.tar.gz | tar xzs \
-    && printf '%s\n' 'export GOPATH=/workspace/go' \
-                      'export PATH=$GOPATH/bin:$PATH' > $HOME/.bashrc.d/300-go
 
+# Remove any existing Go installation in $HOME path.
+RUN rm -rf $HOME/go $HOME/go-packages
+
+# Export go environment variables.
+RUN echo "export GOPATH=/workspace/go" >> ~/.bashrc.d/300-go && \
+    echo "export GOBIN=\$GOPATH/bin" >> ~/.bashrc.d/300-go && \
+    echo "export GOROOT=${HOME}/go" >> ~/.bashrc.d/300-go && \
+    echo "export PATH=\$GOROOT/bin:\$GOBIN:\$PATH" >> ~/.bashrc
+
+# Reload the environment variables to ensure go environment variables are
+# available in subsequent commands.
+RUN bash -c "source ~/.bashrc && source ~/.bashrc.d/300-go"
+
+# Fetch the Go version dynamically from the Prometheus go.mod file and Install Go in $HOME path.
+RUN export CUSTOM_GO_VERSION=$(curl -sSL "https://raw.githubusercontent.com/prometheus/prometheus/main/go.mod" | awk '/^go/{print $2".0"}') && \
+    curl -fsSL "https://dl.google.com/go/go${CUSTOM_GO_VERSION}.linux-amd64.tar.gz" | \
+    tar -xz -C $HOME
+
+# Fetch the goyacc parser version dynamically from the Prometheus Makefile
+# and install it globally in $GOBIN path.
+RUN GOYACC_VERSION=$(curl -fsSL "https://raw.githubusercontent.com/prometheus/prometheus/main/Makefile" | awk -F'=' '/GOYACC_VERSION \?=/{gsub(/ /, "", $2); print $2}') && \
+    go install "golang.org/x/tools/cmd/goyacc@${GOYACC_VERSION}"

.golangci.yml

@@ -21,6 +21,7 @@ linters:
     - goimports
     - misspell
     - nolintlint
+    - perfsprint
     - predeclared
     - revive
     - testifylint
@@ -44,7 +45,9 @@ issues:
     - linters:
         - godot
       source: "^// ==="
-
+    - linters:
+        - perfsprint
+      text: "fmt.Sprintf can be replaced with string addition"
 linters-settings:
   depguard:
     rules:
@@ -85,6 +88,9 @@ linters-settings:
     local-prefixes: github.com/prometheus/prometheus
   gofumpt:
     extra-rules: true
+  perfsprint:
+     # Optimizes `fmt.Errorf`.
+    errorf: false
   revive:
     # By default, revive will enable only the linting rules that are named in the configuration file.
     # So, it's needed to explicitly set in configuration all required rules.

CONTRIBUTING.md

@@ -42,7 +42,12 @@ go build ./cmd/prometheus/
 make test         # Make sure all the tests pass before you commit and push :)
 ```
 
-We use [`golangci-lint`](https://github.com/golangci/golangci-lint) for linting the code. If it reports an issue and you think that the warning needs to be disregarded or is a false-positive, you can add a special comment `//nolint:linter1[,linter2,...]` before the offending line. Use this sparingly though, fixing the code to comply with the linter's recommendation is in general the preferred course of action.
+To run a collection of Go linters through [`golangci-lint`](https://github.com/golangci/golangci-lint), do:
+```bash
+make lint
+```
+
+If it reports an issue and you think that the warning needs to be disregarded or is a false-positive, you can add a special comment `//nolint:linter1[,linter2,...]` before the offending line. Use this sparingly though, fixing the code to comply with the linter's recommendation is in general the preferred course of action. See [this section of the golangci-lint documentation](https://golangci-lint.run/usage/false-positives/#nolint-directive) for more information.
 
 All our issues are regularly tagged so that you can also filter down the issues involving the components you want to work on. For our labeling policy refer [the wiki page](https://github.com/prometheus/prometheus/wiki/Label-Names-and-Descriptions).
 

cmd/prometheus/main.go

@@ -418,7 +418,7 @@ func main() {
 	serverOnlyFlag(a, "rules.alert.resend-delay", "Minimum amount of time to wait before resending an alert to Alertmanager.").
 		Default("1m").SetValue(&cfg.resendDelay)
 
-	serverOnlyFlag(a, "rules.max-concurrent-evals", "Global concurrency limit for independent rules that can run concurrently.").
+	serverOnlyFlag(a, "rules.max-concurrent-evals", "Global concurrency limit for independent rules that can run concurrently. When set, \"query.max-concurrency\" may need to be adjusted accordingly.").
 		Default("4").Int64Var(&cfg.maxConcurrentEvals)
 
 	a.Flag("scrape.adjust-timestamps", "Adjust scrape timestamps by up to `scrape.timestamp-tolerance` to align them to the intended schedule. See https://github.com/prometheus/prometheus/issues/7846 for more context. Experimental. This flag will be removed in a future release.").

cmd/prometheus/main_test.go

@@ -24,6 +24,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 	"syscall"
 	"testing"
@@ -189,7 +190,7 @@ func TestSendAlerts(t *testing.T) {
 
 	for i, tc := range testCases {
 		tc := tc
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			senderFunc := senderFunc(func(alerts ...*notifier.Alert) {
 				require.NotEmpty(t, tc.in, "sender called with 0 alert")
 				require.Equal(t, tc.exp, alerts)

cmd/promtool/backfill.go

@@ -88,7 +88,7 @@ func createBlocks(input []byte, mint, maxt, maxBlockDuration int64, maxSamplesIn
 	blockDuration := getCompatibleBlockDuration(maxBlockDuration)
 	mint = blockDuration * (mint / blockDuration)
 
-	db, err := tsdb.OpenDBReadOnly(outputDir, nil)
+	db, err := tsdb.OpenDBReadOnly(outputDir, "", nil)
 	if err != nil {
 		return err
 	}

cmd/promtool/main.go

@@ -235,12 +235,14 @@ func main() {
 
 	tsdbDumpCmd := tsdbCmd.Command("dump", "Dump samples from a TSDB.")
 	dumpPath := tsdbDumpCmd.Arg("db path", "Database path (default is "+defaultDBPath+").").Default(defaultDBPath).String()
+	dumpSandboxDirRoot := tsdbDumpCmd.Flag("sandbox-dir-root", "Root directory where a sandbox directory would be created in case WAL replay generates chunks. The sandbox directory is cleaned up at the end.").Default(defaultDBPath).String()
 	dumpMinTime := tsdbDumpCmd.Flag("min-time", "Minimum timestamp to dump.").Default(strconv.FormatInt(math.MinInt64, 10)).Int64()
 	dumpMaxTime := tsdbDumpCmd.Flag("max-time", "Maximum timestamp to dump.").Default(strconv.FormatInt(math.MaxInt64, 10)).Int64()
 	dumpMatch := tsdbDumpCmd.Flag("match", "Series selector. Can be specified multiple times.").Default("{__name__=~'(?s:.*)'}").Strings()
 
-	tsdbDumpOpenMetricsCmd := tsdbCmd.Command("dump-openmetrics", "[Experimental] Dump samples from a TSDB into OpenMetrics format. Native histograms are not dumped.")
+	tsdbDumpOpenMetricsCmd := tsdbCmd.Command("dump-openmetrics", "[Experimental] Dump samples from a TSDB into OpenMetrics text format, excluding native histograms and staleness markers, which are not representable in OpenMetrics.")
 	dumpOpenMetricsPath := tsdbDumpOpenMetricsCmd.Arg("db path", "Database path (default is "+defaultDBPath+").").Default(defaultDBPath).String()
+	dumpOpenMetricsSandboxDirRoot := tsdbDumpOpenMetricsCmd.Flag("sandbox-dir-root", "Root directory where a sandbox directory would be created in case WAL replay generates chunks. The sandbox directory is cleaned up at the end.").Default(defaultDBPath).String()
 	dumpOpenMetricsMinTime := tsdbDumpOpenMetricsCmd.Flag("min-time", "Minimum timestamp to dump.").Default(strconv.FormatInt(math.MinInt64, 10)).Int64()
 	dumpOpenMetricsMaxTime := tsdbDumpOpenMetricsCmd.Flag("max-time", "Maximum timestamp to dump.").Default(strconv.FormatInt(math.MaxInt64, 10)).Int64()
 	dumpOpenMetricsMatch := tsdbDumpOpenMetricsCmd.Flag("match", "Series selector. Can be specified multiple times.").Default("{__name__=~'(?s:.*)'}").Strings()
@@ -396,9 +398,9 @@ func main() {
 		os.Exit(checkErr(listBlocks(*listPath, *listHumanReadable)))
 
 	case tsdbDumpCmd.FullCommand():
-		os.Exit(checkErr(dumpSamples(ctx, *dumpPath, *dumpMinTime, *dumpMaxTime, *dumpMatch, formatSeriesSet)))
+		os.Exit(checkErr(dumpSamples(ctx, *dumpPath, *dumpSandboxDirRoot, *dumpMinTime, *dumpMaxTime, *dumpMatch, formatSeriesSet)))
 	case tsdbDumpOpenMetricsCmd.FullCommand():
-		os.Exit(checkErr(dumpSamples(ctx, *dumpOpenMetricsPath, *dumpOpenMetricsMinTime, *dumpOpenMetricsMaxTime, *dumpOpenMetricsMatch, formatSeriesSetOpenMetrics)))
+		os.Exit(checkErr(dumpSamples(ctx, *dumpOpenMetricsPath, *dumpOpenMetricsSandboxDirRoot, *dumpOpenMetricsMinTime, *dumpOpenMetricsMaxTime, *dumpOpenMetricsMatch, formatSeriesSetOpenMetrics)))
 	// TODO(aSquare14): Work on adding support for custom block size.
 	case openMetricsImportCmd.FullCommand():
 		os.Exit(backfillOpenMetrics(*importFilePath, *importDBPath, *importHumanReadable, *importQuiet, *maxBlockDuration))

cmd/promtool/main_test.go

@@ -25,6 +25,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"strconv"
 	"strings"
 	"syscall"
 	"testing"
@@ -410,7 +411,7 @@ func TestExitCodes(t *testing.T) {
 	} {
 		t.Run(c.file, func(t *testing.T) {
 			for _, lintFatal := range []bool{true, false} {
-				t.Run(fmt.Sprintf("%t", lintFatal), func(t *testing.T) {
+				t.Run(strconv.FormatBool(lintFatal), func(t *testing.T) {
 					args := []string{"-test.main", "check", "config", "testdata/" + c.file}
 					if lintFatal {
 						args = append(args, "--lint-fatal")

cmd/promtool/tsdb.go

@@ -338,7 +338,7 @@ func readPrometheusLabels(r io.Reader, n int) ([]labels.Labels, error) {
 }
 
 func listBlocks(path string, humanReadable bool) error {
-	db, err := tsdb.OpenDBReadOnly(path, nil)
+	db, err := tsdb.OpenDBReadOnly(path, "", nil)
 	if err != nil {
 		return err
 	}
@@ -393,7 +393,7 @@ func getFormatedBytes(bytes int64, humanReadable bool) string {
 }
 
 func openBlock(path, blockID string) (*tsdb.DBReadOnly, tsdb.BlockReader, error) {
-	db, err := tsdb.OpenDBReadOnly(path, nil)
+	db, err := tsdb.OpenDBReadOnly(path, "", nil)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -708,8 +708,8 @@ func analyzeCompaction(ctx context.Context, block tsdb.BlockReader, indexr tsdb.
 
 type SeriesSetFormatter func(series storage.SeriesSet) error
 
-func dumpSamples(ctx context.Context, path string, mint, maxt int64, match []string, formatter SeriesSetFormatter) (err error) {
+func dumpSamples(ctx context.Context, dbDir, sandboxDirRoot string, mint, maxt int64, match []string, formatter SeriesSetFormatter) (err error) {
-	db, err := tsdb.OpenDBReadOnly(path, nil)
+	db, err := tsdb.OpenDBReadOnly(dbDir, sandboxDirRoot, nil)
 	if err != nil {
 		return err
 	}
@@ -856,9 +856,9 @@ func displayHistogram(dataType string, datas []int, total int) {
 	}
 	avg := sum / len(datas)
 	fmt.Printf("%s (min/avg/max): %d/%d/%d\n", dataType, datas[0], avg, datas[len(datas)-1])
-	maxLeftLen := strconv.Itoa(len(fmt.Sprintf("%d", end)))
+	maxLeftLen := strconv.Itoa(len(strconv.Itoa(end)))
-	maxRightLen := strconv.Itoa(len(fmt.Sprintf("%d", end+step)))
+	maxRightLen := strconv.Itoa(len(strconv.Itoa(end + step)))
-	maxCountLen := strconv.Itoa(len(fmt.Sprintf("%d", maxCount)))
+	maxCountLen := strconv.Itoa(len(strconv.Itoa(maxCount)))
 	for bucket, count := range buckets {
 		percentage := 100.0 * count / total
 		fmt.Printf("[%"+maxLeftLen+"d, %"+maxRightLen+"d]: %"+maxCountLen+"d %s\n", bucket*step+start+1, (bucket+1)*step+start, count, strings.Repeat("#", percentage))

cmd/promtool/tsdb_test.go

@@ -64,6 +64,7 @@ func getDumpedSamples(t *testing.T, path string, mint, maxt int64, match []strin
 	err := dumpSamples(
 		context.Background(),
 		path,
+		t.TempDir(),
 		mint,
 		maxt,
 		match,

cmd/promtool/unittest.go

@@ -573,7 +573,7 @@ func (la labelsAndAnnotations) String() string {
 	}
 	s := "[\n0:" + indentLines("\n"+la[0].String(), "  ")
 	for i, l := range la[1:] {
-		s += ",\n" + fmt.Sprintf("%d", i+1) + ":" + indentLines("\n"+l.String(), "  ")
+		s += ",\n" + strconv.Itoa(i+1) + ":" + indentLines("\n"+l.String(), "  ")
 	}
 	s += "\n]"
 

discovery/aws/ec2.go

@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"time"
 
@@ -279,7 +280,7 @@ func (d *EC2Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error
 				if inst.PrivateDnsName != nil {
 					labels[ec2LabelPrivateDNS] = model.LabelValue(*inst.PrivateDnsName)
 				}
-				addr := net.JoinHostPort(*inst.PrivateIpAddress, fmt.Sprintf("%d", d.cfg.Port))
+				addr := net.JoinHostPort(*inst.PrivateIpAddress, strconv.Itoa(d.cfg.Port))
 				labels[model.AddressLabel] = model.LabelValue(addr)
 
 				if inst.Platform != nil {

discovery/aws/lightsail.go

@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"time"
 
@@ -229,7 +230,7 @@ func (d *LightsailDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group,
 			lightsailLabelRegion:              model.LabelValue(d.cfg.Region),
 		}
 
-		addr := net.JoinHostPort(*inst.PrivateIpAddress, fmt.Sprintf("%d", d.cfg.Port))
+		addr := net.JoinHostPort(*inst.PrivateIpAddress, strconv.Itoa(d.cfg.Port))
 		labels[model.AddressLabel] = model.LabelValue(addr)
 
 		if inst.PublicIpAddress != nil {

discovery/azure/azure.go

@@ -20,6 +20,7 @@ import (
 	"math/rand"
 	"net"
 	"net/http"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -492,7 +493,7 @@ func (d *Discovery) vmToLabelSet(ctx context.Context, client client, vm virtualM
 				}
 				if ip.Properties != nil && ip.Properties.PrivateIPAddress != nil {
 					labels[azureLabelMachinePrivateIP] = model.LabelValue(*ip.Properties.PrivateIPAddress)
-					address := net.JoinHostPort(*ip.Properties.PrivateIPAddress, fmt.Sprintf("%d", d.port))
+					address := net.JoinHostPort(*ip.Properties.PrivateIPAddress, strconv.Itoa(d.port))
 					labels[model.AddressLabel] = model.LabelValue(address)
 					return labels, nil
 				}

discovery/consul/consul.go

@@ -539,9 +539,9 @@ func (srv *consulService) watch(ctx context.Context, ch chan<- []*targetgroup.Gr
 		// since the service may be registered remotely through a different node.
 		var addr string
 		if serviceNode.Service.Address != "" {
-			addr = net.JoinHostPort(serviceNode.Service.Address, fmt.Sprintf("%d", serviceNode.Service.Port))
+			addr = net.JoinHostPort(serviceNode.Service.Address, strconv.Itoa(serviceNode.Service.Port))
 		} else {
-			addr = net.JoinHostPort(serviceNode.Node.Address, fmt.Sprintf("%d", serviceNode.Service.Port))
+			addr = net.JoinHostPort(serviceNode.Node.Address, strconv.Itoa(serviceNode.Service.Port))
 		}
 
 		labels := model.LabelSet{

discovery/digitalocean/digitalocean.go

@@ -177,7 +177,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 		}
 
 		labels := model.LabelSet{
-			doLabelID:          model.LabelValue(fmt.Sprintf("%d", droplet.ID)),
+			doLabelID:          model.LabelValue(strconv.Itoa(droplet.ID)),
 			doLabelName:        model.LabelValue(droplet.Name),
 			doLabelImage:       model.LabelValue(droplet.Image.Slug),
 			doLabelImageName:   model.LabelValue(droplet.Image.Name),

discovery/dns/dns.go

@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -200,7 +201,7 @@ func (d *Discovery) refreshOne(ctx context.Context, name string, ch chan<- *targ
 
 	tg := &targetgroup.Group{}
 	hostPort := func(a string, p int) model.LabelValue {
-		return model.LabelValue(net.JoinHostPort(a, fmt.Sprintf("%d", p)))
+		return model.LabelValue(net.JoinHostPort(a, strconv.Itoa(p)))
 	}
 
 	for _, record := range response.Answer {
@@ -209,7 +210,7 @@ func (d *Discovery) refreshOne(ctx context.Context, name string, ch chan<- *targ
 		switch addr := record.(type) {
 		case *dns.SRV:
 			dnsSrvRecordTarget = model.LabelValue(addr.Target)
-			dnsSrvRecordPort = model.LabelValue(fmt.Sprintf("%d", addr.Port))
+			dnsSrvRecordPort = model.LabelValue(strconv.Itoa(int(addr.Port)))
 
 			// Remove the final dot from rooted DNS names to make them look more usual.
 			addr.Target = strings.TrimRight(addr.Target, ".")

discovery/hetzner/hcloud.go

@@ -15,7 +15,6 @@ package hetzner
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"net/http"
 	"strconv"
@@ -92,7 +91,7 @@ func (d *hcloudDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group, er
 	for i, server := range servers {
 		labels := model.LabelSet{
 			hetznerLabelRole:              model.LabelValue(HetznerRoleHcloud),
-			hetznerLabelServerID:          model.LabelValue(fmt.Sprintf("%d", server.ID)),
+			hetznerLabelServerID:          model.LabelValue(strconv.FormatInt(server.ID, 10)),
 			hetznerLabelServerName:        model.LabelValue(server.Name),
 			hetznerLabelDatacenter:        model.LabelValue(server.Datacenter.Name),
 			hetznerLabelPublicIPv4:        model.LabelValue(server.PublicNet.IPv4.IP.String()),
@@ -102,10 +101,10 @@ func (d *hcloudDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group, er
 			hetznerLabelHcloudDatacenterLocation:            model.LabelValue(server.Datacenter.Location.Name),
 			hetznerLabelHcloudDatacenterLocationNetworkZone: model.LabelValue(server.Datacenter.Location.NetworkZone),
 			hetznerLabelHcloudType:                          model.LabelValue(server.ServerType.Name),
-			hetznerLabelHcloudCPUCores:                      model.LabelValue(fmt.Sprintf("%d", server.ServerType.Cores)),
+			hetznerLabelHcloudCPUCores:                      model.LabelValue(strconv.Itoa(server.ServerType.Cores)),
 			hetznerLabelHcloudCPUType:                       model.LabelValue(server.ServerType.CPUType),
-			hetznerLabelHcloudMemoryGB:                      model.LabelValue(fmt.Sprintf("%d", int(server.ServerType.Memory))),
+			hetznerLabelHcloudMemoryGB:                      model.LabelValue(strconv.Itoa(int(server.ServerType.Memory))),
-			hetznerLabelHcloudDiskGB:                        model.LabelValue(fmt.Sprintf("%d", server.ServerType.Disk)),
+			hetznerLabelHcloudDiskGB:                        model.LabelValue(strconv.Itoa(server.ServerType.Disk)),
 
 			model.AddressLabel: model.LabelValue(net.JoinHostPort(server.PublicNet.IPv4.IP.String(), strconv.FormatUint(uint64(d.port), 10))),
 		}

discovery/hetzner/robot.go

@@ -112,7 +112,7 @@ func (d *robotDiscovery) refresh(context.Context) ([]*targetgroup.Group, error)
 			hetznerLabelPublicIPv4:     model.LabelValue(server.Server.ServerIP),
 			hetznerLabelServerStatus:   model.LabelValue(server.Server.Status),
 			hetznerLabelRobotProduct:   model.LabelValue(server.Server.Product),
-			hetznerLabelRobotCancelled: model.LabelValue(fmt.Sprintf("%t", server.Server.Canceled)),
+			hetznerLabelRobotCancelled: model.LabelValue(strconv.FormatBool(server.Server.Canceled)),
 
 			model.AddressLabel: model.LabelValue(net.JoinHostPort(server.Server.ServerIP, strconv.FormatUint(uint64(d.port), 10))),
 		}

discovery/legacymanager/manager_test.go

@@ -720,7 +720,7 @@ func staticConfig(addrs ...string) discovery.StaticConfig {
 	var cfg discovery.StaticConfig
 	for i, addr := range addrs {
 		cfg = append(cfg, &targetgroup.Group{
-			Source: fmt.Sprint(i),
+			Source: strconv.Itoa(i),
 			Targets: []model.LabelSet{
 				{model.AddressLabel: model.LabelValue(addr)},
 			},

discovery/linode/linode.go

@@ -325,7 +325,7 @@ func (d *Discovery) refreshData(ctx context.Context) ([]*targetgroup.Group, erro
 		}
 
 		labels := model.LabelSet{
-			linodeLabelID:                 model.LabelValue(fmt.Sprintf("%d", instance.ID)),
+			linodeLabelID:                 model.LabelValue(strconv.Itoa(instance.ID)),
 			linodeLabelName:               model.LabelValue(instance.Label),
 			linodeLabelImage:              model.LabelValue(instance.Image),
 			linodeLabelPrivateIPv4:        model.LabelValue(privateIPv4),
@@ -338,13 +338,13 @@ func (d *Discovery) refreshData(ctx context.Context) ([]*targetgroup.Group, erro
 			linodeLabelType:               model.LabelValue(instance.Type),
 			linodeLabelStatus:             model.LabelValue(instance.Status),
 			linodeLabelGroup:              model.LabelValue(instance.Group),
-			linodeLabelGPUs:               model.LabelValue(fmt.Sprintf("%d", instance.Specs.GPUs)),
+			linodeLabelGPUs:               model.LabelValue(strconv.Itoa(instance.Specs.GPUs)),
 			linodeLabelHypervisor:         model.LabelValue(instance.Hypervisor),
 			linodeLabelBackups:            model.LabelValue(backupsStatus),
-			linodeLabelSpecsDiskBytes:     model.LabelValue(fmt.Sprintf("%d", int64(instance.Specs.Disk)<<20)),
+			linodeLabelSpecsDiskBytes:     model.LabelValue(strconv.FormatInt(int64(instance.Specs.Disk)<<20, 10)),
-			linodeLabelSpecsMemoryBytes:   model.LabelValue(fmt.Sprintf("%d", int64(instance.Specs.Memory)<<20)),
+			linodeLabelSpecsMemoryBytes:   model.LabelValue(strconv.FormatInt(int64(instance.Specs.Memory)<<20, 10)),
-			linodeLabelSpecsVCPUs:         model.LabelValue(fmt.Sprintf("%d", instance.Specs.VCPUs)),
+			linodeLabelSpecsVCPUs:         model.LabelValue(strconv.Itoa(instance.Specs.VCPUs)),
-			linodeLabelSpecsTransferBytes: model.LabelValue(fmt.Sprintf("%d", int64(instance.Specs.Transfer)<<20)),
+			linodeLabelSpecsTransferBytes: model.LabelValue(strconv.FormatInt(int64(instance.Specs.Transfer)<<20, 10)),
 		}
 
 		addr := net.JoinHostPort(publicIPv4, strconv.FormatUint(uint64(d.port), 10))

discovery/manager_test.go

@@ -720,7 +720,7 @@ func staticConfig(addrs ...string) StaticConfig {
 	var cfg StaticConfig
 	for i, addr := range addrs {
 		cfg = append(cfg, &targetgroup.Group{
-			Source: fmt.Sprint(i),
+			Source: strconv.Itoa(i),
 			Targets: []model.LabelSet{
 				{model.AddressLabel: model.LabelValue(addr)},
 			},

discovery/marathon/marathon.go

@@ -505,7 +505,7 @@ func targetEndpoint(task *task, port uint32, containerNet bool) string {
 		host = task.Host
 	}
 
-	return net.JoinHostPort(host, fmt.Sprintf("%d", port))
+	return net.JoinHostPort(host, strconv.Itoa(int(port)))
 }
 
 // Get a list of ports and a list of labels from a PortMapping.

discovery/moby/network.go

@@ -15,7 +15,7 @@ package moby
 
 import (
 	"context"
-	"fmt"
+	"strconv"
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
@@ -44,8 +44,8 @@ func getNetworksLabels(ctx context.Context, client *client.Client, labelPrefix s
 			labelPrefix + labelNetworkID:       network.ID,
 			labelPrefix + labelNetworkName:     network.Name,
 			labelPrefix + labelNetworkScope:    network.Scope,
-			labelPrefix + labelNetworkInternal: fmt.Sprintf("%t", network.Internal),
+			labelPrefix + labelNetworkInternal: strconv.FormatBool(network.Internal),
-			labelPrefix + labelNetworkIngress:  fmt.Sprintf("%t", network.Ingress),
+			labelPrefix + labelNetworkIngress:  strconv.FormatBool(network.Ingress),
 		}
 		for k, v := range network.Labels {
 			ln := strutil.SanitizeLabelName(k)

discovery/moby/nodes.go

@@ -66,7 +66,7 @@ func (d *Discovery) refreshNodes(ctx context.Context) ([]*targetgroup.Group, err
 			swarmLabelNodeAddress:              model.LabelValue(n.Status.Addr),
 		}
 		if n.ManagerStatus != nil {
-			labels[swarmLabelNodeManagerLeader] = model.LabelValue(fmt.Sprintf("%t", n.ManagerStatus.Leader))
+			labels[swarmLabelNodeManagerLeader] = model.LabelValue(strconv.FormatBool(n.ManagerStatus.Leader))
 			labels[swarmLabelNodeManagerReachability] = model.LabelValue(n.ManagerStatus.Reachability)
 			labels[swarmLabelNodeManagerAddr] = model.LabelValue(n.ManagerStatus.Addr)
 		}

discovery/moby/services.go

@@ -116,7 +116,7 @@ func (d *Discovery) refreshServices(ctx context.Context) ([]*targetgroup.Group,
 					labels[model.LabelName(k)] = model.LabelValue(v)
 				}
 
-				addr := net.JoinHostPort(ip.String(), fmt.Sprintf("%d", d.port))
+				addr := net.JoinHostPort(ip.String(), strconv.Itoa(d.port))
 				labels[model.AddressLabel] = model.LabelValue(addr)
 
 				tg.Targets = append(tg.Targets, labels)

discovery/moby/tasks.go

@@ -150,7 +150,7 @@ func (d *Discovery) refreshTasks(ctx context.Context) ([]*targetgroup.Group, err
 						labels[model.LabelName(k)] = model.LabelValue(v)
 					}
 
-					addr := net.JoinHostPort(ip.String(), fmt.Sprintf("%d", d.port))
+					addr := net.JoinHostPort(ip.String(), strconv.Itoa(d.port))
 					labels[model.AddressLabel] = model.LabelValue(addr)
 
 					tg.Targets = append(tg.Targets, labels)

discovery/openstack/hypervisor.go

@@ -17,6 +17,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"strconv"
 
 	"github.com/go-kit/log"
 	"github.com/gophercloud/gophercloud"
@@ -72,7 +73,7 @@ func (h *HypervisorDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group
 	}
 
 	tg := &targetgroup.Group{
-		Source: fmt.Sprintf("OS_" + h.region),
+		Source: "OS_" + h.region,
 	}
 	// OpenStack API reference
 	// https://developer.openstack.org/api-ref/compute/#list-hypervisors-details
@@ -84,7 +85,7 @@ func (h *HypervisorDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group
 		}
 		for _, hypervisor := range hypervisorList {
 			labels := model.LabelSet{}
-			addr := net.JoinHostPort(hypervisor.HostIP, fmt.Sprintf("%d", h.port))
+			addr := net.JoinHostPort(hypervisor.HostIP, strconv.Itoa(h.port))
 			labels[model.AddressLabel] = model.LabelValue(addr)
 			labels[openstackLabelHypervisorID] = model.LabelValue(hypervisor.ID)
 			labels[openstackLabelHypervisorHostName] = model.LabelValue(hypervisor.HypervisorHostname)

discovery/openstack/instance.go

@@ -17,6 +17,7 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"strconv"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -120,7 +121,7 @@ func (i *InstanceDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group,
 	}
 	pager := servers.List(client, opts)
 	tg := &targetgroup.Group{
-		Source: fmt.Sprintf("OS_" + i.region),
+		Source: "OS_" + i.region,
 	}
 	err = pager.EachPage(func(page pagination.Page) (bool, error) {
 		if ctx.Err() != nil {
@@ -194,7 +195,7 @@ func (i *InstanceDiscovery) refresh(ctx context.Context) ([]*targetgroup.Group,
 					if val, ok := floatingIPList[floatingIPKey{id: s.ID, fixed: addr}]; ok {
 						lbls[openstackLabelPublicIP] = model.LabelValue(val)
 					}
-					addr = net.JoinHostPort(addr, fmt.Sprintf("%d", i.port))
+					addr = net.JoinHostPort(addr, strconv.Itoa(i.port))
 					lbls[model.AddressLabel] = model.LabelValue(addr)
 
 					tg.Targets = append(tg.Targets, lbls)

discovery/ovhcloud/dedicated_server.go

@@ -144,12 +144,12 @@ func (d *dedicatedServerDiscovery) refresh(context.Context) ([]*targetgroup.Grou
 			model.InstanceLabel:                             model.LabelValue(server.Name),
 			dedicatedServerLabelPrefix + "state":            model.LabelValue(server.State),
 			dedicatedServerLabelPrefix + "commercial_range": model.LabelValue(server.CommercialRange),
-			dedicatedServerLabelPrefix + "link_speed":       model.LabelValue(fmt.Sprintf("%d", server.LinkSpeed)),
+			dedicatedServerLabelPrefix + "link_speed":       model.LabelValue(strconv.Itoa(server.LinkSpeed)),
 			dedicatedServerLabelPrefix + "rack":             model.LabelValue(server.Rack),
 			dedicatedServerLabelPrefix + "no_intervention":  model.LabelValue(strconv.FormatBool(server.NoIntervention)),
 			dedicatedServerLabelPrefix + "os":               model.LabelValue(server.Os),
 			dedicatedServerLabelPrefix + "support_level":    model.LabelValue(server.SupportLevel),
-			dedicatedServerLabelPrefix + "server_id":        model.LabelValue(fmt.Sprintf("%d", server.ServerID)),
+			dedicatedServerLabelPrefix + "server_id":        model.LabelValue(strconv.FormatInt(server.ServerID, 10)),
 			dedicatedServerLabelPrefix + "reverse":          model.LabelValue(server.Reverse),
 			dedicatedServerLabelPrefix + "datacenter":       model.LabelValue(server.Datacenter),
 			dedicatedServerLabelPrefix + "name":             model.LabelValue(server.Name),

discovery/ovhcloud/vps.go

@@ -19,6 +19,7 @@ import (
 	"net/netip"
 	"net/url"
 	"path"
+	"strconv"
 
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
@@ -161,21 +162,21 @@ func (d *vpsDiscovery) refresh(context.Context) ([]*targetgroup.Group, error) {
 			model.InstanceLabel:                      model.LabelValue(server.Name),
 			vpsLabelPrefix + "offer":                 model.LabelValue(server.Model.Offer),
 			vpsLabelPrefix + "datacenter":            model.LabelValue(fmt.Sprintf("%+v", server.Model.Datacenter)),
-			vpsLabelPrefix + "model_vcore":           model.LabelValue(fmt.Sprintf("%d", server.Model.Vcore)),
+			vpsLabelPrefix + "model_vcore":           model.LabelValue(strconv.Itoa(server.Model.Vcore)),
-			vpsLabelPrefix + "maximum_additional_ip": model.LabelValue(fmt.Sprintf("%d", server.Model.MaximumAdditionalIP)),
+			vpsLabelPrefix + "maximum_additional_ip": model.LabelValue(strconv.Itoa(server.Model.MaximumAdditionalIP)),
 			vpsLabelPrefix + "version":               model.LabelValue(server.Model.Version),
 			vpsLabelPrefix + "model_name":            model.LabelValue(server.Model.Name),
-			vpsLabelPrefix + "disk":                  model.LabelValue(fmt.Sprintf("%d", server.Model.Disk)),
+			vpsLabelPrefix + "disk":                  model.LabelValue(strconv.Itoa(server.Model.Disk)),
-			vpsLabelPrefix + "memory":                model.LabelValue(fmt.Sprintf("%d", server.Model.Memory)),
+			vpsLabelPrefix + "memory":                model.LabelValue(strconv.Itoa(server.Model.Memory)),
 			vpsLabelPrefix + "zone":                  model.LabelValue(server.Zone),
 			vpsLabelPrefix + "display_name":          model.LabelValue(server.DisplayName),
 			vpsLabelPrefix + "cluster":               model.LabelValue(server.Cluster),
 			vpsLabelPrefix + "state":                 model.LabelValue(server.State),
 			vpsLabelPrefix + "name":                  model.LabelValue(server.Name),
 			vpsLabelPrefix + "netboot_mode":          model.LabelValue(server.NetbootMode),
-			vpsLabelPrefix + "memory_limit":          model.LabelValue(fmt.Sprintf("%d", server.MemoryLimit)),
+			vpsLabelPrefix + "memory_limit":          model.LabelValue(strconv.Itoa(server.MemoryLimit)),
 			vpsLabelPrefix + "offer_type":            model.LabelValue(server.OfferType),
-			vpsLabelPrefix + "vcore":                 model.LabelValue(fmt.Sprintf("%d", server.Vcore)),
+			vpsLabelPrefix + "vcore":                 model.LabelValue(strconv.Itoa(server.Vcore)),
 			vpsLabelPrefix + "ipv4":                  model.LabelValue(ipv4),
 			vpsLabelPrefix + "ipv6":                  model.LabelValue(ipv6),
 		}

discovery/puppetdb/puppetdb.go

@@ -237,7 +237,7 @@ func (d *Discovery) refresh(ctx context.Context) ([]*targetgroup.Group, error) {
 			pdbLabelResource:    model.LabelValue(resource.Resource),
 			pdbLabelType:        model.LabelValue(resource.Type),
 			pdbLabelTitle:       model.LabelValue(resource.Title),
-			pdbLabelExported:    model.LabelValue(fmt.Sprintf("%t", resource.Exported)),
+			pdbLabelExported:    model.LabelValue(strconv.FormatBool(resource.Exported)),
 			pdbLabelFile:        model.LabelValue(resource.File),
 			pdbLabelEnvironment: model.LabelValue(resource.Environment),
 		}

discovery/uyuni/uyuni.go

@@ -20,6 +20,7 @@ import (
 	"net/http"
 	"net/url"
 	"path"
+	"strconv"
 	"strings"
 	"time"
 
@@ -269,7 +270,7 @@ func (d *Discovery) getEndpointLabels(
 		model.AddressLabel:       model.LabelValue(addr),
 		uyuniLabelMinionHostname: model.LabelValue(networkInfo.Hostname),
 		uyuniLabelPrimaryFQDN:    model.LabelValue(networkInfo.PrimaryFQDN),
-		uyuniLablelSystemID:      model.LabelValue(fmt.Sprintf("%d", endpoint.SystemID)),
+		uyuniLablelSystemID:      model.LabelValue(strconv.Itoa(endpoint.SystemID)),
 		uyuniLablelGroups:        model.LabelValue(strings.Join(managedGroupNames, d.separator)),
 		uyuniLablelEndpointName:  model.LabelValue(endpoint.EndpointName),
 		uyuniLablelExporter:      model.LabelValue(endpoint.ExporterName),

discovery/zookeeper/zookeeper.go

@@ -280,17 +280,17 @@ func parseServersetMember(data []byte, path string) (model.LabelSet, error) {
 	labels := model.LabelSet{}
 	labels[serversetPathLabel] = model.LabelValue(path)
 	labels[model.AddressLabel] = model.LabelValue(
-		net.JoinHostPort(member.ServiceEndpoint.Host, fmt.Sprintf("%d", member.ServiceEndpoint.Port)))
+		net.JoinHostPort(member.ServiceEndpoint.Host, strconv.Itoa(member.ServiceEndpoint.Port)))
 
 	labels[serversetEndpointLabelPrefix+"_host"] = model.LabelValue(member.ServiceEndpoint.Host)
-	labels[serversetEndpointLabelPrefix+"_port"] = model.LabelValue(fmt.Sprintf("%d", member.ServiceEndpoint.Port))
+	labels[serversetEndpointLabelPrefix+"_port"] = model.LabelValue(strconv.Itoa(member.ServiceEndpoint.Port))
 
 	for name, endpoint := range member.AdditionalEndpoints {
 		cleanName := model.LabelName(strutil.SanitizeLabelName(name))
 		labels[serversetEndpointLabelPrefix+"_host_"+cleanName] = model.LabelValue(
 			endpoint.Host)
 		labels[serversetEndpointLabelPrefix+"_port_"+cleanName] = model.LabelValue(
-			fmt.Sprintf("%d", endpoint.Port))
+			strconv.Itoa(endpoint.Port))
 	}
 
 	labels[serversetStatusLabel] = model.LabelValue(member.Status)
@@ -321,10 +321,10 @@ func parseNerveMember(data []byte, path string) (model.LabelSet, error) {
 	labels := model.LabelSet{}
 	labels[nervePathLabel] = model.LabelValue(path)
 	labels[model.AddressLabel] = model.LabelValue(
-		net.JoinHostPort(member.Host, fmt.Sprintf("%d", member.Port)))
+		net.JoinHostPort(member.Host, strconv.Itoa(member.Port)))
 
 	labels[nerveEndpointLabelPrefix+"_host"] = model.LabelValue(member.Host)
-	labels[nerveEndpointLabelPrefix+"_port"] = model.LabelValue(fmt.Sprintf("%d", member.Port))
+	labels[nerveEndpointLabelPrefix+"_port"] = model.LabelValue(strconv.Itoa(member.Port))
 	labels[nerveEndpointLabelPrefix+"_name"] = model.LabelValue(member.Name)
 
 	return labels, nil

docs/command-line/prometheus.md

@@ -48,7 +48,7 @@ The Prometheus monitoring server
 | <code class="text-nowrap">--rules.alert.for-outage-tolerance</code> | Max time to tolerate prometheus outage for restoring "for" state of alert. Use with server mode only. | `1h` |
 | <code class="text-nowrap">--rules.alert.for-grace-period</code> | Minimum duration between alert and restored "for" state. This is maintained only for alerts with configured "for" time greater than grace period. Use with server mode only. | `10m` |
 | <code class="text-nowrap">--rules.alert.resend-delay</code> | Minimum amount of time to wait before resending an alert to Alertmanager. Use with server mode only. | `1m` |
-| <code class="text-nowrap">--rules.max-concurrent-evals</code> | Global concurrency limit for independent rules that can run concurrently. Use with server mode only. | `4` |
+| <code class="text-nowrap">--rules.max-concurrent-evals</code> | Global concurrency limit for independent rules that can run concurrently. When set, "query.max-concurrency" may need to be adjusted accordingly. Use with server mode only. | `4` |
 | <code class="text-nowrap">--alertmanager.notification-queue-capacity</code> | The capacity of the queue for pending Alertmanager notifications. Use with server mode only. | `10000` |
 | <code class="text-nowrap">--query.lookback-delta</code> | The maximum lookback duration for retrieving metrics during expression evaluations and federation. Use with server mode only. | `5m` |
 | <code class="text-nowrap">--query.timeout</code> | Maximum time a query may take before being aborted. Use with server mode only. | `2m` |

docs/command-line/promtool.md

@@ -566,6 +566,7 @@ Dump samples from a TSDB.
 
 | Flag | Description | Default |
 | --- | --- | --- |
+| <code class="text-nowrap">--sandbox-dir-root</code> | Root directory where a sandbox directory would be created in case WAL replay generates chunks. The sandbox directory is cleaned up at the end. | `data/` |
 | <code class="text-nowrap">--min-time</code> | Minimum timestamp to dump. | `-9223372036854775808` |
 | <code class="text-nowrap">--max-time</code> | Maximum timestamp to dump. | `9223372036854775807` |
 | <code class="text-nowrap">--match</code> | Series selector. Can be specified multiple times. | `{__name__=~'(?s:.*)'}` |
@@ -584,7 +585,7 @@ Dump samples from a TSDB.
 
 ##### `promtool tsdb dump-openmetrics`
 
-[Experimental] Dump samples from a TSDB into OpenMetrics format. Native histograms are not dumped.
+[Experimental] Dump samples from a TSDB into OpenMetrics text format, excluding native histograms and staleness markers, which are not representable in OpenMetrics.
 
 
 
@@ -592,6 +593,7 @@ Dump samples from a TSDB.
 
 | Flag | Description | Default |
 | --- | --- | --- |
+| <code class="text-nowrap">--sandbox-dir-root</code> | Root directory where a sandbox directory would be created in case WAL replay generates chunks. The sandbox directory is cleaned up at the end. | `data/` |
 | <code class="text-nowrap">--min-time</code> | Minimum timestamp to dump. | `-9223372036854775808` |
 | <code class="text-nowrap">--max-time</code> | Maximum timestamp to dump. | `9223372036854775807` |
 | <code class="text-nowrap">--match</code> | Series selector. Can be specified multiple times. | `{__name__=~'(?s:.*)'}` |

docs/configuration/configuration.md

@@ -1467,6 +1467,7 @@ For OVHcloud's [public cloud instances](https://www.ovhcloud.com/en/public-cloud
 * `__meta_ovhcloud_dedicated_server_ipv6`: the IPv6 of the server
 * `__meta_ovhcloud_dedicated_server_link_speed`: the link speed of the server
 * `__meta_ovhcloud_dedicated_server_name`: the name of the server
+* `__meta_ovhcloud_dedicated_server_no_intervention`: whether datacenter intervention is disabled for the server
 * `__meta_ovhcloud_dedicated_server_os`: the operating system of the server
 * `__meta_ovhcloud_dedicated_server_rack`: the rack of the server
 * `__meta_ovhcloud_dedicated_server_reverse`: the reverse DNS name of the server
@@ -3673,7 +3674,8 @@ queue_config:
   [ min_shards: <int> | default = 1 ]
   # Maximum number of samples per send.
   [ max_samples_per_send: <int> | default = 2000]
-  # Maximum time a sample will wait in buffer.
+  # Maximum time a sample will wait for a send. The sample might wait less
+  # if the buffer is full. Further time might pass due to potential retries.
   [ batch_send_deadline: <duration> | default = 5s ]
   # Initial retry delay. Gets doubled for every retry.
   [ min_backoff: <duration> | default = 30ms ]

docs/storage.md

@@ -197,6 +197,9 @@ or time-series database to Prometheus. To do so, the user must first convert the
 source data into [OpenMetrics](https://openmetrics.io/) format, which is the
 input format for the backfilling as described below.
 
+Note that native histograms and staleness markers are not supported by this
+procedure, as they cannot be represented in the OpenMetrics format.
+
 ### Usage
 
 Backfilling can be used via the Promtool command line. Promtool will write the blocks

documentation/examples/custom-sd/adapter-usage/main.go

@@ -127,9 +127,9 @@ func (d *discovery) parseServiceNodes(resp *http.Response, name string) (*target
 		// since the service may be registered remotely through a different node.
 		var addr string
 		if node.ServiceAddress != "" {
-			addr = net.JoinHostPort(node.ServiceAddress, fmt.Sprintf("%d", node.ServicePort))
+			addr = net.JoinHostPort(node.ServiceAddress, strconv.Itoa(node.ServicePort))
 		} else {
-			addr = net.JoinHostPort(node.Address, fmt.Sprintf("%d", node.ServicePort))
+			addr = net.JoinHostPort(node.Address, strconv.Itoa(node.ServicePort))
 		}
 
 		target := model.LabelSet{model.AddressLabel: model.LabelValue(addr)}

documentation/prometheus-mixin/config.libsonnet

@@ -44,5 +44,10 @@
       // The default refresh time for all dashboards, default to 60s
       refresh: '60s',
     },
+
+    // Opt-out of multi-cluster dashboards by overriding this.
+    showMultiCluster: true,
+    // The cluster label to infer the cluster name from.
+    clusterLabel: 'cluster',
   },
 }

documentation/prometheus-mixin/dashboards.libsonnet

@@ -10,21 +10,32 @@ local template = grafana.template;
 {
   grafanaDashboards+:: {
     'prometheus.json':
-      g.dashboard(
+      local showMultiCluster = $._config.showMultiCluster;
+      local dashboard = g.dashboard(
         '%(prefix)sOverview' % $._config.grafanaPrometheus
-      )
+      );
-      .addMultiTemplate('cluster', 'prometheus_build_info{%(prometheusSelector)s}' % $._config, 'cluster')
+      local templatedDashboard = if showMultiCluster then
-      .addMultiTemplate('job', 'prometheus_build_info{cluster=~"$cluster"}', 'job')
+        dashboard
-      .addMultiTemplate('instance', 'prometheus_build_info{cluster=~"$cluster", job=~"$job"}', 'instance')
+        .addMultiTemplate('cluster', 'prometheus_build_info{%(prometheusSelector)s}' % $._config, $._config.clusterLabel)
+        .addMultiTemplate('job', 'prometheus_build_info{cluster=~"$cluster"}', 'job')
+        .addMultiTemplate('instance', 'prometheus_build_info{cluster=~"$cluster", job=~"$job"}', 'instance')
+      else
+        dashboard
+        .addMultiTemplate('job', 'prometheus_build_info{%(prometheusSelector)s}' % $._config, 'job')
+        .addMultiTemplate('instance', 'prometheus_build_info{job=~"$job"}', 'instance');
+      templatedDashboard
       .addRow(
         g.row('Prometheus Stats')
         .addPanel(
           g.panel('Prometheus Stats') +
-          g.tablePanel([
+          g.tablePanel(if showMultiCluster then [
             'count by (cluster, job, instance, version) (prometheus_build_info{cluster=~"$cluster", job=~"$job", instance=~"$instance"})',
             'max by (cluster, job, instance) (time() - process_start_time_seconds{cluster=~"$cluster", job=~"$job", instance=~"$instance"})',
+          ] else [
+            'count by (job, instance, version) (prometheus_build_info{job=~"$job", instance=~"$instance"})',
+            'max by (job, instance) (time() - process_start_time_seconds{job=~"$job", instance=~"$instance"})',
           ], {
-            cluster: { alias: 'Cluster' },
+            cluster: { alias: if showMultiCluster then 'Cluster' else '' },
             job: { alias: 'Job' },
             instance: { alias: 'Instance' },
             version: { alias: 'Version' },
@@ -37,12 +48,18 @@ local template = grafana.template;
         g.row('Discovery')
         .addPanel(
           g.panel('Target Sync') +
-          g.queryPanel('sum(rate(prometheus_target_sync_length_seconds_sum{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[5m])) by (cluster, job, scrape_job, instance) * 1e3', '{{cluster}}:{{job}}:{{instance}}:{{scrape_job}}') +
+          g.queryPanel(if showMultiCluster then 'sum(rate(prometheus_target_sync_length_seconds_sum{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[5m])) by (cluster, job, scrape_job, instance) * 1e3'
+                       else 'sum(rate(prometheus_target_sync_length_seconds_sum{job=~"$job",instance=~"$instance"}[5m])) by (scrape_job) * 1e3',
+                       if showMultiCluster then '{{cluster}}:{{job}}:{{instance}}:{{scrape_job}}'
+                       else '{{scrape_job}}') +
           { yaxes: g.yaxes('ms') }
         )
         .addPanel(
           g.panel('Targets') +
-          g.queryPanel('sum by (cluster, job, instance) (prometheus_sd_discovered_targets{cluster=~"$cluster", job=~"$job",instance=~"$instance"})', '{{cluster}}:{{job}}:{{instance}}') +
+          g.queryPanel(if showMultiCluster then 'sum by (cluster, job, instance) (prometheus_sd_discovered_targets{cluster=~"$cluster", job=~"$job",instance=~"$instance"})'
+                       else 'sum(prometheus_sd_discovered_targets{job=~"$job",instance=~"$instance"})',
+                       if showMultiCluster then '{{cluster}}:{{job}}:{{instance}}'
+                       else 'Targets') +
           g.stack
         )
       )
@@ -50,29 +67,47 @@ local template = grafana.template;
         g.row('Retrieval')
         .addPanel(
           g.panel('Average Scrape Interval Duration') +
-          g.queryPanel('rate(prometheus_target_interval_length_seconds_sum{cluster=~"$cluster", job=~"$job",instance=~"$instance"}[5m]) / rate(prometheus_target_interval_length_seconds_count{cluster=~"$cluster", job=~"$job",instance=~"$instance"}[5m]) * 1e3', '{{cluster}}:{{job}}:{{instance}} {{interval}} configured') +
+          g.queryPanel(if showMultiCluster then 'rate(prometheus_target_interval_length_seconds_sum{cluster=~"$cluster", job=~"$job",instance=~"$instance"}[5m]) / rate(prometheus_target_interval_length_seconds_count{cluster=~"$cluster", job=~"$job",instance=~"$instance"}[5m]) * 1e3'
+                       else 'rate(prometheus_target_interval_length_seconds_sum{job=~"$job",instance=~"$instance"}[5m]) / rate(prometheus_target_interval_length_seconds_count{job=~"$job",instance=~"$instance"}[5m]) * 1e3',
+                       if showMultiCluster then '{{cluster}}:{{job}}:{{instance}} {{interval}} configured'
+                       else '{{interval}} configured') +
           { yaxes: g.yaxes('ms') }
         )
         .addPanel(
           g.panel('Scrape failures') +
-          g.queryPanel([
+          g.queryPanel(if showMultiCluster then [
             'sum by (cluster, job, instance) (rate(prometheus_target_scrapes_exceeded_body_size_limit_total{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[1m]))',
             'sum by (cluster, job, instance) (rate(prometheus_target_scrapes_exceeded_sample_limit_total{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[1m]))',
             'sum by (cluster, job, instance) (rate(prometheus_target_scrapes_sample_duplicate_timestamp_total{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[1m]))',
             'sum by (cluster, job, instance) (rate(prometheus_target_scrapes_sample_out_of_bounds_total{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[1m]))',
             'sum by (cluster, job, instance) (rate(prometheus_target_scrapes_sample_out_of_order_total{cluster=~"$cluster",job=~"$job",instance=~"$instance"}[1m]))',
-          ], [
+          ] else [
+            'sum by (job) (rate(prometheus_target_scrapes_exceeded_body_size_limit_total[1m]))',
+            'sum by (job) (rate(prometheus_target_scrapes_exceeded_sample_limit_total[1m]))',
+            'sum by (job) (rate(prometheus_target_scrapes_sample_duplicate_timestamp_total[1m]))',
+            'sum by (job) (rate(prometheus_target_scrapes_sample_out_of_bounds_total[1m]))',
+            'sum by (job) (rate(prometheus_target_scrapes_sample_out_of_order_total[1m]))',
+          ], if showMultiCluster then [
             'exceeded body size limit: {{cluster}} {{job}} {{instance}}',
             'exceeded sample limit: {{cluster}} {{job}} {{instance}}',
             'duplicate timestamp: {{cluster}} {{job}} {{instance}}',
             'out of bounds: {{cluster}} {{job}} {{instance}}',
             'out of order: {{cluster}} {{job}} {{instance}}',
+          ] else [
+            'exceeded body size limit: {{job}}',
+            'exceeded sample limit: {{job}}',
+            'duplicate timestamp: {{job}}',
+            'out of bounds: {{job}}',
+            'out of order: {{job}}',
           ]) +
           g.stack
         )
         .addPanel(
           g.panel('Appended Samples') +
-          g.queryPanel('rate(prometheus_tsdb_head_samples_appended_total{cluster=~"$cluster", job=~"$job",instance=~"$instance"}[5m])', '{{cluster}} {{job}} {{instance}}') +
+          g.queryPanel(if showMultiCluster then 'rate(prometheus_tsdb_head_samples_appended_total{cluster=~"$cluster", job=~"$job",instance=~"$instance"}[5m])'
+                       else 'rate(prometheus_tsdb_head_samples_appended_total{job=~"$job",instance=~"$instance"}[5m])',
+                       if showMultiCluster then '{{cluster}} {{job}} {{instance}}'
+                       else '{{job}} {{instance}}') +
           g.stack
         )
       )
@@ -80,12 +115,18 @@ local template = grafana.template;
         g.row('Storage')
         .addPanel(
           g.panel('Head Series') +
-          g.queryPanel('prometheus_tsdb_head_series{cluster=~"$cluster",job=~"$job",instance=~"$instance"}', '{{cluster}} {{job}} {{instance}} head series') +
+          g.queryPanel(if showMultiCluster then 'prometheus_tsdb_head_series{cluster=~"$cluster",job=~"$job",instance=~"$instance"}'
+                       else 'prometheus_tsdb_head_series{job=~"$job",instance=~"$instance"}',
+                       if showMultiCluster then '{{cluster}} {{job}} {{instance}} head series'
+                       else '{{job}} {{instance}} head series') +
           g.stack
         )
         .addPanel(
           g.panel('Head Chunks') +
-          g.queryPanel('prometheus_tsdb_head_chunks{cluster=~"$cluster",job=~"$job",instance=~"$instance"}', '{{cluster}} {{job}} {{instance}} head chunks') +
+          g.queryPanel(if showMultiCluster then 'prometheus_tsdb_head_chunks{cluster=~"$cluster",job=~"$job",instance=~"$instance"}'
+                       else 'prometheus_tsdb_head_chunks{job=~"$job",instance=~"$instance"}',
+                       if showMultiCluster then '{{cluster}} {{job}} {{instance}} head chunks'
+                       else '{{job}} {{instance}} head chunks') +
           g.stack
         )
       )
@@ -93,12 +134,18 @@ local template = grafana.template;
         g.row('Query')
         .addPanel(
           g.panel('Query Rate') +
-          g.queryPanel('rate(prometheus_engine_query_duration_seconds_count{cluster=~"$cluster",job=~"$job",instance=~"$instance",slice="inner_eval"}[5m])', '{{cluster}} {{job}} {{instance}}') +
+          g.queryPanel(if showMultiCluster then 'rate(prometheus_engine_query_duration_seconds_count{cluster=~"$cluster",job=~"$job",instance=~"$instance",slice="inner_eval"}[5m])'
+                       else 'rate(prometheus_engine_query_duration_seconds_count{job=~"$job",instance=~"$instance",slice="inner_eval"}[5m])',
+                       if showMultiCluster then '{{cluster}} {{job}} {{instance}}'
+                       else '{{job}} {{instance}}') +
           g.stack,
         )
         .addPanel(
           g.panel('Stage Duration') +
-          g.queryPanel('max by (slice) (prometheus_engine_query_duration_seconds{quantile="0.9",cluster=~"$cluster", job=~"$job",instance=~"$instance"}) * 1e3', '{{slice}}') +
+          g.queryPanel(if showMultiCluster then 'max by (slice) (prometheus_engine_query_duration_seconds{quantile="0.9",cluster=~"$cluster", job=~"$job",instance=~"$instance"}) * 1e3'
+                       else 'max by (slice) (prometheus_engine_query_duration_seconds{quantile="0.9",job=~"$job",instance=~"$instance"}) * 1e3',
+                       if showMultiCluster then '{{slice}}'
+                       else '{{slice}}') +
           { yaxes: g.yaxes('ms') } +
           g.stack,
         )

go.mod

@@ -60,7 +60,6 @@ require (
 	github.com/shurcooL/httpfs v0.0.0-20230704072500-f1e31cf0ba5c
 	github.com/stretchr/testify v1.9.0
 	github.com/vultr/govultr/v2 v2.17.2
-	go.opentelemetry.io/collector/featuregate v1.5.0
 	go.opentelemetry.io/collector/pdata v1.5.0
 	go.opentelemetry.io/collector/semconv v0.98.0
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.50.0
@@ -151,7 +150,6 @@ require (
 	github.com/hashicorp/go-multierror v1.1.1 // indirect
 	github.com/hashicorp/go-retryablehttp v0.7.4 // indirect
 	github.com/hashicorp/go-rootcerts v1.0.2 // indirect
-	github.com/hashicorp/go-version v1.6.0 // indirect
 	github.com/hashicorp/golang-lru v0.6.0 // indirect
 	github.com/hashicorp/serf v0.10.1 // indirect
 	github.com/imdario/mergo v0.3.16 // indirect

go.sum

@@ -722,8 +722,6 @@ go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.22.4/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
 go.opencensus.io v0.24.0/go.mod h1:vNK8G9p7aAivkbmorf4v+7Hgx+Zs0yY+0fOtgBfjQKo=
-go.opentelemetry.io/collector/featuregate v1.5.0 h1:uK8qnYQKz1TMkK+FDTFsywg/EybW/gbnOUaPNUkRznM=
-go.opentelemetry.io/collector/featuregate v1.5.0/go.mod h1:w7nUODKxEi3FLf1HslCiE6YWtMtOOrMnSwsDam8Mg9w=
 go.opentelemetry.io/collector/pdata v1.5.0 h1:1fKTmUpr0xCOhP/B0VEvtz7bYPQ45luQ8XFyA07j8LE=
 go.opentelemetry.io/collector/pdata v1.5.0/go.mod h1:TYj8aKRWZyT/KuKQXKyqSEvK/GV+slFaDMEI+Ke64Yw=
 go.opentelemetry.io/collector/semconv v0.98.0 h1:zO4L4TmlxXoYu8UgPeYElGY19BW7wPjM+quL5CzoOoY=

model/histogram/float_histogram_test.go

@@ -14,9 +14,9 @@
 package histogram
 
 import (
-	"fmt"
 	"math"
 	"math/rand"
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -2134,7 +2134,7 @@ func TestAllFloatBucketIterator(t *testing.T) {
 	}
 
 	for i, c := range cases {
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			var expBuckets, actBuckets []Bucket[float64]
 
 			if c.includeNeg {
@@ -2360,7 +2360,7 @@ func TestAllReverseFloatBucketIterator(t *testing.T) {
 	}
 
 	for i, c := range cases {
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			var expBuckets, actBuckets []Bucket[float64]
 
 			if c.includePos {

model/histogram/histogram_test.go

@@ -14,8 +14,8 @@
 package histogram
 
 import (
-	"fmt"
 	"math"
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -72,7 +72,7 @@ func TestHistogramString(t *testing.T) {
 	}
 
 	for i, c := range cases {
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			actualString := c.histogram.String()
 			require.Equal(t, c.expectedString, actualString)
 		})
@@ -211,7 +211,7 @@ func TestCumulativeBucketIterator(t *testing.T) {
 	}
 
 	for i, c := range cases {
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			it := c.histogram.CumulativeBucketIterator()
 			actualBuckets := make([]Bucket[uint64], 0, len(c.expectedBuckets))
 			for it.Next() {
@@ -371,7 +371,7 @@ func TestRegularBucketIterator(t *testing.T) {
 	}
 
 	for i, c := range cases {
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			it := c.histogram.PositiveBucketIterator()
 			actualPositiveBuckets := make([]Bucket[uint64], 0, len(c.expectedPositiveBuckets))
 			for it.Next() {

model/labels/labels_test.go

@@ -17,6 +17,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -732,7 +733,7 @@ func TestScratchBuilder(t *testing.T) {
 			want: FromStrings("ddd", "444"),
 		},
 	} {
-		t.Run(fmt.Sprint(i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			b := NewScratchBuilder(len(tcase.add))
 			for _, lbl := range tcase.add {
 				b.Add(lbl.Name, lbl.Value)

model/labels/matcher.go

@@ -14,7 +14,8 @@
 package labels
 
 import (
-	"fmt"
+	"bytes"
+	"strconv"
 )
 
 // MatchType is an enum for label matching types.
@@ -78,7 +79,29 @@ func MustNewMatcher(mt MatchType, name, val string) *Matcher {
 }
 
 func (m *Matcher) String() string {
-	return fmt.Sprintf("%s%s%q", m.Name, m.Type, m.Value)
+	// Start a buffer with a pre-allocated size on stack to cover most needs.
+	var bytea [1024]byte
+	b := bytes.NewBuffer(bytea[:0])
+
+	if m.shouldQuoteName() {
+		b.Write(strconv.AppendQuote(b.AvailableBuffer(), m.Name))
+	} else {
+		b.WriteString(m.Name)
+	}
+	b.WriteString(m.Type.String())
+	b.Write(strconv.AppendQuote(b.AvailableBuffer(), m.Value))
+
+	return b.String()
+}
+
+func (m *Matcher) shouldQuoteName() bool {
+	for i, c := range m.Name {
+		if c == '_' || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (i > 0 && c >= '0' && c <= '9') {
+			continue
+		}
+		return true
+	}
+	return false
 }
 
 // Matches returns whether the matcher matches the given string value.

model/labels/matcher_test.go

@@ -15,6 +15,7 @@ package labels
 
 import (
 	"fmt"
+	"math/rand"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -225,3 +226,128 @@ func BenchmarkNewMatcher(b *testing.B) {
 		}
 	})
 }
+
+func BenchmarkMatcher_String(b *testing.B) {
+	type benchCase struct {
+		name     string
+		matchers []*Matcher
+	}
+	cases := []benchCase{
+		{
+			name: "short name equal",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchEqual, "foo", "bar"),
+				MustNewMatcher(MatchEqual, "bar", "baz"),
+				MustNewMatcher(MatchEqual, "abc", "def"),
+				MustNewMatcher(MatchEqual, "ghi", "klm"),
+				MustNewMatcher(MatchEqual, "nop", "qrs"),
+			},
+		},
+		{
+			name: "short quoted name not equal",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchEqual, "f.o", "bar"),
+				MustNewMatcher(MatchEqual, "b.r", "baz"),
+				MustNewMatcher(MatchEqual, "a.c", "def"),
+				MustNewMatcher(MatchEqual, "g.i", "klm"),
+				MustNewMatcher(MatchEqual, "n.p", "qrs"),
+			},
+		},
+		{
+			name: "short quoted name with quotes not equal",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchEqual, `"foo"`, "bar"),
+				MustNewMatcher(MatchEqual, `"foo"`, "baz"),
+				MustNewMatcher(MatchEqual, `"foo"`, "def"),
+				MustNewMatcher(MatchEqual, `"foo"`, "klm"),
+				MustNewMatcher(MatchEqual, `"foo"`, "qrs"),
+			},
+		},
+		{
+			name: "short name value with quotes equal",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchEqual, "foo", `"bar"`),
+				MustNewMatcher(MatchEqual, "bar", `"baz"`),
+				MustNewMatcher(MatchEqual, "abc", `"def"`),
+				MustNewMatcher(MatchEqual, "ghi", `"klm"`),
+				MustNewMatcher(MatchEqual, "nop", `"qrs"`),
+			},
+		},
+		{
+			name: "short name and long value regexp",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchRegexp, "foo", "five_six_seven_eight_nine_ten_one_two_three_four"),
+				MustNewMatcher(MatchRegexp, "bar", "one_two_three_four_five_six_seven_eight_nine_ten"),
+				MustNewMatcher(MatchRegexp, "abc", "two_three_four_five_six_seven_eight_nine_ten_one"),
+				MustNewMatcher(MatchRegexp, "ghi", "three_four_five_six_seven_eight_nine_ten_one_two"),
+				MustNewMatcher(MatchRegexp, "nop", "four_five_six_seven_eight_nine_ten_one_two_three"),
+			},
+		},
+		{
+			name: "short name and long value with quotes equal",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchEqual, "foo", `five_six_seven_eight_nine_ten_"one"_two_three_four`),
+				MustNewMatcher(MatchEqual, "bar", `one_two_three_four_five_six_"seven"_eight_nine_ten`),
+				MustNewMatcher(MatchEqual, "abc", `two_three_four_five_six_seven_"eight"_nine_ten_one`),
+				MustNewMatcher(MatchEqual, "ghi", `three_four_five_six_seven_eight_"nine"_ten_one_two`),
+				MustNewMatcher(MatchEqual, "nop", `four_five_six_seven_eight_nine_"ten"_one_two_three`),
+			},
+		},
+		{
+			name: "long name regexp",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchRegexp, "one_two_three_four_five_six_seven_eight_nine_ten", "val"),
+				MustNewMatcher(MatchRegexp, "two_three_four_five_six_seven_eight_nine_ten_one", "val"),
+				MustNewMatcher(MatchRegexp, "three_four_five_six_seven_eight_nine_ten_one_two", "val"),
+				MustNewMatcher(MatchRegexp, "four_five_six_seven_eight_nine_ten_one_two_three", "val"),
+				MustNewMatcher(MatchRegexp, "five_six_seven_eight_nine_ten_one_two_three_four", "val"),
+			},
+		},
+		{
+			name: "long quoted name regexp",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchRegexp, "one.two.three.four.five.six.seven.eight.nine.ten", "val"),
+				MustNewMatcher(MatchRegexp, "two.three.four.five.six.seven.eight.nine.ten.one", "val"),
+				MustNewMatcher(MatchRegexp, "three.four.five.six.seven.eight.nine.ten.one.two", "val"),
+				MustNewMatcher(MatchRegexp, "four.five.six.seven.eight.nine.ten.one.two.three", "val"),
+				MustNewMatcher(MatchRegexp, "five.six.seven.eight.nine.ten.one.two.three.four", "val"),
+			},
+		},
+		{
+			name: "long name and long value regexp",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchRegexp, "one_two_three_four_five_six_seven_eight_nine_ten", "five_six_seven_eight_nine_ten_one_two_three_four"),
+				MustNewMatcher(MatchRegexp, "two_three_four_five_six_seven_eight_nine_ten_one", "one_two_three_four_five_six_seven_eight_nine_ten"),
+				MustNewMatcher(MatchRegexp, "three_four_five_six_seven_eight_nine_ten_one_two", "two_three_four_five_six_seven_eight_nine_ten_one"),
+				MustNewMatcher(MatchRegexp, "four_five_six_seven_eight_nine_ten_one_two_three", "three_four_five_six_seven_eight_nine_ten_one_two"),
+				MustNewMatcher(MatchRegexp, "five_six_seven_eight_nine_ten_one_two_three_four", "four_five_six_seven_eight_nine_ten_one_two_three"),
+			},
+		},
+		{
+			name: "long quoted name and long value regexp",
+			matchers: []*Matcher{
+				MustNewMatcher(MatchRegexp, "one.two.three.four.five.six.seven.eight.nine.ten", "five.six.seven.eight.nine.ten.one.two.three.four"),
+				MustNewMatcher(MatchRegexp, "two.three.four.five.six.seven.eight.nine.ten.one", "one.two.three.four.five.six.seven.eight.nine.ten"),
+				MustNewMatcher(MatchRegexp, "three.four.five.six.seven.eight.nine.ten.one.two", "two.three.four.five.six.seven.eight.nine.ten.one"),
+				MustNewMatcher(MatchRegexp, "four.five.six.seven.eight.nine.ten.one.two.three", "three.four.five.six.seven.eight.nine.ten.one.two"),
+				MustNewMatcher(MatchRegexp, "five.six.seven.eight.nine.ten.one.two.three.four", "four.five.six.seven.eight.nine.ten.one.two.three"),
+			},
+		},
+	}
+
+	var mixed []*Matcher
+	for _, bc := range cases {
+		mixed = append(mixed, bc.matchers...)
+	}
+	rand.Shuffle(len(mixed), func(i, j int) { mixed[i], mixed[j] = mixed[j], mixed[i] })
+	cases = append(cases, benchCase{name: "mixed", matchers: mixed})
+
+	for _, bc := range cases {
+		b.Run(bc.name, func(b *testing.B) {
+			for i := 0; i <= b.N; i++ {
+				m := bc.matchers[i%len(bc.matchers)]
+				_ = m.String()
+			}
+		})
+	}
+}

model/labels/regexp.go

@@ -828,7 +828,12 @@ type zeroOrOneCharacterStringMatcher struct {
 }
 
 func (m *zeroOrOneCharacterStringMatcher) Matches(s string) bool {
-	if moreThanOneRune(s) {
+	// If there's more than one rune in the string, then it can't match.
+	if r, size := utf8.DecodeRuneInString(s); r == utf8.RuneError {
+		// Size is 0 for empty strings, 1 for invalid rune.
+		// Empty string matches, invalid rune matches if there isn't anything else.
+		return size == len(s)
+	} else if size < len(s) {
 		return false
 	}
 
@@ -840,27 +845,6 @@ func (m *zeroOrOneCharacterStringMatcher) Matches(s string) bool {
 	return s[0] != '\n'
 }
 
-// moreThanOneRune returns true if there are more than one runes in the string.
-// It doesn't check whether the string is valid UTF-8.
-// The return value should be always equal to utf8.RuneCountInString(s) > 1,
-// but the function is optimized for the common case where the string prefix is ASCII.
-func moreThanOneRune(s string) bool {
-	// If len(s) is exactly one or zero, there can't be more than one rune.
-	// Exit through this path quickly.
-	if len(s) <= 1 {
-		return false
-	}
-
-	// There's one or more bytes:
-	// If first byte is ASCII then there are multiple runes if there are more bytes after that.
-	if s[0] < utf8.RuneSelf {
-		return len(s) > 1
-	}
-
-	// Less common case: first is a multibyte rune.
-	return utf8.RuneCountInString(s) > 1
-}
-
 // trueMatcher is a stringMatcher which matches any string (always returns true).
 type trueMatcher struct{}
 

model/labels/regexp_test.go

@@ -19,6 +19,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unicode/utf8"
 
 	"github.com/grafana/regexp"
 	"github.com/grafana/regexp/syntax"
@@ -36,6 +37,7 @@ var (
 		".*foo",
 		"^.*foo$",
 		"^.+foo$",
+		".?",
 		".*",
 		".+",
 		"foo.+",
@@ -88,6 +90,12 @@ var (
 
 		// Values matching / not matching the test regexps on long alternations.
 		"zQPbMkNO", "zQPbMkNo", "jyyfj00j0061", "jyyfj00j006", "jyyfj00j00612", "NNSPdvMi", "NNSPdvMiXXX", "NNSPdvMixxx", "nnSPdvMi", "nnSPdvMiXXX",
+
+		// Invalid utf8
+		"\xfefoo",
+		"foo\xfe",
+		"\xfd",
+		"\xff\xff",
 	}
 )
 
@@ -926,19 +934,91 @@ func BenchmarkOptimizeEqualStringMatchers(b *testing.B) {
 }
 
 func TestZeroOrOneCharacterStringMatcher(t *testing.T) {
-	matcher := &zeroOrOneCharacterStringMatcher{matchNL: true}
+	t.Run("match newline", func(t *testing.T) {
-	require.True(t, matcher.Matches(""))
+		matcher := &zeroOrOneCharacterStringMatcher{matchNL: true}
-	require.True(t, matcher.Matches("x"))
+		require.True(t, matcher.Matches(""))
-	require.True(t, matcher.Matches("\n"))
+		require.True(t, matcher.Matches("x"))
-	require.False(t, matcher.Matches("xx"))
+		require.True(t, matcher.Matches("\n"))
-	require.False(t, matcher.Matches("\n\n"))
+		require.False(t, matcher.Matches("xx"))
+		require.False(t, matcher.Matches("\n\n"))
+	})
 
-	matcher = &zeroOrOneCharacterStringMatcher{matchNL: false}
+	t.Run("do not match newline", func(t *testing.T) {
-	require.True(t, matcher.Matches(""))
+		matcher := &zeroOrOneCharacterStringMatcher{matchNL: false}
-	require.True(t, matcher.Matches("x"))
+		require.True(t, matcher.Matches(""))
-	require.False(t, matcher.Matches("\n"))
+		require.True(t, matcher.Matches("x"))
-	require.False(t, matcher.Matches("xx"))
+		require.False(t, matcher.Matches("\n"))
-	require.False(t, matcher.Matches("\n\n"))
+		require.False(t, matcher.Matches("xx"))
+		require.False(t, matcher.Matches("\n\n"))
+	})
+
+	t.Run("unicode", func(t *testing.T) {
+		// Just for documentation purposes, emoji1 is 1 rune, emoji2 is 2 runes.
+		// Having this in mind, will make future readers fixing tests easier.
+		emoji1 := "😀"
+		emoji2 := "❤️"
+		require.Equal(t, 1, utf8.RuneCountInString(emoji1))
+		require.Equal(t, 2, utf8.RuneCountInString(emoji2))
+
+		matcher := &zeroOrOneCharacterStringMatcher{matchNL: true}
+		require.True(t, matcher.Matches(emoji1))
+		require.False(t, matcher.Matches(emoji2))
+		require.False(t, matcher.Matches(emoji1+emoji1))
+		require.False(t, matcher.Matches("x"+emoji1))
+		require.False(t, matcher.Matches(emoji1+"x"))
+		require.False(t, matcher.Matches(emoji1+emoji2))
+	})
+
+	t.Run("invalid unicode", func(t *testing.T) {
+		// Just for reference, we also compare to what `^.?$` regular expression matches.
+		re := regexp.MustCompile("^.?$")
+		matcher := &zeroOrOneCharacterStringMatcher{matchNL: true}
+
+		requireMatches := func(s string, expected bool) {
+			t.Helper()
+			require.Equal(t, expected, matcher.Matches(s))
+			require.Equal(t, re.MatchString(s), matcher.Matches(s))
+		}
+
+		requireMatches("\xff", true)
+		requireMatches("x\xff", false)
+		requireMatches("\xffx", false)
+		requireMatches("\xff\xfe", false)
+	})
+}
+
+func BenchmarkZeroOrOneCharacterStringMatcher(b *testing.B) {
+	type benchCase struct {
+		str     string
+		matches bool
+	}
+
+	emoji1 := "😀"
+	emoji2 := "❤️"
+	cases := []benchCase{
+		{"", true},
+		{"x", true},
+		{"\n", true},
+		{"xx", false},
+		{"\n\n", false},
+		{emoji1, true},
+		{emoji2, false},
+		{emoji1 + emoji1, false},
+		{strings.Repeat("x", 100), false},
+		{strings.Repeat(emoji1, 100), false},
+		{strings.Repeat(emoji2, 100), false},
+	}
+
+	matcher := &zeroOrOneCharacterStringMatcher{matchNL: true}
+	b.ResetTimer()
+
+	for n := 0; n < b.N; n++ {
+		c := cases[n%len(cases)]
+		got := matcher.Matches(c.str)
+		if got != c.matches {
+			b.Fatalf("unexpected result for %q: got %t, want %t", c.str, got, c.matches)
+		}
+	}
 }
 
 func TestLiteralPrefixStringMatcher(t *testing.T) {

model/relabel/relabel.go

@@ -17,6 +17,7 @@ import (
 	"crypto/md5"
 	"encoding/binary"
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/grafana/regexp"
@@ -290,7 +291,7 @@ func relabel(cfg *Config, lb *labels.Builder) (keep bool) {
 		hash := md5.Sum([]byte(val))
 		// Use only the last 8 bytes of the hash to give the same result as earlier versions of this code.
 		mod := binary.BigEndian.Uint64(hash[8:]) % cfg.Modulus
-		lb.Set(cfg.TargetLabel, fmt.Sprintf("%d", mod))
+		lb.Set(cfg.TargetLabel, strconv.FormatUint(mod, 10))
 	case LabelMap:
 		lb.Range(func(l labels.Label) {
 			if cfg.Regex.MatchString(l.Name) {

model/relabel/relabel_test.go

@@ -14,7 +14,7 @@
 package relabel
 
 import (
-	"fmt"
+	"strconv"
 	"testing"
 
 	"github.com/prometheus/common/model"
@@ -657,7 +657,7 @@ func TestRelabelValidate(t *testing.T) {
 		},
 	}
 	for i, test := range tests {
-		t.Run(fmt.Sprint(i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			err := test.config.Validate()
 			if test.expected == "" {
 				require.NoError(t, err)

notifier/notifier_test.go

@@ -74,7 +74,7 @@ func TestHandlerNextBatch(t *testing.T) {
 
 	for i := range make([]struct{}, 2*maxBatchSize+1) {
 		h.queue = append(h.queue, &Alert{
-			Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+			Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 		})
 	}
 
@@ -186,10 +186,10 @@ func TestHandlerSendAll(t *testing.T) {
 
 	for i := range make([]struct{}, maxBatchSize) {
 		h.queue = append(h.queue, &Alert{
-			Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+			Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 		})
 		expected = append(expected, &Alert{
-			Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+			Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 		})
 	}
 
@@ -297,23 +297,23 @@ func TestHandlerSendAllRemapPerAm(t *testing.T) {
 	for i := range make([]struct{}, maxBatchSize/2) {
 		h.queue = append(h.queue,
 			&Alert{
-				Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+				Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 			},
 			&Alert{
-				Labels: labels.FromStrings("alertname", "test", "alertnamedrop", fmt.Sprintf("%d", i)),
+				Labels: labels.FromStrings("alertname", "test", "alertnamedrop", strconv.Itoa(i)),
 			},
 		)
 
 		expected1 = append(expected1,
 			&Alert{
-				Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+				Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 			}, &Alert{
-				Labels: labels.FromStrings("alertname", "test", "alertnamedrop", fmt.Sprintf("%d", i)),
+				Labels: labels.FromStrings("alertname", "test", "alertnamedrop", strconv.Itoa(i)),
 			},
 		)
 
 		expected2 = append(expected2, &Alert{
-			Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+			Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 		})
 	}
 
@@ -502,7 +502,7 @@ func TestHandlerQueuing(t *testing.T) {
 	var alerts []*Alert
 	for i := range make([]struct{}, 20*maxBatchSize) {
 		alerts = append(alerts, &Alert{
-			Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+			Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 		})
 	}
 
@@ -762,7 +762,7 @@ func TestHangingNotifier(t *testing.T) {
 			var alerts []*Alert
 			for i := range make([]struct{}, 20*maxBatchSize) {
 				alerts = append(alerts, &Alert{
-					Labels: labels.FromStrings("alertname", fmt.Sprintf("%d", i)),
+					Labels: labels.FromStrings("alertname", strconv.Itoa(i)),
 				})
 			}
 

promql/parser/printer_test.go

@@ -138,6 +138,16 @@ func TestExprString(t *testing.T) {
 		{
 			in: `{__name__="",a="x"}`,
 		},
+		{
+			in: `{"a.b"="c"}`,
+		},
+		{
+			in: `{"0"="1"}`,
+		},
+		{
+			in:  `{"_0"="1"}`,
+			out: `{_0="1"}`,
+		},
 	}
 
 	for _, test := range inputs {

promql/promqltest/testdata/native_histograms.test

@@ -269,3 +269,448 @@ eval instant at 50m histogram_sum(sum(incr_sum_histogram))
 
 eval instant at 50m histogram_sum(sum(last_over_time(incr_sum_histogram[5m])))
     {} 30
+
+# Apply rate function to histogram.
+load 15s
+    histogram_rate {{schema:1 count:12 sum:18.4 z_bucket:2 z_bucket_w:0.001 buckets:[1 2 0 1 1] n_buckets:[1 2 0 1 1]}}+{{schema:1 count:9 sum:18.4 z_bucket:1 z_bucket_w:0.001 buckets:[1 1 0 1 1] n_buckets:[1 1 0 1 1]}}x100
+
+eval instant at 5m rate(histogram_rate[45s])
+    {} {{schema:1 count:0.6 sum:1.2266666666666652 z_bucket:0.06666666666666667 z_bucket_w:0.001 buckets:[0.06666666666666667 0.06666666666666667 0 0.06666666666666667 0.06666666666666667] n_buckets:[0.06666666666666667 0.06666666666666667 0 0.06666666666666667 0.06666666666666667]}}
+
+eval range from 5m to 5m30s step 30s rate(histogram_rate[45s])
+    {} {{schema:1 count:0.6 sum:1.2266666666666652 z_bucket:0.06666666666666667 z_bucket_w:0.001 buckets:[0.06666666666666667 0.06666666666666667 0 0.06666666666666667 0.06666666666666667] n_buckets:[0.06666666666666667 0.06666666666666667 0 0.06666666666666667 0.06666666666666667]}}x1
+
+# Apply count and sum function to histogram.
+load 10m
+    histogram_count_sum_2 {{schema:0 count:24 sum:100 z_bucket:4 z_bucket_w:0.001 buckets:[2 3 0 1 4] n_buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_count(histogram_count_sum_2)
+    {} 24
+
+eval instant at 10m histogram_sum(histogram_count_sum_2)
+    {} 100
+
+# Apply stddev and stdvar function to histogram with {1, 2, 3, 4} (low res).
+load 10m
+   histogram_stddev_stdvar_1 {{schema:2 count:4 sum:10 buckets:[1 0 0 0 1 0 0 1 1]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_1)
+    {} 1.0787993180043811
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_1)
+    {} 1.163807968526718
+
+# Apply stddev and stdvar function to histogram with {1, 1, 1, 1} (high res).
+load 10m
+   histogram_stddev_stdvar_2 {{schema:8 count:10 sum:10 buckets:[1 2 3 4]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_2)
+    {} 0.0048960313898237465
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_2)
+    {} 2.3971123370139447e-05
+
+# Apply stddev and stdvar function to histogram with {-50, -8, 0, 3, 8, 9}.
+load 10m
+   histogram_stddev_stdvar_3 {{schema:3 count:7 sum:62 z_bucket:1 buckets:[0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 ] n_buckets:[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 ]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_3)
+    {} 42.947236400258
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_3)
+    {} 1844.4651144196398
+
+# Apply stddev and stdvar function to histogram with {-100000, -10000, -1000, -888, -888, -100, -50, -9, -8, -3}.
+load 10m
+   histogram_stddev_stdvar_4 {{schema:0 count:10 sum:-112946 z_bucket:0 n_buckets:[0 0 1 1 1 0 1 1 0 0 3 0 0 0 1 0 0 1]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_4)
+    {} 27556.344499842
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_4)
+    {} 759352122.1939945
+
+# Apply stddev and stdvar function to histogram with {-10x10}.
+load 10m
+   histogram_stddev_stdvar_5 {{schema:0 count:10 sum:-100 z_bucket:0 n_buckets:[0 0 0 0 10]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_5)
+    {} 1.3137084989848
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_5)
+    {} 1.725830020304794
+
+# Apply stddev and stdvar function to histogram with {-50, -8, 0, 3, 8, 9, NaN}.
+load 10m
+   histogram_stddev_stdvar_6 {{schema:3 count:7 sum:NaN z_bucket:1 buckets:[0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 ] n_buckets:[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 ]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_6)
+    {} NaN
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_6)
+    {} NaN
+
+# Apply stddev and stdvar function to histogram with {-50, -8, 0, 3, 8, 9, Inf}.
+load 10m
+   histogram_stddev_stdvar_7 {{schema:3 count:7 sum:Inf z_bucket:1 buckets:[0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 ] n_buckets:[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 ]}}x1
+
+eval instant at 10m histogram_stddev(histogram_stddev_stdvar_7)
+    {} NaN
+
+eval instant at 10m histogram_stdvar(histogram_stddev_stdvar_7)
+    {} NaN
+
+# Apply quantile function to histogram with all positive buckets with zero bucket.
+load 10m
+    histogram_quantile_1 {{schema:0 count:12 sum:100 z_bucket:2 z_bucket_w:0.001 buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_quantile(1.001, histogram_quantile_1)
+    {} Inf
+
+eval instant at 10m histogram_quantile(1, histogram_quantile_1)
+    {} 16
+
+eval instant at 10m histogram_quantile(0.99, histogram_quantile_1)
+    {} 15.759999999999998
+
+eval instant at 10m histogram_quantile(0.9, histogram_quantile_1)
+    {} 13.600000000000001
+
+eval instant at 10m histogram_quantile(0.6, histogram_quantile_1)
+    {} 4.799999999999997
+
+eval instant at 10m histogram_quantile(0.5, histogram_quantile_1)
+    {} 1.6666666666666665
+
+eval instant at 10m histogram_quantile(0.1, histogram_quantile_1)
+    {} 0.0006000000000000001
+
+eval instant at 10m histogram_quantile(0, histogram_quantile_1)
+    {} 0
+
+eval instant at 10m histogram_quantile(-1, histogram_quantile_1)
+    {} -Inf
+
+# Apply quantile function to histogram with all negative buckets with zero bucket.
+load 10m
+    histogram_quantile_2 {{schema:0 count:12 sum:100 z_bucket:2 z_bucket_w:0.001 n_buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_quantile(1.001, histogram_quantile_2)
+    {} Inf
+
+eval instant at 10m histogram_quantile(1, histogram_quantile_2)
+    {} 0
+
+eval instant at 10m histogram_quantile(0.99, histogram_quantile_2)
+    {} -6.000000000000048e-05
+
+eval instant at 10m histogram_quantile(0.9, histogram_quantile_2)
+    {} -0.0005999999999999996
+
+eval instant at 10m histogram_quantile(0.5, histogram_quantile_2)
+    {} -1.6666666666666667
+
+eval instant at 10m histogram_quantile(0.1, histogram_quantile_2)
+    {} -13.6
+
+eval instant at 10m histogram_quantile(0, histogram_quantile_2)
+    {} -16
+
+eval instant at 10m histogram_quantile(-1, histogram_quantile_2)
+    {} -Inf
+
+# Apply quantile function to histogram with both positive and negative buckets with zero bucket.
+load 10m
+    histogram_quantile_3 {{schema:0 count:24 sum:100 z_bucket:4 z_bucket_w:0.001 buckets:[2 3 0 1 4] n_buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_quantile(1.001, histogram_quantile_3)
+    {} Inf
+
+eval instant at 10m histogram_quantile(1, histogram_quantile_3)
+    {} 16
+
+eval instant at 10m histogram_quantile(0.99, histogram_quantile_3)
+    {} 15.519999999999996
+
+eval instant at 10m histogram_quantile(0.9, histogram_quantile_3)
+    {} 11.200000000000003
+
+eval instant at 10m histogram_quantile(0.7, histogram_quantile_3)
+    {} 1.2666666666666657
+
+eval instant at 10m histogram_quantile(0.55, histogram_quantile_3)
+    {} 0.0006000000000000005
+
+eval instant at 10m histogram_quantile(0.5, histogram_quantile_3)
+    {} 0
+
+eval instant at 10m histogram_quantile(0.45, histogram_quantile_3)
+    {} -0.0005999999999999996
+
+eval instant at 10m histogram_quantile(0.3, histogram_quantile_3)
+    {} -1.266666666666667
+
+eval instant at 10m histogram_quantile(0.1, histogram_quantile_3)
+    {} -11.2
+
+eval instant at 10m histogram_quantile(0.01, histogram_quantile_3)
+    {} -15.52
+
+eval instant at 10m histogram_quantile(0, histogram_quantile_3)
+    {} -16
+
+eval instant at 10m histogram_quantile(-1, histogram_quantile_3)
+    {} -Inf
+
+# Apply fraction function to empty histogram.
+load 10m
+    histogram_fraction_1 {{}}x1
+
+eval instant at 10m histogram_fraction(3.1415, 42, histogram_fraction_1)
+    {} NaN
+
+# Apply fraction function to histogram with positive and zero buckets.
+load 10m
+    histogram_fraction_2 {{schema:0 count:12 sum:100 z_bucket:2 z_bucket_w:0.001 buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_fraction(0, +Inf, histogram_fraction_2)
+    {} 1
+
+eval instant at 10m histogram_fraction(-Inf, 0, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(-0.001, 0, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(0, 0.001, histogram_fraction_2)
+    {} 0.16666666666666666
+
+eval instant at 10m histogram_fraction(0, 0.0005, histogram_fraction_2)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(0.001, inf, histogram_fraction_2)
+    {} 0.8333333333333334
+
+eval instant at 10m histogram_fraction(-inf, -0.001, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(1, 2, histogram_fraction_2)
+    {} 0.25
+
+eval instant at 10m histogram_fraction(1.5, 2, histogram_fraction_2)
+    {} 0.125
+
+eval instant at 10m histogram_fraction(1, 8, histogram_fraction_2)
+    {} 0.3333333333333333
+
+eval instant at 10m histogram_fraction(1, 6, histogram_fraction_2)
+    {} 0.2916666666666667
+
+eval instant at 10m histogram_fraction(1.5, 6, histogram_fraction_2)
+    {} 0.16666666666666666
+
+eval instant at 10m histogram_fraction(-2, -1, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(-2, -1.5, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(-8, -1, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(-6, -1, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(-6, -1.5, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(42, 3.1415, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(0, 0, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(0.000001, 0.000001, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(42, 42, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(-3.1, -3.1, histogram_fraction_2)
+    {} 0
+
+eval instant at 10m histogram_fraction(3.1415, NaN, histogram_fraction_2)
+    {} NaN
+
+eval instant at 10m histogram_fraction(NaN, 42, histogram_fraction_2)
+    {} NaN
+
+eval instant at 10m histogram_fraction(NaN, NaN, histogram_fraction_2)
+    {} NaN
+
+eval instant at 10m histogram_fraction(-Inf, +Inf, histogram_fraction_2)
+    {} 1
+
+# Apply fraction function to histogram with negative and zero buckets.
+load 10m
+    histogram_fraction_3 {{schema:0 count:12 sum:100 z_bucket:2 z_bucket_w:0.001 n_buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_fraction(0, +Inf, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(-Inf, 0, histogram_fraction_3)
+    {} 1
+
+eval instant at 10m histogram_fraction(-0.001, 0, histogram_fraction_3)
+    {} 0.16666666666666666
+
+eval instant at 10m histogram_fraction(0, 0.001, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(-0.0005, 0, histogram_fraction_3)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(0.001, inf, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(-inf, -0.001, histogram_fraction_3)
+    {} 0.8333333333333334
+
+eval instant at 10m histogram_fraction(1, 2, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(1.5, 2, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(1, 8, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(1, 6, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(1.5, 6, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(-2, -1, histogram_fraction_3)
+    {} 0.25
+
+eval instant at 10m histogram_fraction(-2, -1.5, histogram_fraction_3)
+    {} 0.125
+
+eval instant at 10m histogram_fraction(-8, -1, histogram_fraction_3)
+    {} 0.3333333333333333
+
+eval instant at 10m histogram_fraction(-6, -1, histogram_fraction_3)
+    {} 0.2916666666666667
+
+eval instant at 10m histogram_fraction(-6, -1.5, histogram_fraction_3)
+    {} 0.16666666666666666
+
+eval instant at 10m histogram_fraction(42, 3.1415, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(0, 0, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(0.000001, 0.000001, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(42, 42, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(-3.1, -3.1, histogram_fraction_3)
+    {} 0
+
+eval instant at 10m histogram_fraction(3.1415, NaN, histogram_fraction_3)
+    {} NaN
+
+eval instant at 10m histogram_fraction(NaN, 42, histogram_fraction_3)
+    {} NaN
+
+eval instant at 10m histogram_fraction(NaN, NaN, histogram_fraction_3)
+    {} NaN
+
+eval instant at 10m histogram_fraction(-Inf, +Inf, histogram_fraction_3)
+    {} 1
+
+# Apply fraction function to histogram with both positive, negative and zero buckets.
+load 10m
+    histogram_fraction_4 {{schema:0 count:24 sum:100 z_bucket:4 z_bucket_w:0.001 buckets:[2 3 0 1 4] n_buckets:[2 3 0 1 4]}}x1
+
+eval instant at 10m histogram_fraction(0, +Inf, histogram_fraction_4)
+    {} 0.5
+
+eval instant at 10m histogram_fraction(-Inf, 0, histogram_fraction_4)
+    {} 0.5
+
+eval instant at 10m histogram_fraction(-0.001, 0, histogram_fraction_4)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(0, 0.001, histogram_fraction_4)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(-0.0005, 0.0005, histogram_fraction_4)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(0.001, inf, histogram_fraction_4)
+    {} 0.4166666666666667
+
+eval instant at 10m histogram_fraction(-inf, -0.001, histogram_fraction_4)
+    {} 0.4166666666666667
+
+eval instant at 10m histogram_fraction(1, 2, histogram_fraction_4)
+    {} 0.125
+
+eval instant at 10m histogram_fraction(1.5, 2, histogram_fraction_4)
+    {} 0.0625
+
+eval instant at 10m histogram_fraction(1, 8, histogram_fraction_4)
+    {} 0.16666666666666666
+
+eval instant at 10m histogram_fraction(1, 6, histogram_fraction_4)
+    {} 0.14583333333333334
+
+eval instant at 10m histogram_fraction(1.5, 6, histogram_fraction_4)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(-2, -1, histogram_fraction_4)
+    {} 0.125
+
+eval instant at 10m histogram_fraction(-2, -1.5, histogram_fraction_4)
+    {} 0.0625
+
+eval instant at 10m histogram_fraction(-8, -1, histogram_fraction_4)
+    {} 0.16666666666666666
+
+eval instant at 10m histogram_fraction(-6, -1, histogram_fraction_4)
+    {} 0.14583333333333334
+
+eval instant at 10m histogram_fraction(-6, -1.5, histogram_fraction_4)
+    {} 0.08333333333333333
+
+eval instant at 10m histogram_fraction(42, 3.1415, histogram_fraction_4)
+    {} 0
+
+eval instant at 10m histogram_fraction(0, 0, histogram_fraction_4)
+    {} 0
+
+eval instant at 10m histogram_fraction(0.000001, 0.000001, histogram_fraction_4)
+    {} 0
+
+eval instant at 10m histogram_fraction(42, 42, histogram_fraction_4)
+    {} 0
+
+eval instant at 10m histogram_fraction(-3.1, -3.1, histogram_fraction_4)
+    {} 0
+
+eval instant at 10m histogram_fraction(3.1415, NaN, histogram_fraction_4)
+    {} NaN
+
+eval instant at 10m histogram_fraction(NaN, 42, histogram_fraction_4)
+    {} NaN
+
+eval instant at 10m histogram_fraction(NaN, NaN, histogram_fraction_4)
+    {} NaN
+
+eval instant at 10m histogram_fraction(-Inf, +Inf, histogram_fraction_4)
+    {} 1

rules/manager_test.go

@@ -19,6 +19,7 @@ import (
 	"math"
 	"os"
 	"sort"
+	"strconv"
 	"sync"
 	"testing"
 	"time"
@@ -1361,7 +1362,7 @@ func TestNativeHistogramsInRecordingRules(t *testing.T) {
 	ts := time.Now()
 	app := db.Appender(context.Background())
 	for i, h := range hists {
-		l := labels.FromStrings("__name__", "histogram_metric", "idx", fmt.Sprintf("%d", i))
+		l := labels.FromStrings("__name__", "histogram_metric", "idx", strconv.Itoa(i))
 		_, err := app.AppendHistogram(0, l, ts.UnixMilli(), h.Copy(), nil)
 		require.NoError(t, err)
 	}
@@ -2043,7 +2044,7 @@ func TestBoundedRuleEvalConcurrency(t *testing.T) {
 	require.EqualValues(t, maxInflight.Load(), int32(maxConcurrency)+int32(groupCount))
 }
 
-const artificialDelay = 10 * time.Millisecond
+const artificialDelay = 15 * time.Millisecond
 
 func optsFactory(storage storage.Storage, maxInflight, inflightQueries *atomic.Int32, maxConcurrent int64) *ManagerOptions {
 	var inflightMu sync.Mutex

scrape/scrape_test.go

@@ -1285,7 +1285,7 @@ func TestScrapeLoopCacheMemoryExhaustionProtection(t *testing.T) {
 			for i := 0; i < 500; i++ {
 				s = fmt.Sprintf("%smetric_%d_%d 42\n", s, i, numScrapes)
 			}
-			w.Write([]byte(fmt.Sprintf(s + "&")))
+			w.Write([]byte(s + "&"))
 		} else {
 			cancel()
 		}

scrape/target_test.go

@@ -21,6 +21,7 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"os"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -67,7 +68,7 @@ func TestTargetOffset(t *testing.T) {
 	// Calculate offsets for 10000 different targets.
 	for i := range offsets {
 		target := newTestTarget("example.com:80", 0, labels.FromStrings(
-			"label", fmt.Sprintf("%d", i),
+			"label", strconv.Itoa(i),
 		))
 		offsets[i] = target.offset(interval, offsetSeed)
 	}

storage/remote/azuread/azuread.go

@@ -75,7 +75,7 @@ type AzureADConfig struct { //nolint:revive // exported.
 	// OAuth is the oauth config that is being used to authenticate.
 	OAuth *OAuthConfig `yaml:"oauth,omitempty"`
 
-	// OAuth is the oauth config that is being used to authenticate.
+	// SDK is the SDK config that is being used to authenticate.
 	SDK *SDKConfig `yaml:"sdk,omitempty"`
 
 	// Cloud is the Azure cloud in which the service is running. Example: AzurePublic/AzureGovernment/AzureChina.

storage/remote/otlptranslator/prometheus/normalize_label.go

@@ -19,15 +19,6 @@ package prometheus
 import (
 	"strings"
 	"unicode"
-
-	"go.opentelemetry.io/collector/featuregate"
-)
-
-var dropSanitizationGate = featuregate.GlobalRegistry().MustRegister(
-	"pkg.translator.prometheus.PermissiveLabelSanitization",
-	featuregate.StageAlpha,
-	featuregate.WithRegisterDescription("Controls whether to change labels starting with '_' to 'key_'."),
-	featuregate.WithRegisterReferenceURL("https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/8950"),
 )
 
 // Normalizes the specified label to follow Prometheus label names standard
@@ -50,7 +41,7 @@ func NormalizeLabel(label string) string {
 	// If label starts with a number, prepend with "key_"
 	if unicode.IsDigit(rune(label[0])) {
 		label = "key_" + label
-	} else if strings.HasPrefix(label, "_") && !strings.HasPrefix(label, "__") && !dropSanitizationGate.IsEnabled() {
+	} else if strings.HasPrefix(label, "_") && !strings.HasPrefix(label, "__") {
 		label = "key" + label
 	}
 

storage/remote/otlptranslator/prometheus/normalize_name.go

@@ -20,7 +20,6 @@ import (
 	"strings"
 	"unicode"
 
-	"go.opentelemetry.io/collector/featuregate"
 	"go.opentelemetry.io/collector/pdata/pmetric"
 )
 
@@ -78,13 +77,6 @@ var perUnitMap = map[string]string{
 	"y":  "year",
 }
 
-var normalizeNameGate = featuregate.GlobalRegistry().MustRegister(
-	"pkg.translator.prometheus.NormalizeName",
-	featuregate.StageBeta,
-	featuregate.WithRegisterDescription("Controls whether metrics names are automatically normalized to follow Prometheus naming convention"),
-	featuregate.WithRegisterReferenceURL("https://github.com/open-telemetry/opentelemetry-collector-contrib/issues/8950"),
-)
-
 // BuildCompliantName builds a Prometheus-compliant metric name for the specified metric
 //
 // Metric name is prefixed with specified namespace and underscore (if any).
@@ -97,7 +89,7 @@ func BuildCompliantName(metric pmetric.Metric, namespace string, addMetricSuffix
 	var metricName string
 
 	// Full normalization following standard Prometheus naming conventions
-	if addMetricSuffixes && normalizeNameGate.IsEnabled() {
+	if addMetricSuffixes {
 		return normalizeName(metric, namespace)
 	}
 

storage/remote/queue_manager_test.go

@@ -468,7 +468,7 @@ func TestReleaseNoninternedString(t *testing.T) {
 		m.StoreSeries([]record.RefSeries{
 			{
 				Ref:    chunks.HeadSeriesRef(i),
-				Labels: labels.FromStrings("asdf", fmt.Sprintf("%d", i)),
+				Labels: labels.FromStrings("asdf", strconv.Itoa(i)),
 			},
 		}, 0)
 		m.SeriesReset(1)

tsdb/agent/series_test.go

@@ -14,8 +14,8 @@
 package agent
 
 import (
-	"fmt"
 	"math"
+	"strconv"
 	"sync"
 	"testing"
 	"time"
@@ -53,7 +53,7 @@ func TestNoDeadlock(t *testing.T) {
 			series := &memSeries{
 				ref: chunks.HeadSeriesRef(i),
 				lset: labels.FromMap(map[string]string{
-					"id": fmt.Sprintf("%d", i),
+					"id": strconv.Itoa(i),
 				}),
 			}
 			stripeSeries.Set(series.lset.Hash(), series)

tsdb/chunks/head_chunks.go

@@ -381,6 +381,33 @@ func listChunkFiles(dir string) (map[int]string, error) {
 	return res, nil
 }
 
+// HardLinkChunkFiles creates hardlinks for chunk files from src to dst.
+// It does nothing if src doesn't exist and ensures dst is created if not.
+func HardLinkChunkFiles(src, dst string) error {
+	_, err := os.Stat(src)
+	if os.IsNotExist(err) {
+		return nil
+	}
+	if err != nil {
+		return fmt.Errorf("check source chunks dir: %w", err)
+	}
+	if err := os.MkdirAll(dst, 0o777); err != nil {
+		return fmt.Errorf("set up destination chunks dir: %w", err)
+	}
+	files, err := listChunkFiles(src)
+	if err != nil {
+		return fmt.Errorf("list chunks: %w", err)
+	}
+	for _, filePath := range files {
+		_, fileName := filepath.Split(filePath)
+		err := os.Link(filepath.Join(src, fileName), filepath.Join(dst, fileName))
+		if err != nil {
+			return fmt.Errorf("hardlink a chunk: %w", err)
+		}
+	}
+	return nil
+}
+
 // repairLastChunkFile deletes the last file if it's empty.
 // Because we don't fsync when creating these files, we could end
 // up with an empty file at the end during an abrupt shutdown.

tsdb/compact_test.go

@@ -22,6 +22,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"strconv"
 	"sync"
 	"testing"
 	"time"
@@ -1129,7 +1130,7 @@ func BenchmarkCompactionFromHead(b *testing.B) {
 			for ln := 0; ln < labelNames; ln++ {
 				app := h.Appender(context.Background())
 				for lv := 0; lv < labelValues; lv++ {
-					app.Append(0, labels.FromStrings(fmt.Sprintf("%d", ln), fmt.Sprintf("%d%s%d", lv, postingsBenchSuffix, ln)), 0, 0)
+					app.Append(0, labels.FromStrings(strconv.Itoa(ln), fmt.Sprintf("%d%s%d", lv, postingsBenchSuffix, ln)), 0, 0)
 				}
 				require.NoError(b, app.Commit())
 			}
@@ -1161,7 +1162,7 @@ func BenchmarkCompactionFromOOOHead(b *testing.B) {
 			for ln := 0; ln < labelNames; ln++ {
 				app := h.Appender(context.Background())
 				for lv := 0; lv < labelValues; lv++ {
-					lbls := labels.FromStrings(fmt.Sprintf("%d", ln), fmt.Sprintf("%d%s%d", lv, postingsBenchSuffix, ln))
+					lbls := labels.FromStrings(strconv.Itoa(ln), fmt.Sprintf("%d%s%d", lv, postingsBenchSuffix, ln))
 					_, err = app.Append(0, lbls, int64(totalSamples), 0)
 					require.NoError(b, err)
 					for ts := 0; ts < totalSamples; ts++ {
@@ -1297,7 +1298,7 @@ func TestCancelCompactions(t *testing.T) {
 		// This checks that the `context.Canceled` error is properly checked at all levels:
 		// - tsdb_errors.NewMulti() should have the Is() method implemented for correct checks.
 		// - callers should check with errors.Is() instead of ==.
-		readOnlyDB, err := OpenDBReadOnly(tmpdirCopy, log.NewNopLogger())
+		readOnlyDB, err := OpenDBReadOnly(tmpdirCopy, "", log.NewNopLogger())
 		require.NoError(t, err)
 		blocks, err := readOnlyDB.Blocks()
 		require.NoError(t, err)

tsdb/db.go

@@ -383,26 +383,36 @@ var ErrClosed = errors.New("db already closed")
 // Current implementation doesn't support concurrency so
 // all API calls should happen in the same go routine.
 type DBReadOnly struct {
-	logger  log.Logger
+	logger     log.Logger
-	dir     string
+	dir        string
-	closers []io.Closer
+	sandboxDir string
-	closed  chan struct{}
+	closers    []io.Closer
+	closed     chan struct{}
 }
 
 // OpenDBReadOnly opens DB in the given directory for read only operations.
-func OpenDBReadOnly(dir string, l log.Logger) (*DBReadOnly, error) {
+func OpenDBReadOnly(dir, sandboxDirRoot string, l log.Logger) (*DBReadOnly, error) {
 	if _, err := os.Stat(dir); err != nil {
 		return nil, fmt.Errorf("opening the db dir: %w", err)
 	}
 
+	if sandboxDirRoot == "" {
+		sandboxDirRoot = dir
+	}
+	sandboxDir, err := os.MkdirTemp(sandboxDirRoot, "tmp_dbro_sandbox")
+	if err != nil {
+		return nil, fmt.Errorf("setting up sandbox dir: %w", err)
+	}
+
 	if l == nil {
 		l = log.NewNopLogger()
 	}
 
 	return &DBReadOnly{
-		logger: l,
+		logger:     l,
-		dir:    dir,
+		dir:        dir,
-		closed: make(chan struct{}),
+		sandboxDir: sandboxDir,
+		closed:     make(chan struct{}),
 	}, nil
 }
 
@@ -491,7 +501,14 @@ func (db *DBReadOnly) loadDataAsQueryable(maxt int64) (storage.SampleAndChunkQue
 	}
 
 	opts := DefaultHeadOptions()
-	opts.ChunkDirRoot = db.dir
+	// Hard link the chunk files to a dir in db.sandboxDir in case the Head needs to truncate some of them
+	// or cut new ones while replaying the WAL.
+	// See https://github.com/prometheus/prometheus/issues/11618.
+	err = chunks.HardLinkChunkFiles(mmappedChunksDir(db.dir), mmappedChunksDir(db.sandboxDir))
+	if err != nil {
+		return nil, err
+	}
+	opts.ChunkDirRoot = db.sandboxDir
 	head, err := NewHead(nil, db.logger, nil, nil, opts, NewHeadStats())
 	if err != nil {
 		return nil, err
@@ -519,7 +536,7 @@ func (db *DBReadOnly) loadDataAsQueryable(maxt int64) (storage.SampleAndChunkQue
 			}
 		}
 		opts := DefaultHeadOptions()
-		opts.ChunkDirRoot = db.dir
+		opts.ChunkDirRoot = db.sandboxDir
 		head, err = NewHead(nil, db.logger, w, wbl, opts, NewHeadStats())
 		if err != nil {
 			return nil, err
@@ -690,8 +707,14 @@ func (db *DBReadOnly) Block(blockID string) (BlockReader, error) {
 	return block, nil
 }
 
-// Close all block readers.
+// Close all block readers and delete the sandbox dir.
 func (db *DBReadOnly) Close() error {
+	defer func() {
+		// Delete the temporary sandbox directory that was created when opening the DB.
+		if err := os.RemoveAll(db.sandboxDir); err != nil {
+			level.Error(db.logger).Log("msg", "delete sandbox dir", "err", err)
+		}
+	}()
 	select {
 	case <-db.closed:
 		return ErrClosed

tsdb/db_test.go

@@ -25,6 +25,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"runtime"
 	"sort"
 	"strconv"
 	"sync"
@@ -1065,7 +1066,7 @@ func TestWALSegmentSizeOptions(t *testing.T) {
 
 			for i := int64(0); i < 155; i++ {
 				app := db.Appender(context.Background())
-				ref, err := app.Append(0, labels.FromStrings("wal"+fmt.Sprintf("%d", i), "size"), i, rand.Float64())
+				ref, err := app.Append(0, labels.FromStrings("wal"+strconv.Itoa(int(i)), "size"), i, rand.Float64())
 				require.NoError(t, err)
 				for j := int64(1); j <= 78; j++ {
 					_, err := app.Append(ref, labels.EmptyLabels(), i+j, rand.Float64())
@@ -2494,7 +2495,7 @@ func TestDBReadOnly(t *testing.T) {
 	}
 
 	// Open a read only db and ensure that the API returns the same result as the normal DB.
-	dbReadOnly, err := OpenDBReadOnly(dbDir, logger)
+	dbReadOnly, err := OpenDBReadOnly(dbDir, "", logger)
 	require.NoError(t, err)
 	defer func() { require.NoError(t, dbReadOnly.Close()) }()
 
@@ -2548,10 +2549,14 @@ func TestDBReadOnly(t *testing.T) {
 // TestDBReadOnlyClosing ensures that after closing the db
 // all api methods return an ErrClosed.
 func TestDBReadOnlyClosing(t *testing.T) {
-	dbDir := t.TempDir()
+	sandboxDir := t.TempDir()
-	db, err := OpenDBReadOnly(dbDir, log.NewLogfmtLogger(log.NewSyncWriter(os.Stderr)))
+	db, err := OpenDBReadOnly(t.TempDir(), sandboxDir, log.NewLogfmtLogger(log.NewSyncWriter(os.Stderr)))
 	require.NoError(t, err)
+	// The sandboxDir was there.
+	require.DirExists(t, db.sandboxDir)
 	require.NoError(t, db.Close())
+	// The sandboxDir was deleted when closing.
+	require.NoDirExists(t, db.sandboxDir)
 	require.Equal(t, db.Close(), ErrClosed)
 	_, err = db.Blocks()
 	require.Equal(t, err, ErrClosed)
@@ -2587,7 +2592,7 @@ func TestDBReadOnly_FlushWAL(t *testing.T) {
 	}
 
 	// Flush WAL.
-	db, err := OpenDBReadOnly(dbDir, logger)
+	db, err := OpenDBReadOnly(dbDir, "", logger)
 	require.NoError(t, err)
 
 	flush := t.TempDir()
@@ -2595,7 +2600,7 @@ func TestDBReadOnly_FlushWAL(t *testing.T) {
 	require.NoError(t, db.Close())
 
 	// Reopen the DB from the flushed WAL block.
-	db, err = OpenDBReadOnly(flush, logger)
+	db, err = OpenDBReadOnly(flush, "", logger)
 	require.NoError(t, err)
 	defer func() { require.NoError(t, db.Close()) }()
 	blocks, err := db.Blocks()
@@ -2624,6 +2629,80 @@ func TestDBReadOnly_FlushWAL(t *testing.T) {
 	require.Equal(t, 1000.0, sum)
 }
 
+func TestDBReadOnly_Querier_NoAlteration(t *testing.T) {
+	countChunks := func(dir string) int {
+		files, err := os.ReadDir(mmappedChunksDir(dir))
+		require.NoError(t, err)
+		return len(files)
+	}
+
+	dirHash := func(dir string) (hash []byte) {
+		// Windows requires the DB to be closed: "xxx\lock: The process cannot access the file because it is being used by another process."
+		// But closing the DB alters the directory in this case (it'll cut a new chunk).
+		if runtime.GOOS != "windows" {
+			hash = testutil.DirHash(t, dir)
+		}
+		return
+	}
+
+	spinUpQuerierAndCheck := func(dir, sandboxDir string, chunksCount int) {
+		dBDirHash := dirHash(dir)
+		// Bootsrap a RO db from the same dir and set up a querier.
+		dbReadOnly, err := OpenDBReadOnly(dir, sandboxDir, nil)
+		require.NoError(t, err)
+		require.Equal(t, chunksCount, countChunks(dir))
+		q, err := dbReadOnly.Querier(math.MinInt, math.MaxInt)
+		require.NoError(t, err)
+		require.NoError(t, q.Close())
+		require.NoError(t, dbReadOnly.Close())
+		// The RO Head doesn't alter RW db chunks_head/.
+		require.Equal(t, chunksCount, countChunks(dir))
+		require.Equal(t, dirHash(dir), dBDirHash)
+	}
+
+	t.Run("doesn't cut chunks while replaying WAL", func(t *testing.T) {
+		db := openTestDB(t, nil, nil)
+		defer func() {
+			require.NoError(t, db.Close())
+		}()
+
+		// Append until the first mmaped head chunk.
+		for i := 0; i < 121; i++ {
+			app := db.Appender(context.Background())
+			_, err := app.Append(0, labels.FromStrings("foo", "bar"), int64(i), 0)
+			require.NoError(t, err)
+			require.NoError(t, app.Commit())
+		}
+
+		spinUpQuerierAndCheck(db.dir, t.TempDir(), 0)
+
+		// The RW Head should have no problem cutting its own chunk,
+		// this also proves that a chunk needed to be cut.
+		require.NotPanics(t, func() { db.ForceHeadMMap() })
+		require.Equal(t, 1, countChunks(db.dir))
+	})
+
+	t.Run("doesn't truncate corrupted chunks", func(t *testing.T) {
+		db := openTestDB(t, nil, nil)
+		require.NoError(t, db.Close())
+
+		// Simulate a corrupted chunk: without a header.
+		_, err := os.Create(path.Join(mmappedChunksDir(db.dir), "000001"))
+		require.NoError(t, err)
+
+		spinUpQuerierAndCheck(db.dir, t.TempDir(), 1)
+
+		// The RW Head should have no problem truncating its corrupted file:
+		// this proves that the chunk needed to be truncated.
+		db, err = Open(db.dir, nil, nil, nil, nil)
+		defer func() {
+			require.NoError(t, db.Close())
+		}()
+		require.NoError(t, err)
+		require.Equal(t, 0, countChunks(db.dir))
+	})
+}
+
 func TestDBCannotSeePartialCommits(t *testing.T) {
 	if defaultIsolationDisabled {
 		t.Skip("skipping test since tsdb isolation is disabled")

tsdb/exemplar_test.go

@@ -416,7 +416,7 @@ func BenchmarkAddExemplar(b *testing.B) {
 	exLabels := labels.FromStrings("trace_id", "89620921")
 
 	for _, n := range []int{10000, 100000, 1000000} {
-		b.Run(fmt.Sprintf("%d", n), func(b *testing.B) {
+		b.Run(strconv.Itoa(n), func(b *testing.B) {
 			for j := 0; j < b.N; j++ {
 				b.StopTimer()
 				exs, err := NewCircularExemplarStorage(int64(n), eMetrics)

tsdb/head.go

@@ -310,12 +310,22 @@ func (h *Head) resetInMemoryState() error {
 		return err
 	}
 
+	if h.series != nil {
+		// reset the existing series to make sure we call the appropriated hooks
+		// and increment the series removed metrics
+		fs := h.series.iterForDeletion(func(_ int, _ uint64, s *memSeries, flushedForCallback map[chunks.HeadSeriesRef]labels.Labels) {
+			// All series should be flushed
+			flushedForCallback[s.ref] = s.lset
+		})
+		h.metrics.seriesRemoved.Add(float64(fs))
+	}
+
+	h.series = newStripeSeries(h.opts.StripeSize, h.opts.SeriesCallback)
 	h.iso = newIsolation(h.opts.IsolationDisabled)
 	h.oooIso = newOOOIsolation()
-
+	h.numSeries.Store(0)
 	h.exemplarMetrics = em
 	h.exemplars = es
-	h.series = newStripeSeries(h.opts.StripeSize, h.opts.SeriesCallback)
 	h.postings = index.NewUnorderedMemPostings()
 	h.tombstones = tombstones.NewMemTombstones()
 	h.deleted = map[chunks.HeadSeriesRef]int{}
@@ -1861,11 +1871,10 @@ func newStripeSeries(stripeSize int, seriesCallback SeriesLifecycleCallback) *st
 // minMmapFile is the min mmap file number seen in the series (in-order and out-of-order) after gc'ing the series.
 func (s *stripeSeries) gc(mint int64, minOOOMmapRef chunks.ChunkDiskMapperRef) (_ map[storage.SeriesRef]struct{}, _ int, _, _ int64, minMmapFile int) {
 	var (
-		deleted                     = map[storage.SeriesRef]struct{}{}
+		deleted          = map[storage.SeriesRef]struct{}{}
-		rmChunks                    = 0
+		rmChunks         = 0
-		actualMint            int64 = math.MaxInt64
+		actualMint int64 = math.MaxInt64
-		minOOOTime            int64 = math.MaxInt64
+		minOOOTime int64 = math.MaxInt64
-		deletedFromPrevStripe       = 0
 	)
 	minMmapFile = math.MaxInt32
 
@@ -1923,27 +1932,7 @@ func (s *stripeSeries) gc(mint int64, minOOOMmapRef chunks.ChunkDiskMapperRef) (
 		deletedForCallback[series.ref] = series.lset
 	}
 
-	// Run through all series shard by shard, checking which should be deleted.
+	s.iterForDeletion(check)
-	for i := 0; i < s.size; i++ {
-		deletedForCallback := make(map[chunks.HeadSeriesRef]labels.Labels, deletedFromPrevStripe)
-		s.locks[i].Lock()
-
-		// Delete conflicts first so seriesHashmap.del doesn't move them to the `unique` field,
-		// after deleting `unique`.
-		for hash, all := range s.hashes[i].conflicts {
-			for _, series := range all {
-				check(i, hash, series, deletedForCallback)
-			}
-		}
-		for hash, series := range s.hashes[i].unique {
-			check(i, hash, series, deletedForCallback)
-		}
-
-		s.locks[i].Unlock()
-
-		s.seriesLifecycleCallback.PostDeletion(deletedForCallback)
-		deletedFromPrevStripe = len(deletedForCallback)
-	}
 
 	if actualMint == math.MaxInt64 {
 		actualMint = mint
@@ -1952,6 +1941,35 @@ func (s *stripeSeries) gc(mint int64, minOOOMmapRef chunks.ChunkDiskMapperRef) (
 	return deleted, rmChunks, actualMint, minOOOTime, minMmapFile
 }
 
+// The iterForDeletion function iterates through all series, invoking the checkDeletedFunc for each.
+// The checkDeletedFunc takes a map as input and should add to it all series that were deleted and should be included
+// when invoking the PostDeletion hook.
+func (s *stripeSeries) iterForDeletion(checkDeletedFunc func(int, uint64, *memSeries, map[chunks.HeadSeriesRef]labels.Labels)) int {
+	seriesSetFromPrevStripe := 0
+	totalDeletedSeries := 0
+	// Run through all series shard by shard
+	for i := 0; i < s.size; i++ {
+		seriesSet := make(map[chunks.HeadSeriesRef]labels.Labels, seriesSetFromPrevStripe)
+		s.locks[i].Lock()
+		// Iterate conflicts first so f doesn't move them to the `unique` field,
+		// after deleting `unique`.
+		for hash, all := range s.hashes[i].conflicts {
+			for _, series := range all {
+				checkDeletedFunc(i, hash, series, seriesSet)
+			}
+		}
+
+		for hash, series := range s.hashes[i].unique {
+			checkDeletedFunc(i, hash, series, seriesSet)
+		}
+		s.locks[i].Unlock()
+		s.seriesLifecycleCallback.PostDeletion(seriesSet)
+		totalDeletedSeries += len(seriesSet)
+		seriesSetFromPrevStripe = len(seriesSet)
+	}
+	return totalDeletedSeries
+}
+
 func (s *stripeSeries) getByID(id chunks.HeadSeriesRef) *memSeries {
 	i := uint64(id) & uint64(s.size-1)
 

tsdb/head_test.go

@@ -3383,7 +3383,7 @@ func TestWaitForPendingReadersInTimeRange(t *testing.T) {
 func TestAppendHistogram(t *testing.T) {
 	l := labels.FromStrings("a", "b")
 	for _, numHistograms := range []int{1, 10, 150, 200, 250, 300} {
-		t.Run(fmt.Sprintf("%d", numHistograms), func(t *testing.T) {
+		t.Run(strconv.Itoa(numHistograms), func(t *testing.T) {
 			head, _ := newTestHead(t, 1000, wlog.CompressionNone, false)
 			t.Cleanup(func() {
 				require.NoError(t, head.Close())
@@ -3692,7 +3692,7 @@ func TestChunkSnapshot(t *testing.T) {
 		e := ex{
 			seriesLabels: lbls,
 			e: exemplar.Exemplar{
-				Labels: labels.FromStrings("trace_id", fmt.Sprintf("%d", rand.Int())),
+				Labels: labels.FromStrings("trace_id", strconv.Itoa(rand.Int())),
 				Value:  rand.Float64(),
 				Ts:     ts,
 			},
@@ -4007,6 +4007,9 @@ func TestSnapshotError(t *testing.T) {
 	require.NoError(t, err)
 	f, err := os.OpenFile(path.Join(snapDir, files[0].Name()), os.O_RDWR, 0)
 	require.NoError(t, err)
+	// Create snapshot backup to be restored on future test cases.
+	snapshotBackup, err := io.ReadAll(f)
+	require.NoError(t, err)
 	_, err = f.WriteAt([]byte{0b11111111}, 18)
 	require.NoError(t, err)
 	require.NoError(t, f.Close())
@@ -4021,10 +4024,44 @@ func TestSnapshotError(t *testing.T) {
 
 	// There should be no series in the memory after snapshot error since WAL was removed.
 	require.Equal(t, 1.0, prom_testutil.ToFloat64(head.metrics.snapshotReplayErrorTotal))
+	require.Equal(t, uint64(0), head.NumSeries())
 	require.Nil(t, head.series.getByHash(lbls.Hash(), lbls))
 	tm, err = head.tombstones.Get(1)
 	require.NoError(t, err)
 	require.Empty(t, tm)
+	require.NoError(t, head.Close())
+
+	// Test corruption in the middle of the snapshot.
+	f, err = os.OpenFile(path.Join(snapDir, files[0].Name()), os.O_RDWR, 0)
+	require.NoError(t, err)
+	_, err = f.WriteAt(snapshotBackup, 0)
+	require.NoError(t, err)
+	_, err = f.WriteAt([]byte{0b11111111}, 300)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+
+	c := &countSeriesLifecycleCallback{}
+	opts := head.opts
+	opts.SeriesCallback = c
+
+	w, err = wlog.NewSize(nil, nil, head.wal.Dir(), 32768, wlog.CompressionNone)
+	require.NoError(t, err)
+	head, err = NewHead(prometheus.NewRegistry(), nil, w, nil, head.opts, nil)
+	require.NoError(t, err)
+	require.NoError(t, head.Init(math.MinInt64))
+
+	// There should be no series in the memory after snapshot error since WAL was removed.
+	require.Equal(t, 1.0, prom_testutil.ToFloat64(head.metrics.snapshotReplayErrorTotal))
+	require.Nil(t, head.series.getByHash(lbls.Hash(), lbls))
+	require.Equal(t, uint64(0), head.NumSeries())
+
+	// Since the snapshot could replay certain series, we continue invoking the create hooks.
+	// In such instances, we need to ensure that we also trigger the delete hooks when resetting the memory.
+	require.Equal(t, int64(2), c.created.Load())
+	require.Equal(t, int64(2), c.deleted.Load())
+
+	require.Equal(t, 2.0, prom_testutil.ToFloat64(head.metrics.seriesRemoved))
+	require.Equal(t, 2.0, prom_testutil.ToFloat64(head.metrics.seriesCreated))
 }
 
 func TestHistogramMetrics(t *testing.T) {
@@ -5032,7 +5069,7 @@ func TestOOOAppendWithNoSeries(t *testing.T) {
 		require.Equal(t, expSamples, ms.headChunks.chunk.NumSamples())
 	}
 
-	newLabels := func(idx int) labels.Labels { return labels.FromStrings("foo", fmt.Sprintf("%d", idx)) }
+	newLabels := func(idx int) labels.Labels { return labels.FromStrings("foo", strconv.Itoa(idx)) }
 
 	s1 := newLabels(1)
 	appendSample(s1, 300) // At 300m.
@@ -5829,3 +5866,14 @@ func TestHeadCompactableDoesNotCompactEmptyHead(t *testing.T) {
 
 	require.False(t, head.compactable())
 }
+
+type countSeriesLifecycleCallback struct {
+	created atomic.Int64
+	deleted atomic.Int64
+}
+
+func (c *countSeriesLifecycleCallback) PreCreation(labels.Labels) error { return nil }
+func (c *countSeriesLifecycleCallback) PostCreation(labels.Labels)      { c.created.Inc() }
+func (c *countSeriesLifecycleCallback) PostDeletion(s map[chunks.HeadSeriesRef]labels.Labels) {
+	c.deleted.Add(int64(len(s)))
+}

tsdb/index/index.go

@@ -51,6 +51,9 @@ const (
 	indexFilename = "index"
 
 	seriesByteAlign = 16
+
+	// checkContextEveryNIterations is used in some tight loops to check if the context is done.
+	checkContextEveryNIterations = 128
 )
 
 type indexWriterSeries struct {
@@ -1797,7 +1800,12 @@ func (r *Reader) postingsForLabelMatchingV1(ctx context.Context, name string, ma
 	}
 
 	var its []Postings
+	count := 1
 	for val, offset := range e {
+		if count%checkContextEveryNIterations == 0 && ctx.Err() != nil {
+			return ErrPostings(ctx.Err())
+		}
+		count++
 		if !match(val) {
 			continue
 		}

tsdb/index/index_test.go

@@ -20,7 +20,9 @@ import (
 	"hash/crc32"
 	"os"
 	"path/filepath"
+	"slices"
 	"sort"
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -160,39 +162,14 @@ func TestIndexRW_Create_Open(t *testing.T) {
 }
 
 func TestIndexRW_Postings(t *testing.T) {
-	dir := t.TempDir()
 	ctx := context.Background()
-
+	var input indexWriterSeriesSlice
-	fn := filepath.Join(dir, indexFilename)
+	for i := 1; i < 5; i++ {
-
+		input = append(input, &indexWriterSeries{
-	iw, err := NewWriter(context.Background(), fn)
+			labels: labels.FromStrings("a", "1", "b", strconv.Itoa(i)),
-	require.NoError(t, err)
+		})
-
-	series := []labels.Labels{
-		labels.FromStrings("a", "1", "b", "1"),
-		labels.FromStrings("a", "1", "b", "2"),
-		labels.FromStrings("a", "1", "b", "3"),
-		labels.FromStrings("a", "1", "b", "4"),
 	}
-
+	ir, fn, _ := createFileReader(ctx, t, input)
-	require.NoError(t, iw.AddSymbol("1"))
-	require.NoError(t, iw.AddSymbol("2"))
-	require.NoError(t, iw.AddSymbol("3"))
-	require.NoError(t, iw.AddSymbol("4"))
-	require.NoError(t, iw.AddSymbol("a"))
-	require.NoError(t, iw.AddSymbol("b"))
-
-	// Postings lists are only written if a series with the respective
-	// reference was added before.
-	require.NoError(t, iw.AddSeries(1, series[0]))
-	require.NoError(t, iw.AddSeries(2, series[1]))
-	require.NoError(t, iw.AddSeries(3, series[2]))
-	require.NoError(t, iw.AddSeries(4, series[3]))
-
-	require.NoError(t, iw.Close())
-
-	ir, err := NewFileReader(fn)
-	require.NoError(t, err)
 
 	p, err := ir.Postings(ctx, "a", "1")
 	require.NoError(t, err)
@@ -205,7 +182,7 @@ func TestIndexRW_Postings(t *testing.T) {
 
 		require.NoError(t, err)
 		require.Empty(t, c)
-		testutil.RequireEqual(t, series[i], builder.Labels())
+		testutil.RequireEqual(t, input[i].labels, builder.Labels())
 	}
 	require.NoError(t, p.Err())
 
@@ -240,8 +217,6 @@ func TestIndexRW_Postings(t *testing.T) {
 		"b": {"1", "2", "3", "4"},
 	}, labelIndices)
 
-	require.NoError(t, ir.Close())
-
 	t.Run("ShardedPostings()", func(t *testing.T) {
 		ir, err := NewFileReader(fn)
 		require.NoError(t, err)
@@ -296,42 +271,16 @@ func TestIndexRW_Postings(t *testing.T) {
 }
 
 func TestPostingsMany(t *testing.T) {
-	dir := t.TempDir()
 	ctx := context.Background()
-
-	fn := filepath.Join(dir, indexFilename)
-
-	iw, err := NewWriter(context.Background(), fn)
-	require.NoError(t, err)
-
 	// Create a label in the index which has 999 values.
-	symbols := map[string]struct{}{}
+	var input indexWriterSeriesSlice
-	series := []labels.Labels{}
 	for i := 1; i < 1000; i++ {
 		v := fmt.Sprintf("%03d", i)
-		series = append(series, labels.FromStrings("i", v, "foo", "bar"))
+		input = append(input, &indexWriterSeries{
-		symbols[v] = struct{}{}
+			labels: labels.FromStrings("i", v, "foo", "bar"),
+		})
 	}
-	symbols["i"] = struct{}{}
+	ir, _, symbols := createFileReader(ctx, t, input)
-	symbols["foo"] = struct{}{}
-	symbols["bar"] = struct{}{}
-	syms := []string{}
-	for s := range symbols {
-		syms = append(syms, s)
-	}
-	sort.Strings(syms)
-	for _, s := range syms {
-		require.NoError(t, iw.AddSymbol(s))
-	}
-
-	for i, s := range series {
-		require.NoError(t, iw.AddSeries(storage.SeriesRef(i), s))
-	}
-	require.NoError(t, iw.Close())
-
-	ir, err := NewFileReader(fn)
-	require.NoError(t, err)
-	defer func() { require.NoError(t, ir.Close()) }()
 
 	cases := []struct {
 		in []string
@@ -387,25 +336,13 @@ func TestPostingsMany(t *testing.T) {
 }
 
 func TestPersistence_index_e2e(t *testing.T) {
-	dir := t.TempDir()
 	ctx := context.Background()
-
 	lbls, err := labels.ReadLabels(filepath.Join("..", "testdata", "20kseries.json"), 20000)
 	require.NoError(t, err)
-
 	// Sort labels as the index writer expects series in sorted order.
 	sort.Sort(labels.Slice(lbls))
 
-	symbols := map[string]struct{}{}
-	for _, lset := range lbls {
-		lset.Range(func(l labels.Label) {
-			symbols[l.Name] = struct{}{}
-			symbols[l.Value] = struct{}{}
-		})
-	}
-
 	var input indexWriterSeriesSlice
-
 	ref := uint64(0)
 	// Generate ChunkMetas for every label set.
 	for i, lset := range lbls {
@@ -426,17 +363,7 @@ func TestPersistence_index_e2e(t *testing.T) {
 		})
 	}
 
-	iw, err := NewWriter(context.Background(), filepath.Join(dir, indexFilename))
+	ir, _, _ := createFileReader(ctx, t, input)
-	require.NoError(t, err)
-
-	syms := []string{}
-	for s := range symbols {
-		syms = append(syms, s)
-	}
-	sort.Strings(syms)
-	for _, s := range syms {
-		require.NoError(t, iw.AddSymbol(s))
-	}
 
 	// Population procedure as done by compaction.
 	var (
@@ -447,8 +374,6 @@ func TestPersistence_index_e2e(t *testing.T) {
 	mi := newMockIndex()
 
 	for i, s := range input {
-		err = iw.AddSeries(storage.SeriesRef(i), s.labels, s.chunks...)
-		require.NoError(t, err)
 		require.NoError(t, mi.AddSeries(storage.SeriesRef(i), s.labels, s.chunks...))
 
 		s.labels.Range(func(l labels.Label) {
@@ -462,12 +387,6 @@ func TestPersistence_index_e2e(t *testing.T) {
 		postings.Add(storage.SeriesRef(i), s.labels)
 	}
 
-	err = iw.Close()
-	require.NoError(t, err)
-
-	ir, err := NewFileReader(filepath.Join(dir, indexFilename))
-	require.NoError(t, err)
-
 	for p := range mi.postings {
 		gotp, err := ir.Postings(ctx, p.Name, p.Value)
 		require.NoError(t, err)
@@ -523,8 +442,6 @@ func TestPersistence_index_e2e(t *testing.T) {
 	}
 	sort.Strings(expSymbols)
 	require.Equal(t, expSymbols, gotSymbols)
-
-	require.NoError(t, ir.Close())
 }
 
 func TestWriter_ShouldReturnErrorOnSeriesWithDuplicatedLabelNames(t *testing.T) {
@@ -624,39 +541,14 @@ func BenchmarkReader_ShardedPostings(b *testing.B) {
 		numShards = 16
 	)
 
-	dir, err := os.MkdirTemp("", "benchmark_reader_sharded_postings")
-	require.NoError(b, err)
-	defer func() {
-		require.NoError(b, os.RemoveAll(dir))
-	}()
-
 	ctx := context.Background()
-
+	var input indexWriterSeriesSlice
-	// Generate an index.
-	fn := filepath.Join(dir, indexFilename)
-
-	iw, err := NewWriter(ctx, fn)
-	require.NoError(b, err)
-
 	for i := 1; i <= numSeries; i++ {
-		require.NoError(b, iw.AddSymbol(fmt.Sprintf("%10d", i)))
+		input = append(input, &indexWriterSeries{
+			labels: labels.FromStrings("const", fmt.Sprintf("%10d", 1), "unique", fmt.Sprintf("%10d", i)),
+		})
 	}
-	require.NoError(b, iw.AddSymbol("const"))
+	ir, _, _ := createFileReader(ctx, b, input)
-	require.NoError(b, iw.AddSymbol("unique"))
-
-	for i := 1; i <= numSeries; i++ {
-		require.NoError(b, iw.AddSeries(storage.SeriesRef(i),
-			labels.FromStrings("const", fmt.Sprintf("%10d", 1), "unique", fmt.Sprintf("%10d", i))))
-	}
-
-	require.NoError(b, iw.Close())
-
-	b.ResetTimer()
-
-	// Create a reader to read back all postings from the index.
-	ir, err := NewFileReader(fn)
-	require.NoError(b, err)
-
 	b.ResetTimer()
 
 	for n := 0; n < b.N; n++ {
@@ -719,3 +611,64 @@ func TestChunksTimeOrdering(t *testing.T) {
 
 	require.NoError(t, idx.Close())
 }
+
+func TestReader_PostingsForLabelMatchingHonorsContextCancel(t *testing.T) {
+	const seriesCount = 1000
+	var input indexWriterSeriesSlice
+	for i := 1; i < seriesCount; i++ {
+		input = append(input, &indexWriterSeries{
+			labels: labels.FromStrings("__name__", fmt.Sprintf("%4d", i)),
+			chunks: []chunks.Meta{
+				{Ref: 1, MinTime: 0, MaxTime: 10},
+			},
+		})
+	}
+	ir, _, _ := createFileReader(context.Background(), t, input)
+
+	failAfter := uint64(seriesCount / 2) // Fail after processing half of the series.
+	ctx := &testutil.MockContextErrAfter{FailAfter: failAfter}
+	p := ir.PostingsForLabelMatching(ctx, "__name__", func(string) bool {
+		return true
+	})
+	require.Error(t, p.Err())
+	require.Equal(t, failAfter, ctx.Count())
+}
+
+// createFileReader creates a temporary index file. It writes the provided input to this file.
+// It returns a Reader for this file, the file's name, and the symbol map.
+func createFileReader(ctx context.Context, tb testing.TB, input indexWriterSeriesSlice) (*Reader, string, map[string]struct{}) {
+	tb.Helper()
+
+	fn := filepath.Join(tb.TempDir(), indexFilename)
+
+	iw, err := NewWriter(ctx, fn)
+	require.NoError(tb, err)
+
+	symbols := map[string]struct{}{}
+	for _, s := range input {
+		s.labels.Range(func(l labels.Label) {
+			symbols[l.Name] = struct{}{}
+			symbols[l.Value] = struct{}{}
+		})
+	}
+
+	syms := []string{}
+	for s := range symbols {
+		syms = append(syms, s)
+	}
+	slices.Sort(syms)
+	for _, s := range syms {
+		require.NoError(tb, iw.AddSymbol(s))
+	}
+	for i, s := range input {
+		require.NoError(tb, iw.AddSeries(storage.SeriesRef(i), s.labels, s.chunks...))
+	}
+	require.NoError(tb, iw.Close())
+
+	ir, err := NewFileReader(fn)
+	require.NoError(tb, err)
+	tb.Cleanup(func() {
+		require.NoError(tb, ir.Close())
+	})
+	return ir, fn, symbols
+}

tsdb/index/postings.go

@@ -416,7 +416,13 @@ func (p *MemPostings) PostingsForLabelMatching(ctx context.Context, name string,
 	}
 
 	var its []Postings
+	count := 1
 	for _, v := range vals {
+		if count%checkContextEveryNIterations == 0 && ctx.Err() != nil {
+			p.mtx.RUnlock()
+			return ErrPostings(ctx.Err())
+		}
+		count++
 		if match(v) {
 			its = append(its, NewListPostings(e[v]))
 		}

tsdb/index/postings_test.go

@@ -22,12 +22,15 @@ import (
 	"math/rand"
 	"sort"
 	"strconv"
+	"strings"
 	"testing"
 
+	"github.com/grafana/regexp"
 	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/storage"
+	"github.com/prometheus/prometheus/util/testutil"
 )
 
 func TestMemPostings_addFor(t *testing.T) {
@@ -49,7 +52,7 @@ func TestMemPostings_ensureOrder(t *testing.T) {
 		for j := range l {
 			l[j] = storage.SeriesRef(rand.Uint64())
 		}
-		v := fmt.Sprintf("%d", i)
+		v := strconv.Itoa(i)
 
 		p.m["a"][v] = l
 	}
@@ -390,7 +393,7 @@ func BenchmarkMerge(t *testing.B) {
 
 	its := make([]Postings, len(refs))
 	for _, nSeries := range []int{1, 10, 100, 1000, 10000, 100000} {
-		t.Run(fmt.Sprint(nSeries), func(bench *testing.B) {
+		t.Run(strconv.Itoa(nSeries), func(bench *testing.B) {
 			ctx := context.Background()
 			for i := 0; i < bench.N; i++ {
 				// Reset the ListPostings to their original values each time round the loop.
@@ -1282,3 +1285,71 @@ func BenchmarkListPostings(b *testing.B) {
 		})
 	}
 }
+
+func slowRegexpString() string {
+	nums := map[int]struct{}{}
+	for i := 10_000; i < 20_000; i++ {
+		if i%3 == 0 {
+			nums[i] = struct{}{}
+		}
+	}
+
+	var sb strings.Builder
+	sb.WriteString(".*(9999")
+	for i := range nums {
+		sb.WriteString("|")
+		sb.WriteString(strconv.Itoa(i))
+	}
+	sb.WriteString(").*")
+	return sb.String()
+}
+
+func BenchmarkMemPostings_PostingsForLabelMatching(b *testing.B) {
+	fast := regexp.MustCompile("^(100|200)$")
+	slowRegexp := "^" + slowRegexpString() + "$"
+	b.Logf("Slow regexp length = %d", len(slowRegexp))
+	slow := regexp.MustCompile(slowRegexp)
+
+	for _, labelValueCount := range []int{1_000, 10_000, 100_000} {
+		b.Run(fmt.Sprintf("labels=%d", labelValueCount), func(b *testing.B) {
+			mp := NewMemPostings()
+			for i := 0; i < labelValueCount; i++ {
+				mp.Add(storage.SeriesRef(i), labels.FromStrings("label", strconv.Itoa(i)))
+			}
+
+			fp, err := ExpandPostings(mp.PostingsForLabelMatching(context.Background(), "label", fast.MatchString))
+			require.NoError(b, err)
+			b.Logf("Fast matcher matches %d series", len(fp))
+			b.Run("matcher=fast", func(b *testing.B) {
+				for i := 0; i < b.N; i++ {
+					mp.PostingsForLabelMatching(context.Background(), "label", fast.MatchString).Next()
+				}
+			})
+
+			sp, err := ExpandPostings(mp.PostingsForLabelMatching(context.Background(), "label", slow.MatchString))
+			require.NoError(b, err)
+			b.Logf("Slow matcher matches %d series", len(sp))
+			b.Run("matcher=slow", func(b *testing.B) {
+				for i := 0; i < b.N; i++ {
+					mp.PostingsForLabelMatching(context.Background(), "label", slow.MatchString).Next()
+				}
+			})
+		})
+	}
+}
+
+func TestMemPostings_PostingsForLabelMatchingHonorsContextCancel(t *testing.T) {
+	memP := NewMemPostings()
+	seriesCount := 10 * checkContextEveryNIterations
+	for i := 1; i <= seriesCount; i++ {
+		memP.Add(storage.SeriesRef(i), labels.FromStrings("__name__", fmt.Sprintf("%4d", i)))
+	}
+
+	failAfter := uint64(seriesCount / 2 / checkContextEveryNIterations)
+	ctx := &testutil.MockContextErrAfter{FailAfter: failAfter}
+	p := memP.PostingsForLabelMatching(ctx, "__name__", func(string) bool {
+		return true
+	})
+	require.Error(t, p.Err())
+	require.Equal(t, failAfter+1, ctx.Count()) // Plus one for the Err() call that puts the error in the result.
+}

tsdb/querier.go

@@ -33,6 +33,9 @@ import (
 	"github.com/prometheus/prometheus/util/annotations"
 )
 
+// checkContextEveryNIterations is used in some tight loops to check if the context is done.
+const checkContextEveryNIterations = 100
+
 type blockBaseQuerier struct {
 	blockID    ulid.ULID
 	index      IndexReader
@@ -358,7 +361,12 @@ func inversePostingsForMatcher(ctx context.Context, ix IndexReader, m *labels.Ma
 	if m.Type == labels.MatchEqual && m.Value == "" {
 		res = vals
 	} else {
+		count := 1
 		for _, val := range vals {
+			if count%checkContextEveryNIterations == 0 && ctx.Err() != nil {
+				return nil, ctx.Err()
+			}
+			count++
 			if !m.Matches(val) {
 				res = append(res, val)
 			}
@@ -387,7 +395,12 @@ func labelValuesWithMatchers(ctx context.Context, r IndexReader, name string, ma
 		// re-use the allValues slice to avoid allocations
 		// this is safe because the iteration is always ahead of the append
 		filteredValues := allValues[:0]
+		count := 1
 		for _, v := range allValues {
+			if count%checkContextEveryNIterations == 0 && ctx.Err() != nil {
+				return nil, ctx.Err()
+			}
+			count++
 			if m.Matches(v) {
 				filteredValues = append(filteredValues, v)
 			}

tsdb/querier_test.go

@@ -38,6 +38,7 @@ import (
 	"github.com/prometheus/prometheus/tsdb/tombstones"
 	"github.com/prometheus/prometheus/tsdb/tsdbutil"
 	"github.com/prometheus/prometheus/util/annotations"
+	"github.com/prometheus/prometheus/util/testutil"
 )
 
 // TODO(bwplotka): Replace those mocks with remote.concreteSeriesSet.
@@ -3638,3 +3639,77 @@ func TestQueryWithOneChunkCompletelyDeleted(t *testing.T) {
 	require.NoError(t, css.Err())
 	require.Equal(t, 1, seriesCount)
 }
+
+func TestReader_PostingsForLabelMatchingHonorsContextCancel(t *testing.T) {
+	ir := mockReaderOfLabels{}
+
+	failAfter := uint64(mockReaderOfLabelsSeriesCount / 2 / checkContextEveryNIterations)
+	ctx := &testutil.MockContextErrAfter{FailAfter: failAfter}
+	_, err := labelValuesWithMatchers(ctx, ir, "__name__", labels.MustNewMatcher(labels.MatchRegexp, "__name__", ".+"))
+
+	require.Error(t, err)
+	require.Equal(t, failAfter+1, ctx.Count()) // Plus one for the Err() call that puts the error in the result.
+}
+
+func TestReader_InversePostingsForMatcherHonorsContextCancel(t *testing.T) {
+	ir := mockReaderOfLabels{}
+
+	failAfter := uint64(mockReaderOfLabelsSeriesCount / 2 / checkContextEveryNIterations)
+	ctx := &testutil.MockContextErrAfter{FailAfter: failAfter}
+	_, err := inversePostingsForMatcher(ctx, ir, labels.MustNewMatcher(labels.MatchRegexp, "__name__", ".*"))
+
+	require.Error(t, err)
+	require.Equal(t, failAfter+1, ctx.Count()) // Plus one for the Err() call that puts the error in the result.
+}
+
+type mockReaderOfLabels struct{}
+
+const mockReaderOfLabelsSeriesCount = checkContextEveryNIterations * 10
+
+func (m mockReaderOfLabels) LabelValues(context.Context, string, ...*labels.Matcher) ([]string, error) {
+	return make([]string, mockReaderOfLabelsSeriesCount), nil
+}
+
+func (m mockReaderOfLabels) LabelValueFor(context.Context, storage.SeriesRef, string) (string, error) {
+	panic("LabelValueFor called")
+}
+
+func (m mockReaderOfLabels) SortedLabelValues(context.Context, string, ...*labels.Matcher) ([]string, error) {
+	panic("SortedLabelValues called")
+}
+
+func (m mockReaderOfLabels) Close() error {
+	return nil
+}
+
+func (m mockReaderOfLabels) LabelNames(context.Context, ...*labels.Matcher) ([]string, error) {
+	panic("LabelNames called")
+}
+
+func (m mockReaderOfLabels) LabelNamesFor(context.Context, ...storage.SeriesRef) ([]string, error) {
+	panic("LabelNamesFor called")
+}
+
+func (m mockReaderOfLabels) PostingsForLabelMatching(context.Context, string, func(string) bool) index.Postings {
+	panic("PostingsForLabelMatching called")
+}
+
+func (m mockReaderOfLabels) Postings(context.Context, string, ...string) (index.Postings, error) {
+	panic("Postings called")
+}
+
+func (m mockReaderOfLabels) ShardedPostings(index.Postings, uint64, uint64) index.Postings {
+	panic("Postings called")
+}
+
+func (m mockReaderOfLabels) SortedPostings(index.Postings) index.Postings {
+	panic("SortedPostings called")
+}
+
+func (m mockReaderOfLabels) Series(storage.SeriesRef, *labels.ScratchBuilder, *[]chunks.Meta) error {
+	panic("Series called")
+}
+
+func (m mockReaderOfLabels) Symbols() index.StringIter {
+	panic("Series called")
+}

tsdb/wlog/checkpoint_test.go

@@ -19,6 +19,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -232,10 +233,10 @@ func TestCheckpoint(t *testing.T) {
 				// Write changing metadata for each series. In the end, only the latest
 				// version should end up in the checkpoint.
 				b = enc.Metadata([]record.RefMetadata{
-					{Ref: 0, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
+					{Ref: 0, Unit: strconv.FormatInt(last, 10), Help: strconv.FormatInt(last, 10)},
-					{Ref: 1, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
+					{Ref: 1, Unit: strconv.FormatInt(last, 10), Help: strconv.FormatInt(last, 10)},
-					{Ref: 2, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
+					{Ref: 2, Unit: strconv.FormatInt(last, 10), Help: strconv.FormatInt(last, 10)},
-					{Ref: 3, Unit: fmt.Sprintf("%d", last), Help: fmt.Sprintf("%d", last)},
+					{Ref: 3, Unit: strconv.FormatInt(last, 10), Help: strconv.FormatInt(last, 10)},
 				}, nil)
 				require.NoError(t, w.Log(b))
 
@@ -324,8 +325,8 @@ func TestCheckpoint(t *testing.T) {
 			testutil.RequireEqual(t, expectedRefSeries, series)
 
 			expectedRefMetadata := []record.RefMetadata{
-				{Ref: 0, Unit: fmt.Sprintf("%d", last-100), Help: fmt.Sprintf("%d", last-100)},
+				{Ref: 0, Unit: strconv.FormatInt(last-100, 10), Help: strconv.FormatInt(last-100, 10)},
-				{Ref: 2, Unit: fmt.Sprintf("%d", last-100), Help: fmt.Sprintf("%d", last-100)},
+				{Ref: 2, Unit: strconv.FormatInt(last-100, 10), Help: strconv.FormatInt(last-100, 10)},
 				{Ref: 4, Unit: "unit", Help: "help"},
 			}
 			sort.Slice(metadata, func(i, j int) bool { return metadata[i].Ref < metadata[j].Ref })

util/testutil/context.go

@@ -13,7 +13,12 @@
 
 package testutil
 
-import "time"
+import (
+	"context"
+	"time"
+
+	"go.uber.org/atomic"
+)
 
 // A MockContext provides a simple stub implementation of a Context.
 type MockContext struct {
@@ -40,3 +45,23 @@ func (c *MockContext) Err() error {
 func (c *MockContext) Value(interface{}) interface{} {
 	return nil
 }
+
+// MockContextErrAfter is a MockContext that will return an error after a certain
+// number of calls to Err().
+type MockContextErrAfter struct {
+	MockContext
+	count     atomic.Uint64
+	FailAfter uint64
+}
+
+func (c *MockContextErrAfter) Err() error {
+	c.count.Inc()
+	if c.count.Load() >= c.FailAfter {
+		return context.Canceled
+	}
+	return c.MockContext.Err()
+}
+
+func (c *MockContextErrAfter) Count() uint64 {
+	return c.count.Load()
+}

web/api/v1/api.go

@@ -116,9 +116,11 @@ type RulesRetriever interface {
 	AlertingRules() []*rules.AlertingRule
 }
 
+// StatsRenderer converts engine statistics into a format suitable for the API.
 type StatsRenderer func(context.Context, *stats.Statistics, string) stats.QueryStats
 
-func defaultStatsRenderer(_ context.Context, s *stats.Statistics, param string) stats.QueryStats {
+// DefaultStatsRenderer is the default stats renderer for the API.
+func DefaultStatsRenderer(_ context.Context, s *stats.Statistics, param string) stats.QueryStats {
 	if param != "" {
 		return stats.NewQueryStats(s)
 	}
@@ -272,7 +274,7 @@ func NewAPI(
 		buildInfo:        buildInfo,
 		gatherer:         gatherer,
 		isAgent:          isAgent,
-		statsRenderer:    defaultStatsRenderer,
+		statsRenderer:    DefaultStatsRenderer,
 
 		remoteReadHandler: remote.NewReadHandler(logger, registerer, q, configFunc, remoteReadSampleLimit, remoteReadConcurrencyLimit, remoteReadMaxBytesInFrame),
 	}
@@ -461,7 +463,7 @@ func (api *API) query(r *http.Request) (result apiFuncResult) {
 	// Optional stats field in response if parameter "stats" is not empty.
 	sr := api.statsRenderer
 	if sr == nil {
-		sr = defaultStatsRenderer
+		sr = DefaultStatsRenderer
 	}
 	qs := sr(ctx, qry.Stats(), r.FormValue("stats"))
 
@@ -563,7 +565,7 @@ func (api *API) queryRange(r *http.Request) (result apiFuncResult) {
 	// Optional stats field in response if parameter "stats" is not empty.
 	sr := api.statsRenderer
 	if sr == nil {
-		sr = defaultStatsRenderer
+		sr = DefaultStatsRenderer
 	}
 	qs := sr(ctx, qry.Stats(), r.FormValue("stats"))
 
@@ -702,7 +704,7 @@ func (api *API) labelNames(r *http.Request) apiFuncResult {
 		names = []string{}
 	}
 
-	if len(names) >= limit {
+	if len(names) > limit {
 		names = names[:limit]
 		warnings = warnings.Add(errors.New("results truncated due to limit"))
 	}
@@ -791,7 +793,7 @@ func (api *API) labelValues(r *http.Request) (result apiFuncResult) {
 
 	slices.Sort(vals)
 
-	if len(vals) >= limit {
+	if len(vals) > limit {
 		vals = vals[:limit]
 		warnings = warnings.Add(errors.New("results truncated due to limit"))
 	}
@@ -887,7 +889,8 @@ func (api *API) series(r *http.Request) (result apiFuncResult) {
 		}
 		metrics = append(metrics, set.At().Labels())
 
-		if len(metrics) >= limit {
+		if len(metrics) > limit {
+			metrics = metrics[:limit]
 			warnings.Add(errors.New("results truncated due to limit"))
 			return apiFuncResult{metrics, nil, warnings, closer}
 		}

web/api/v1/api_test.go

@@ -25,6 +25,7 @@ import (
 	"reflect"
 	"runtime"
 	"sort"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -1059,6 +1060,7 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 		responseLen           int // If nonzero, check only the length; `response` is ignored.
 		responseMetadataTotal int
 		responseAsJSON        string
+		warningsCount         int
 		errType               errorType
 		sorter                func(interface{})
 		metadata              []targetMetadata
@@ -1416,7 +1418,17 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 				"match[]": []string{"test_metric1"},
 				"limit":   []string{"1"},
 			},
-			responseLen: 1, // API does not specify which particular value will come back.
+			responseLen:   1, // API does not specify which particular value will come back.
+			warningsCount: 1,
+		},
+		{
+			endpoint: api.series,
+			query: url.Values{
+				"match[]": []string{"test_metric1"},
+				"limit":   []string{"2"},
+			},
+			responseLen:   2, // API does not specify which particular value will come back.
+			warningsCount: 0, // No warnings if limit isn't exceeded.
 		},
 		// Missing match[] query params in series requests.
 		{
@@ -2699,7 +2711,19 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 				query: url.Values{
 					"limit": []string{"2"},
 				},
-				responseLen: 2, // API does not specify which particular values will come back.
+				responseLen:   2, // API does not specify which particular values will come back.
+				warningsCount: 1,
+			},
+			{
+				endpoint: api.labelValues,
+				params: map[string]string{
+					"name": "__name__",
+				},
+				query: url.Values{
+					"limit": []string{"4"},
+				},
+				responseLen:   4, // API does not specify which particular values will come back.
+				warningsCount: 0, // No warnings if limit isn't exceeded.
 			},
 			// Label names.
 			{
@@ -2846,7 +2870,16 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 				query: url.Values{
 					"limit": []string{"2"},
 				},
-				responseLen: 2, // API does not specify which particular values will come back.
+				responseLen:   2, // API does not specify which particular values will come back.
+				warningsCount: 1,
+			},
+			{
+				endpoint: api.labelNames,
+				query: url.Values{
+					"limit": []string{"3"},
+				},
+				responseLen:   3, // API does not specify which particular values will come back.
+				warningsCount: 0, // No warnings if limit isn't exceeded.
 			},
 		}...)
 	}
@@ -2923,6 +2956,8 @@ func testEndpoints(t *testing.T, api *API, tr *testTargetRetriever, es storage.E
 						require.NoError(t, err)
 						require.JSONEq(t, test.responseAsJSON, string(s))
 					}
+
+					require.Len(t, res.warnings, test.warningsCount)
 				})
 			}
 		})
@@ -3544,7 +3579,7 @@ func TestTSDBStatus(t *testing.T) {
 		},
 	} {
 		tc := tc
-		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
 			api := &API{db: tc.db, gatherer: prometheus.DefaultGatherer}
 			endpoint := tc.endpoint(api)
 			req, err := http.NewRequest(tc.method, fmt.Sprintf("?%s", tc.values.Encode()), nil)

web/federate_test.go

@@ -22,6 +22,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"sort"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -341,8 +342,8 @@ func TestFederationWithNativeHistograms(t *testing.T) {
 	}
 	app := db.Appender(context.Background())
 	for i := 0; i < 6; i++ {
-		l := labels.FromStrings("__name__", "test_metric", "foo", fmt.Sprintf("%d", i))
+		l := labels.FromStrings("__name__", "test_metric", "foo", strconv.Itoa(i))
-		expL := labels.FromStrings("__name__", "test_metric", "instance", "", "foo", fmt.Sprintf("%d", i))
+		expL := labels.FromStrings("__name__", "test_metric", "instance", "", "foo", strconv.Itoa(i))
 		var err error
 		switch i {
 		case 0, 3: