From 252031c86f5c6fe7acad504bc6f3162175f347b2 Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Sat, 30 Dec 2023 19:13:59 +0000
Subject: [PATCH 1/4] Revert "Adding small test update for temp dir using
 t.TempDir (#13293)"

This reverts commit 2ddb3596ef4d2b1de482337ce1943476699b82fb.

Various tests are failing in CI after this change; reverting to free up
other work.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 promql/engine_test.go                |  5 ++++-
 tsdb/tsdbutil/dir_locker_testutil.go | 10 +++++++---
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/promql/engine_test.go b/promql/engine_test.go
index b3e7d40948..105cdc10d5 100644
--- a/promql/engine_test.go
+++ b/promql/engine_test.go
@@ -18,6 +18,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"os"
 	"sort"
 	"testing"
 	"time"
@@ -46,7 +47,9 @@ func TestMain(m *testing.M) {
 func TestQueryConcurrency(t *testing.T) {
 	maxConcurrency := 10
 
-	dir := t.TempDir()
+	dir, err := os.MkdirTemp("", "test_concurrency")
+	require.NoError(t, err)
+	defer os.RemoveAll(dir)
 	queryTracker := NewActiveQueryTracker(dir, maxConcurrency, nil)
 	t.Cleanup(queryTracker.Close)
 
diff --git a/tsdb/tsdbutil/dir_locker_testutil.go b/tsdb/tsdbutil/dir_locker_testutil.go
index a7f43d8eee..a4cf5abd68 100644
--- a/tsdb/tsdbutil/dir_locker_testutil.go
+++ b/tsdb/tsdbutil/dir_locker_testutil.go
@@ -60,8 +60,12 @@ func TestDirLockerUsage(t *testing.T, open func(t *testing.T, data string, creat
 
 	for _, c := range cases {
 		t.Run(fmt.Sprintf("%+v", c), func(t *testing.T) {
-			tmpdir := t.TempDir()
-			
+			tmpdir, err := os.MkdirTemp("", "test")
+			require.NoError(t, err)
+			t.Cleanup(func() {
+				require.NoError(t, os.RemoveAll(tmpdir))
+			})
+
 			// Test preconditions (file already exists + lockfile option)
 			if c.fileAlreadyExists {
 				tmpLocker, err := NewDirLocker(tmpdir, "tsdb", log.NewNopLogger(), nil)
@@ -78,7 +82,7 @@ func TestDirLockerUsage(t *testing.T, open func(t *testing.T, data string, creat
 
 			// Check that the lockfile is always deleted
 			if !c.lockFileDisabled {
-				_, err := os.Stat(locker.path)
+				_, err = os.Stat(locker.path)
 				require.True(t, os.IsNotExist(err), "lockfile was not deleted")
 			}
 		})

From e64d7d8928323d3ec95c5bfccb66b30a6bd5393e Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Thu, 7 Dec 2023 15:27:59 +0000
Subject: [PATCH 2/4] agent: make the global hash lookup table smaller

This is the same change made in #13040, plus subsequent improvements,
applied to agent-mode code.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 tsdb/agent/series.go      | 130 +++++++++++++++++++++++++-------------
 tsdb/agent/series_test.go |  60 ++++++++++++++++++
 2 files changed, 146 insertions(+), 44 deletions(-)

diff --git a/tsdb/agent/series.go b/tsdb/agent/series.go
index d38518f71e..76e7342171 100644
--- a/tsdb/agent/series.go
+++ b/tsdb/agent/series.go
@@ -45,14 +45,23 @@ func (m *memSeries) updateTimestamp(newTs int64) bool {
 	return false
 }
 
-// seriesHashmap is a simple hashmap for memSeries by their label set.
-// It is built on top of a regular hashmap and holds a slice of series to
-// resolve hash collisions. Its methods require the hash to be submitted
+// seriesHashmap lets agent find a memSeries by its label set, via a 64-bit hash.
+// There is one map for the common case where the hash value is unique, and a
+// second map for the case that two series have the same hash value.
+// Each series is in only one of the maps. Its methods require the hash to be submitted
 // with the label set to avoid re-computing hash throughout the code.
-type seriesHashmap map[uint64][]*memSeries
+type seriesHashmap struct {
+	unique    map[uint64]*memSeries
+	conflicts map[uint64][]*memSeries
+}
 
-func (m seriesHashmap) Get(hash uint64, lset labels.Labels) *memSeries {
-	for _, s := range m[hash] {
+func (m *seriesHashmap) Get(hash uint64, lset labels.Labels) *memSeries {
+	if s, found := m.unique[hash]; found {
+		if labels.Equal(s.lset, lset) {
+			return s
+		}
+	}
+	for _, s := range m.conflicts[hash] {
 		if labels.Equal(s.lset, lset) {
 			return s
 		}
@@ -60,28 +69,49 @@ func (m seriesHashmap) Get(hash uint64, lset labels.Labels) *memSeries {
 	return nil
 }
 
-func (m seriesHashmap) Set(hash uint64, s *memSeries) {
-	seriesSet := m[hash]
+func (m *seriesHashmap) Set(hash uint64, s *memSeries) {
+	if existing, found := m.unique[hash]; !found || labels.Equal(existing.lset, s.lset) {
+		m.unique[hash] = s
+		return
+	}
+	if m.conflicts == nil {
+		m.conflicts = make(map[uint64][]*memSeries)
+	}
+	seriesSet := m.conflicts[hash]
 	for i, prev := range seriesSet {
 		if labels.Equal(prev.lset, s.lset) {
 			seriesSet[i] = s
 			return
 		}
 	}
-	m[hash] = append(seriesSet, s)
+	m.conflicts[hash] = append(seriesSet, s)
 }
 
-func (m seriesHashmap) Delete(hash uint64, ref chunks.HeadSeriesRef) {
+func (m *seriesHashmap) Delete(hash uint64, ref chunks.HeadSeriesRef) {
 	var rem []*memSeries
-	for _, s := range m[hash] {
-		if s.ref != ref {
-			rem = append(rem, s)
+	unique, found := m.unique[hash]
+	switch {
+	case !found: // Supplied hash is not stored.
+		return
+	case unique.ref == ref:
+		conflicts := m.conflicts[hash]
+		if len(conflicts) == 0 { // Exactly one series with this hash was stored
+			delete(m.unique, hash)
+			return
+		}
+		m.unique[hash] = conflicts[0] // First remaining series goes in 'unique'.
+		rem = conflicts[1:]           // Keep the rest.
+	default: // The series to delete is somewhere in 'conflicts'. Keep all the ones that don't match.
+		for _, s := range m.conflicts[hash] {
+			if s.ref != ref {
+				rem = append(rem, s)
+			}
 		}
 	}
 	if len(rem) == 0 {
-		delete(m, hash)
+		delete(m.conflicts, hash)
 	} else {
-		m[hash] = rem
+		m.conflicts[hash] = rem
 	}
 }
 
@@ -117,7 +147,10 @@ func newStripeSeries(stripeSize int) *stripeSeries {
 		s.series[i] = map[chunks.HeadSeriesRef]*memSeries{}
 	}
 	for i := range s.hashes {
-		s.hashes[i] = seriesHashmap{}
+		s.hashes[i] = seriesHashmap{
+			unique:    map[uint64]*memSeries{},
+			conflicts: nil, // Initialized on demand in set().
+		}
 	}
 	for i := range s.exemplars {
 		s.exemplars[i] = map[chunks.HeadSeriesRef]*exemplar.Exemplar{}
@@ -136,40 +169,49 @@ func (s *stripeSeries) GC(mint int64) map[chunks.HeadSeriesRef]struct{} {
 	defer s.gcMut.Unlock()
 
 	deleted := map[chunks.HeadSeriesRef]struct{}{}
+
+	// For one series, truncate old chunks and check if any chunks left. If not, mark as deleted and collect the ID.
+	check := func(hashLock int, hash uint64, series *memSeries) {
+		series.Lock()
+
+		// Any series that has received a write since mint is still alive.
+		if series.lastTs >= mint {
+			series.Unlock()
+			return
+		}
+
+		// The series is stale. We need to obtain a second lock for the
+		// ref if it's different than the hash lock.
+		refLock := int(series.ref) & (s.size - 1)
+		if hashLock != refLock {
+			s.locks[refLock].Lock()
+		}
+
+		deleted[series.ref] = struct{}{}
+		delete(s.series[refLock], series.ref)
+		s.hashes[hashLock].Delete(hash, series.ref)
+
+		// Since the series is gone, we'll also delete
+		// the latest stored exemplar.
+		delete(s.exemplars[refLock], series.ref)
+
+		if hashLock != refLock {
+			s.locks[refLock].Unlock()
+		}
+		series.Unlock()
+	}
+
 	for hashLock := 0; hashLock < s.size; hashLock++ {
 		s.locks[hashLock].Lock()
 
-		for hash, all := range s.hashes[hashLock] {
+		for hash, all := range s.hashes[hashLock].conflicts {
 			for _, series := range all {
-				series.Lock()
-
-				// Any series that has received a write since mint is still alive.
-				if series.lastTs >= mint {
-					series.Unlock()
-					continue
-				}
-
-				// The series is stale. We need to obtain a second lock for the
-				// ref if it's different than the hash lock.
-				refLock := int(series.ref) & (s.size - 1)
-				if hashLock != refLock {
-					s.locks[refLock].Lock()
-				}
-
-				deleted[series.ref] = struct{}{}
-				delete(s.series[refLock], series.ref)
-				s.hashes[hashLock].Delete(hash, series.ref)
-
-				// Since the series is gone, we'll also delete
-				// the latest stored exemplar.
-				delete(s.exemplars[refLock], series.ref)
-
-				if hashLock != refLock {
-					s.locks[refLock].Unlock()
-				}
-				series.Unlock()
+				check(hashLock, hash, series)
 			}
 		}
+		for hash, series := range s.hashes[hashLock].unique {
+			check(hashLock, hash, series)
+		}
 
 		s.locks[hashLock].Unlock()
 	}
diff --git a/tsdb/agent/series_test.go b/tsdb/agent/series_test.go
index 480f6c0263..ae327d8582 100644
--- a/tsdb/agent/series_test.go
+++ b/tsdb/agent/series_test.go
@@ -74,3 +74,63 @@ func TestNoDeadlock(t *testing.T) {
 		require.FailNow(t, "deadlock detected")
 	}
 }
+
+func labelsWithHashCollision() (labels.Labels, labels.Labels) {
+	// These two series have the same XXHash; thanks to https://github.com/pstibrany/labels_hash_collisions
+	ls1 := labels.FromStrings("__name__", "metric", "lbl1", "value", "lbl2", "l6CQ5y")
+	ls2 := labels.FromStrings("__name__", "metric", "lbl1", "value", "lbl2", "v7uDlF")
+
+	if ls1.Hash() != ls2.Hash() {
+		// These ones are the same when using -tags stringlabels
+		ls1 = labels.FromStrings("__name__", "metric", "lbl", "HFnEaGl")
+		ls2 = labels.FromStrings("__name__", "metric", "lbl", "RqcXatm")
+	}
+
+	if ls1.Hash() != ls2.Hash() {
+		panic("This code needs to be updated: find new labels with colliding hash values.")
+	}
+
+	return ls1, ls2
+}
+
+// stripeSeriesWithCollidingSeries returns a stripeSeries with two memSeries having the same, colliding, hash.
+func stripeSeriesWithCollidingSeries(_ *testing.T) (*stripeSeries, *memSeries, *memSeries) {
+	lbls1, lbls2 := labelsWithHashCollision()
+	ms1 := memSeries{
+		lset: lbls1,
+	}
+	ms2 := memSeries{
+		lset: lbls2,
+	}
+	hash := lbls1.Hash()
+	s := newStripeSeries(1)
+
+	s.Set(hash, &ms1)
+	s.Set(hash, &ms2)
+
+	return s, &ms1, &ms2
+}
+
+func TestStripeSeries_Get(t *testing.T) {
+	s, ms1, ms2 := stripeSeriesWithCollidingSeries(t)
+	hash := ms1.lset.Hash()
+
+	// Verify that we can get both of the series despite the hash collision
+	got := s.GetByHash(hash, ms1.lset)
+	require.Same(t, ms1, got)
+	got = s.GetByHash(hash, ms2.lset)
+	require.Same(t, ms2, got)
+}
+
+func TestStripeSeries_gc(t *testing.T) {
+	s, ms1, ms2 := stripeSeriesWithCollidingSeries(t)
+	hash := ms1.lset.Hash()
+
+	s.GC(1)
+
+	// Verify that we can get neither ms1 nor ms2 after gc-ing corresponding series
+	got := s.GetByHash(hash, ms1.lset)
+	require.Nil(t, got)
+	got = s.GetByHash(hash, ms2.lset)
+	require.Nil(t, got)
+}

From bad3f23f23817881d8d91f3705b8c7d31ccecfe9 Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Sat, 30 Dec 2023 14:07:09 +0000
Subject: [PATCH 3/4] agent: add BenchmarkCreateSeries

Based on the one in tsdb/head_test.go.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 tsdb/agent/db_test.go | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/tsdb/agent/db_test.go b/tsdb/agent/db_test.go
index 1e0976c3f1..32b7e4394e 100644
--- a/tsdb/agent/db_test.go
+++ b/tsdb/agent/db_test.go
@@ -84,7 +84,7 @@ func TestDB_InvalidSeries(t *testing.T) {
 	})
 }
 
-func createTestAgentDB(t *testing.T, reg prometheus.Registerer, opts *Options) *DB {
+func createTestAgentDB(t testing.TB, reg prometheus.Registerer, opts *Options) *DB {
 	t.Helper()
 
 	dbDir := t.TempDir()
@@ -878,3 +878,21 @@ func TestDBAllowOOOSamples(t *testing.T) {
 	require.Equal(t, float64(80), m.Metric[1].Counter.GetValue(), "agent wal mismatch of total appended histograms")
 	require.NoError(t, db.Close())
 }
+
+func BenchmarkCreateSeries(b *testing.B) {
+	s := createTestAgentDB(b, nil, DefaultOptions())
+	defer s.Close()
+
+	app := s.Appender(context.Background()).(*appender)
+	lbls := make([]labels.Labels, b.N)
+
+	for i, l := range labelsForTest("benchmark", b.N) {
+		lbls[i] = labels.New(l...)
+	}
+
+	b.ResetTimer()
+
+	for _, l := range lbls {
+		app.getOrCreate(l)
+	}
+}

From 6ae6207a7ff6b19613de311e05e1463f6fda0608 Mon Sep 17 00:00:00 2001
From: Callum Styan <callumstyan@gmail.com>
Date: Wed, 3 Jan 2024 16:37:34 -0800
Subject: [PATCH 4/4] change enum names to fit buf build recommend enum naming
 and lint rules

Signed-off-by: Callum Styan <callumstyan@gmail.com>
---
 prompb/write/v2/types.pb.go | 185 ++++++++++++++++++------------------
 prompb/write/v2/types.proto |  24 ++---
 2 files changed, 106 insertions(+), 103 deletions(-)

diff --git a/prompb/write/v2/types.pb.go b/prompb/write/v2/types.pb.go
index 8ebd561fd0..1edb6a748e 100644
--- a/prompb/write/v2/types.pb.go
+++ b/prompb/write/v2/types.pb.go
@@ -27,36 +27,36 @@ const _ = proto.GoGoProtoPackageIsVersion3 // please upgrade the proto package
 type Metadata_MetricType int32
 
 const (
-	Metadata_UNKNOWN        Metadata_MetricType = 0
-	Metadata_COUNTER        Metadata_MetricType = 1
-	Metadata_GAUGE          Metadata_MetricType = 2
-	Metadata_HISTOGRAM      Metadata_MetricType = 3
-	Metadata_GAUGEHISTOGRAM Metadata_MetricType = 4
-	Metadata_SUMMARY        Metadata_MetricType = 5
-	Metadata_INFO           Metadata_MetricType = 6
-	Metadata_STATESET       Metadata_MetricType = 7
+	Metadata_METRIC_TYPE_UNSPECIFIED    Metadata_MetricType = 0
+	Metadata_METRIC_TYPE_COUNTER        Metadata_MetricType = 1
+	Metadata_METRIC_TYPE_GAUGE          Metadata_MetricType = 2
+	Metadata_METRIC_TYPE_HISTOGRAM      Metadata_MetricType = 3
+	Metadata_METRIC_TYPE_GAUGEHISTOGRAM Metadata_MetricType = 4
+	Metadata_METRIC_TYPE_SUMMARY        Metadata_MetricType = 5
+	Metadata_METRIC_TYPE_INFO           Metadata_MetricType = 6
+	Metadata_METRIC_TYPE_STATESET       Metadata_MetricType = 7
 )
 
 var Metadata_MetricType_name = map[int32]string{
-	0: "UNKNOWN",
-	1: "COUNTER",
-	2: "GAUGE",
-	3: "HISTOGRAM",
-	4: "GAUGEHISTOGRAM",
-	5: "SUMMARY",
-	6: "INFO",
-	7: "STATESET",
+	0: "METRIC_TYPE_UNSPECIFIED",
+	1: "METRIC_TYPE_COUNTER",
+	2: "METRIC_TYPE_GAUGE",
+	3: "METRIC_TYPE_HISTOGRAM",
+	4: "METRIC_TYPE_GAUGEHISTOGRAM",
+	5: "METRIC_TYPE_SUMMARY",
+	6: "METRIC_TYPE_INFO",
+	7: "METRIC_TYPE_STATESET",
 }
 
 var Metadata_MetricType_value = map[string]int32{
-	"UNKNOWN":        0,
-	"COUNTER":        1,
-	"GAUGE":          2,
-	"HISTOGRAM":      3,
-	"GAUGEHISTOGRAM": 4,
-	"SUMMARY":        5,
-	"INFO":           6,
-	"STATESET":       7,
+	"METRIC_TYPE_UNSPECIFIED":    0,
+	"METRIC_TYPE_COUNTER":        1,
+	"METRIC_TYPE_GAUGE":          2,
+	"METRIC_TYPE_HISTOGRAM":      3,
+	"METRIC_TYPE_GAUGEHISTOGRAM": 4,
+	"METRIC_TYPE_SUMMARY":        5,
+	"METRIC_TYPE_INFO":           6,
+	"METRIC_TYPE_STATESET":       7,
 }
 
 func (x Metadata_MetricType) String() string {
@@ -70,24 +70,24 @@ func (Metadata_MetricType) EnumDescriptor() ([]byte, []int) {
 type Histogram_ResetHint int32
 
 const (
-	Histogram_UNKNOWN Histogram_ResetHint = 0
-	Histogram_YES     Histogram_ResetHint = 1
-	Histogram_NO      Histogram_ResetHint = 2
-	Histogram_GAUGE   Histogram_ResetHint = 3
+	Histogram_RESET_HINT_UNSPECIFIED Histogram_ResetHint = 0
+	Histogram_RESET_HINT_YES         Histogram_ResetHint = 1
+	Histogram_RESET_HINT_NO          Histogram_ResetHint = 2
+	Histogram_RESET_HINT_GAUGE       Histogram_ResetHint = 3
 )
 
 var Histogram_ResetHint_name = map[int32]string{
-	0: "UNKNOWN",
-	1: "YES",
-	2: "NO",
-	3: "GAUGE",
+	0: "RESET_HINT_UNSPECIFIED",
+	1: "RESET_HINT_YES",
+	2: "RESET_HINT_NO",
+	3: "RESET_HINT_GAUGE",
 }
 
 var Histogram_ResetHint_value = map[string]int32{
-	"UNKNOWN": 0,
-	"YES":     1,
-	"NO":      2,
-	"GAUGE":   3,
+	"RESET_HINT_UNSPECIFIED": 0,
+	"RESET_HINT_YES":         1,
+	"RESET_HINT_NO":          2,
+	"RESET_HINT_GAUGE":       3,
 }
 
 func (x Histogram_ResetHint) String() string {
@@ -416,7 +416,7 @@ func (m *Metadata) GetType() Metadata_MetricType {
 	if m != nil {
 		return m.Type
 	}
-	return Metadata_UNKNOWN
+	return Metadata_METRIC_TYPE_UNSPECIFIED
 }
 
 func (m *Metadata) GetHelpRef() uint32 {
@@ -653,7 +653,7 @@ func (m *Histogram) GetResetHint() Histogram_ResetHint {
 	if m != nil {
 		return m.ResetHint
 	}
-	return Histogram_UNKNOWN
+	return Histogram_RESET_HINT_UNSPECIFIED
 }
 
 func (m *Histogram) GetTimestamp() int64 {
@@ -748,59 +748,62 @@ func init() {
 func init() { proto.RegisterFile("write/v2/types.proto", fileDescriptor_4919b8b88a093366) }
 
 var fileDescriptor_4919b8b88a093366 = []byte{
-	// 831 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x84, 0x55, 0xdd, 0x6e, 0xe3, 0x44,
-	0x14, 0xee, 0xc4, 0x49, 0x6c, 0x9f, 0xfc, 0xac, 0x3b, 0x14, 0x64, 0x10, 0xdb, 0x0d, 0x91, 0x80,
-	0x08, 0xa4, 0x14, 0xc2, 0x0a, 0x09, 0xd4, 0x9b, 0x64, 0xc9, 0x36, 0x15, 0x6a, 0x22, 0x8d, 0x5d,
-	0xad, 0x96, 0x9b, 0x68, 0x9a, 0x4c, 0x12, 0x0b, 0xff, 0xe1, 0x99, 0x04, 0xca, 0x7b, 0xf1, 0x08,
-	0x48, 0x7b, 0xc9, 0x13, 0x20, 0xd4, 0x07, 0xe0, 0x19, 0xd0, 0x8c, 0x7f, 0xa6, 0x2d, 0x5a, 0xed,
-	0xdd, 0x9c, 0xef, 0x7c, 0xdf, 0x9c, 0xef, 0x1c, 0x9f, 0x91, 0xe1, 0xe4, 0xd7, 0x2c, 0x10, 0xec,
-	0xec, 0x30, 0x3a, 0x13, 0xb7, 0x29, 0xe3, 0xc3, 0x34, 0x4b, 0x44, 0x82, 0x2d, 0x85, 0x0e, 0x0f,
-	0xa3, 0x8f, 0x4e, 0xb6, 0xc9, 0x36, 0x51, 0xe0, 0x99, 0x3c, 0xe5, 0xf9, 0xfe, 0x1a, 0xda, 0xaf,
-	0x24, 0x83, 0xb0, 0x5f, 0xf6, 0x8c, 0x0b, 0xec, 0x82, 0xc9, 0x6f, 0xa3, 0x9b, 0x24, 0xe4, 0x2e,
-	0xea, 0x19, 0x03, 0x9b, 0x94, 0x21, 0xfe, 0x1e, 0x40, 0x04, 0x11, 0xe3, 0x2c, 0x0b, 0x18, 0x77,
-	0x6b, 0x3d, 0x63, 0xd0, 0x1a, 0x9d, 0x0c, 0xcb, 0xeb, 0x87, 0x7e, 0x10, 0x31, 0x4f, 0xe5, 0x26,
-	0xf5, 0x37, 0x7f, 0x3f, 0x3b, 0x22, 0xf7, 0xd8, 0xfd, 0x3f, 0x6a, 0x00, 0x9a, 0x80, 0x9f, 0x41,
-	0x2b, 0xa4, 0x37, 0x2c, 0xe4, 0xcb, 0x8c, 0x6d, 0xf2, 0x42, 0x1d, 0x02, 0x39, 0x44, 0xd8, 0x86,
-	0xe3, 0xaf, 0xc0, 0xe4, 0x34, 0x4a, 0xc3, 0xaa, 0x90, 0xa3, 0x0b, 0x79, 0x2a, 0x51, 0x14, 0x29,
-	0x69, 0xf8, 0x5b, 0xb0, 0xd9, 0x6f, 0x2c, 0x4a, 0x43, 0x9a, 0x71, 0xd7, 0x50, 0x1a, 0xac, 0x35,
-	0xd3, 0x22, 0x55, 0xa8, 0x34, 0x15, 0x7f, 0x07, 0xb0, 0x0b, 0xb8, 0x48, 0xb6, 0x19, 0x8d, 0xb8,
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+	// 875 bytes of a gzipped FileDescriptorProto
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+	0x00, 0xff, 0xff, 0x68, 0x88, 0x14, 0xcb, 0x1e, 0x07, 0x00, 0x00,
 }
 
 func (m *WriteRequest) Marshal() (dAtA []byte, err error) {
diff --git a/prompb/write/v2/types.proto b/prompb/write/v2/types.proto
index c225aa9acf..ad225025e2 100644
--- a/prompb/write/v2/types.proto
+++ b/prompb/write/v2/types.proto
@@ -61,14 +61,14 @@ message Sample {
 
 message Metadata {
   enum MetricType {
-    UNKNOWN        = 0;
-    COUNTER        = 1;
-    GAUGE          = 2;
-    HISTOGRAM      = 3;
-    GAUGEHISTOGRAM = 4;
-    SUMMARY        = 5;
-    INFO           = 6;
-    STATESET       = 7;
+    METRIC_TYPE_UNSPECIFIED        = 0;
+    METRIC_TYPE_COUNTER        = 1;
+    METRIC_TYPE_GAUGE          = 2;
+    METRIC_TYPE_HISTOGRAM      = 3;
+    METRIC_TYPE_GAUGEHISTOGRAM = 4;
+    METRIC_TYPE_SUMMARY        = 5;
+    METRIC_TYPE_INFO           = 6;
+    METRIC_TYPE_STATESET       = 7;
   }
   MetricType type = 1;
   uint32 help_ref = 3;
@@ -83,10 +83,10 @@ message Metadata {
 // integer histogram as well as a float histogram.
 message Histogram {
   enum ResetHint {
-    UNKNOWN = 0; // Need to test for a counter reset explicitly.
-    YES     = 1; // This is the 1st histogram after a counter reset.
-    NO      = 2; // There was no counter reset between this and the previous Histogram.
-    GAUGE   = 3; // This is a gauge histogram where counter resets don't happen.
+    RESET_HINT_UNSPECIFIED = 0; // Need to test for a counter reset explicitly.
+    RESET_HINT_YES     = 1; // This is the 1st histogram after a counter reset.
+    RESET_HINT_NO      = 2; // There was no counter reset between this and the previous Histogram.
+    RESET_HINT_GAUGE   = 3; // This is a gauge histogram where counter resets don't happen.
   }
 
   oneof count { // Count of observations in the histogram.