Attempt for record type

tsdb/agent/db.go

@@ -463,7 +463,7 @@ func (db *DB) loadWAL(r *wlog.Reader, multiRef map[chunks.HeadSeriesRef]chunks.H
 					return
 				}
 				decoded <- samples
-			case record.HistogramSamples:
+			case record.HistogramSamples, record.CustomBucketHistogramSamples:
 				histograms := histogramsPool.Get()[:0]
 				histograms, err = dec.HistogramSamples(rec, histograms)
 				if err != nil {
@@ -475,7 +475,7 @@ func (db *DB) loadWAL(r *wlog.Reader, multiRef map[chunks.HeadSeriesRef]chunks.H
 					return
 				}
 				decoded <- histograms
-			case record.FloatHistogramSamples:
+			case record.FloatHistogramSamples, record.CustomBucketFloatHistogramSamples:
 				floatHistograms := floatHistogramsPool.Get()[:0]
 				floatHistograms, err = dec.FloatHistogramSamples(rec, floatHistograms)
 				if err != nil {
@@ -1154,19 +1154,40 @@ func (a *appender) log() error {
 	}
 
 	if len(a.pendingHistograms) > 0 {
-		buf = encoder.HistogramSamples(a.pendingHistograms, buf)
+		buf1, buf2 := encoder.HistogramSamples(a.pendingHistograms, buf)
-		if err := a.wal.Log(buf); err != nil {
+		//buf = append(buf1, buf2...)
+		//if err := a.wal.Log(buf); err != nil {
+		//	return err
+		//}
+		if len(buf1) > 0 {
+			buf = buf1[:0]
+			if err := a.wal.Log(buf1); err != nil {
 				return err
 			}
-		buf = buf[:0]
+		}
+		if len(buf2) > 0 {
+			buf = buf2[:0]
+			if err := a.wal.Log(buf2); err != nil {
+				return err
+			}
+		}
 	}
 
 	if len(a.pendingFloatHistograms) > 0 {
-		buf = encoder.FloatHistogramSamples(a.pendingFloatHistograms, buf)
+		buf1, buf2 := encoder.FloatHistogramSamples(a.pendingFloatHistograms, buf)
-		if err := a.wal.Log(buf); err != nil {
+		if len(buf1) > 0 {
+			buf = buf1[:0]
+			if err := a.wal.Log(buf1); err != nil {
 				return err
 			}
-		buf = buf[:0]
+		}
+		if len(buf2) > 0 {
+			buf = buf2[:0]
+			if err := a.wal.Log(buf2); err != nil {
+				return err
+			}
+		}
+		//buf = buf[:0]
 	}
 
 	if len(a.pendingExamplars) > 0 {

tsdb/agent/db_test.go

@@ -193,7 +193,8 @@ func TestCommit(t *testing.T) {
 	)
 	for r.Next() {
 		rec := r.Record()
-		switch dec.Type(rec) {
+		recType := dec.Type(rec)
+		switch recType {
 		case record.Series:
 			var series []record.RefSeries
 			series, err = dec.Series(rec, series)
@@ -206,13 +207,13 @@ func TestCommit(t *testing.T) {
 			require.NoError(t, err)
 			walSamplesCount += len(samples)
 
-		case record.HistogramSamples:
+		case record.HistogramSamples, record.CustomBucketHistogramSamples:
 			var histograms []record.RefHistogramSample
 			histograms, err = dec.HistogramSamples(rec, histograms)
 			require.NoError(t, err)
 			walHistogramCount += len(histograms)
 
-		case record.FloatHistogramSamples:
+		case record.FloatHistogramSamples, record.CustomBucketFloatHistogramSamples:
 			var floatHistograms []record.RefFloatHistogramSample
 			floatHistograms, err = dec.FloatHistogramSamples(rec, floatHistograms)
 			require.NoError(t, err)

tsdb/docs/format/wal.md

@@ -79,6 +79,32 @@ The first sample record begins at the second row.
 └──────────────────────────────────────────────────────────────────┘
 ```
 
+### Native histogram records
+
+Native histogram records are encoded as 
+
+```
+┌──────────────────────────────────────────────────────────────────┐
+│ type = 2 <1b>                                                    │
+├──────────────────────────────────────────────────────────────────┤
+│ ┌────────────────────┬───────────────────────────┐               │
+│ │ id <8b>            │ timestamp <8b>            │               │
+│ └────────────────────┴───────────────────────────┘               │
+│ ┌────────────────────┬───────────────────────────┬               │
+│ │ id_delta <uvarint> │ timestamp_delta <uvarint> │               │
+│ ├────────────────────┴───────────────────────────┴─────────────┤ │
+│ │  n = len(labels) <uvarint>                                   │ │
+│ ├──────────────────────┬───────────────────────────────────────┤ │
+│ │ len(str_1) <uvarint> │ str_1 <bytes>                         │ │
+│ ├──────────────────────┴───────────────────────────────────────┤ │
+│ │  ...                                                         │ │
+│ ├───────────────────────┬──────────────────────────────────────┤ │
+│ │ len(str_2n) <uvarint> │ str_2n <bytes> │                     │ │
+│ └───────────────────────┴────────────────┴─────────────────────┘ │
+│                              . . .                               │
+└──────────────────────────────────────────────────────────────────┘
+```
+
 ### Tombstone records
 
 Tombstone records encode tombstones as a list of triples `(series_id, min_time, max_time)`

tsdb/encoding/encoding.go

@@ -104,14 +104,6 @@ func (e *Encbuf) PutHashSum(h hash.Hash) {
 	e.B = h.Sum(e.B)
 }
 
-// IsWholeWhenMultiplied checks to see if the number when multiplied by 1000 can
-// be converted into an integer without losing precision.
-func IsWholeWhenMultiplied(in float64) bool {
-	i := uint(math.Round(in * 1000))
-	out := float64(i) / 1000
-	return in == out
-}
-
 // Decbuf provides safe methods to extract data from a byte slice. It does all
 // necessary bounds checking and advancing of the byte slice.
 // Several datums can be extracted without checking for errors. However, before using

tsdb/head_append.go

@@ -942,19 +942,49 @@ func (a *headAppender) log() error {
 		}
 	}
 	if len(a.histograms) > 0 {
-		rec = enc.HistogramSamples(a.histograms, buf)
+		rec1, rec2 := enc.HistogramSamples(a.histograms, buf)
-		buf = rec[:0]
+		//rec = append(rec1, rec2...)
-		if err := a.head.wal.Log(rec); err != nil {
+		//
+		//buf = rec[:0]
+		//
+		//if err := a.head.wal.Log(rec); err != nil {
+		//	return fmt.Errorf("log samples: %w", err)
+		//}
+		if len(rec1) != 0 {
+			buf = rec1[:0]
+			if err := a.head.wal.Log(rec1); err != nil {
 				return fmt.Errorf("log histograms: %w", err)
 			}
 		}
+		if len(rec2) != 0 {
+			buf = rec2[:0]
+			if err := a.head.wal.Log(rec2); err != nil {
+				return fmt.Errorf("log custom bucket histograms: %w", err)
+			}
+		}
+	}
 	if len(a.floatHistograms) > 0 {
-		rec = enc.FloatHistogramSamples(a.floatHistograms, buf)
+		rec1, rec2 := enc.FloatHistogramSamples(a.floatHistograms, buf)
-		buf = rec[:0]
+		//rec = append(rec1, rec2...)
-		if err := a.head.wal.Log(rec); err != nil {
+		//
+		//buf = rec[:0]
+		//
+		//if err := a.head.wal.Log(rec); err != nil {
+		//	return fmt.Errorf("log samples: %w", err)
+		//}
+		if len(rec1) != 0 {
+			buf = rec1[:0]
+			if err := a.head.wal.Log(rec1); err != nil {
 				return fmt.Errorf("log float histograms: %w", err)
 			}
 		}
+		if len(rec2) != 0 {
+			buf = rec2[:0]
+			if err := a.head.wal.Log(rec2); err != nil {
+				return fmt.Errorf("log custom bucket float histograms: %w", err)
+			}
+		}
+	}
 	// Exemplars should be logged after samples (float/native histogram/etc),
 	// otherwise it might happen that we send the exemplars in a remote write
 	// batch before the samples, which in turn means the exemplar is rejected

tsdb/head_test.go

@@ -740,6 +740,89 @@ func TestHead_ReadWAL(t *testing.T) {
 	}
 }
 
+func TestHead_ReadWAL2(t *testing.T) {
+	for _, compress := range []wlog.CompressionType{wlog.CompressionNone, wlog.CompressionSnappy, wlog.CompressionZstd} {
+		t.Run(fmt.Sprintf("compress=%s", compress), func(t *testing.T) {
+			entries := []interface{}{
+				[]record.RefSeries{
+					{Ref: 10, Labels: labels.FromStrings("a", "1")},
+					{Ref: 11, Labels: labels.FromStrings("a", "2")},
+					{Ref: 100, Labels: labels.FromStrings("a", "3")},
+				},
+				[]record.RefHistogramSample{
+					{Ref: 0, T: 99, H: tsdbutil.GenerateTestHistogram(1)},
+					{Ref: 10, T: 100, H: tsdbutil.GenerateTestCustomBucketsHistogram(2)},
+					{Ref: 100, T: 100, H: tsdbutil.GenerateTestHistogram(3)},
+				},
+				[]record.RefSeries{
+					{Ref: 50, Labels: labels.FromStrings("a", "4")},
+					// This series has two refs pointing to it.
+					{Ref: 101, Labels: labels.FromStrings("a", "3")},
+				},
+				[]record.RefHistogramSample{
+					{Ref: 10, T: 101, H: tsdbutil.GenerateTestHistogram(5)},
+					{Ref: 50, T: 101, H: tsdbutil.GenerateTestHistogram(6)},
+					{Ref: 101, T: 101, H: tsdbutil.GenerateTestCustomBucketsHistogram(7)},
+				},
+				[]tombstones.Stone{
+					{Ref: 0, Intervals: []tombstones.Interval{{Mint: 99, Maxt: 101}}},
+				},
+				[]record.RefExemplar{
+					{Ref: 10, T: 100, V: 1, Labels: labels.FromStrings("trace_id", "asdf")},
+				},
+			}
+
+			head, w := newTestHead(t, 1000, compress, false)
+			defer func() {
+				require.NoError(t, head.Close())
+			}()
+
+			populateTestWL(t, w, entries)
+
+			require.NoError(t, head.Init(math.MinInt64))
+			require.Equal(t, uint64(101), head.lastSeriesID.Load())
+
+			s10 := head.series.getByID(10)
+			s11 := head.series.getByID(11)
+			s50 := head.series.getByID(50)
+			s100 := head.series.getByID(100)
+
+			testutil.RequireEqual(t, labels.FromStrings("a", "1"), s10.lset)
+			require.Nil(t, s11) // Series without samples should be garbage collected at head.Init().
+			testutil.RequireEqual(t, labels.FromStrings("a", "4"), s50.lset)
+			testutil.RequireEqual(t, labels.FromStrings("a", "3"), s100.lset)
+
+			expandChunk := func(c chunkenc.Iterator) (x []sample) {
+				for c.Next() == chunkenc.ValHistogram {
+					t, v := c.AtHistogram(nil)
+					//t, v := c.At()
+					x = append(x, sample{t: t, h: v})
+				}
+				require.NoError(t, c.Err())
+				return x
+			}
+
+			c, _, _, err := s10.chunk(0, head.chunkDiskMapper, &head.memChunkPool)
+			require.NoError(t, err)
+			require.Equal(t, []sample{{100, 0, tsdbutil.GenerateTestCustomBucketsHistogram(2), nil}, {101, 0, tsdbutil.GenerateTestCustomBucketsHistogram(5), nil}}, expandChunk(c.chunk.Iterator(nil)))
+			c, _, _, err = s50.chunk(0, head.chunkDiskMapper, &head.memChunkPool)
+			require.NoError(t, err)
+			require.Equal(t, []sample{{101, 0, tsdbutil.GenerateTestHistogram(6), nil}}, expandChunk(c.chunk.Iterator(nil)))
+			// The samples before the new series record should be discarded since a duplicate record
+			// is only possible when old samples were compacted.
+			c, _, _, err = s100.chunk(0, head.chunkDiskMapper, &head.memChunkPool)
+			require.NoError(t, err)
+			require.Equal(t, []sample{{101, 0, tsdbutil.GenerateTestCustomBucketsHistogram(7), nil}}, expandChunk(c.chunk.Iterator(nil)))
+
+			q, err := head.ExemplarQuerier(context.Background())
+			require.NoError(t, err)
+			e, err := q.Select(0, 1000, []*labels.Matcher{labels.MustNewMatcher(labels.MatchEqual, "a", "1")})
+			require.NoError(t, err)
+			require.True(t, exemplar.Exemplar{Ts: 100, Value: 1, Labels: labels.FromStrings("trace_id", "asdf")}.Equals(e[0].Exemplars[0]))
+		})
+	}
+}
+
 func TestHead_WALMultiRef(t *testing.T) {
 	head, w := newTestHead(t, 1000, wlog.CompressionNone, false)
 
@@ -3953,6 +4036,194 @@ func TestHistogramInWALAndMmapChunk(t *testing.T) {
 	testQuery()
 }
 
+func TestHistogramInWALAndMmapChunk2(t *testing.T) {
+	head, _ := newTestHead(t, 3000, wlog.CompressionNone, false)
+	t.Cleanup(func() {
+		require.NoError(t, head.Close())
+	})
+	require.NoError(t, head.Init(0))
+
+	// Series with only histograms.
+	s1 := labels.FromStrings("a", "b1")
+	k1 := s1.String()
+	numHistograms := 300
+	exp := map[string][]chunks.Sample{}
+	ts := int64(0)
+	var app storage.Appender
+	for _, custom := range []bool{true, false} {
+		app = head.Appender(context.Background())
+		var hists []*histogram.Histogram
+		if custom {
+			hists = tsdbutil.GenerateTestCustomBucketsHistograms(numHistograms)
+		} else {
+			hists = tsdbutil.GenerateTestHistograms(numHistograms)
+		}
+		for _, h := range hists {
+			if !custom {
+				h.NegativeSpans = h.PositiveSpans
+				h.NegativeBuckets = h.PositiveBuckets
+			}
+			_, err := app.AppendHistogram(0, s1, ts, h, nil)
+			require.NoError(t, err)
+			exp[k1] = append(exp[k1], sample{t: ts, h: h.Copy()})
+			ts++
+			if ts%5 == 0 {
+				require.NoError(t, app.Commit())
+				app = head.Appender(context.Background())
+			}
+		}
+		require.NoError(t, app.Commit())
+	}
+	for _, custom := range []bool{true, false} {
+		app = head.Appender(context.Background())
+		var hists []*histogram.FloatHistogram
+		if custom {
+			hists = tsdbutil.GenerateTestCustomBucketsFloatHistograms(numHistograms)
+		} else {
+			hists = tsdbutil.GenerateTestFloatHistograms(numHistograms)
+		}
+		for _, h := range hists {
+			if !custom {
+				h.NegativeSpans = h.PositiveSpans
+				h.NegativeBuckets = h.PositiveBuckets
+			}
+			_, err := app.AppendHistogram(0, s1, ts, nil, h)
+			require.NoError(t, err)
+			exp[k1] = append(exp[k1], sample{t: ts, fh: h.Copy()})
+			ts++
+			if ts%5 == 0 {
+				require.NoError(t, app.Commit())
+				app = head.Appender(context.Background())
+			}
+		}
+		require.NoError(t, app.Commit())
+		head.mmapHeadChunks()
+	}
+
+	// There should be 20 mmap chunks in s1.
+	ms := head.series.getByHash(s1.Hash(), s1)
+	require.Len(t, ms.mmappedChunks, 19)
+	expMmapChunks := make([]*mmappedChunk, 0, 20)
+	for _, mmap := range ms.mmappedChunks {
+		require.Positive(t, mmap.numSamples)
+		cpy := *mmap
+		expMmapChunks = append(expMmapChunks, &cpy)
+	}
+	expHeadChunkSamples := ms.headChunks.chunk.NumSamples()
+	require.Positive(t, expHeadChunkSamples)
+
+	// Series with mix of histograms and float.
+	s2 := labels.FromStrings("a", "b2")
+	k2 := s2.String()
+	ts = 0
+	for _, custom := range []bool{true, false} {
+		app = head.Appender(context.Background())
+		var hists []*histogram.Histogram
+		if custom {
+			hists = tsdbutil.GenerateTestCustomBucketsHistograms(100)
+		} else {
+			hists = tsdbutil.GenerateTestHistograms(100)
+		}
+		for _, h := range hists {
+			ts++
+			if !custom {
+				h.NegativeSpans = h.PositiveSpans
+				h.NegativeBuckets = h.PositiveBuckets
+			}
+			_, err := app.AppendHistogram(0, s2, ts, h, nil)
+			require.NoError(t, err)
+			eh := h.Copy()
+			if ts > 30 && (ts-10)%20 == 1 {
+				// Need "unknown" hint after float sample.
+				eh.CounterResetHint = histogram.UnknownCounterReset
+			}
+			exp[k2] = append(exp[k2], sample{t: ts, h: eh})
+			if ts%20 == 0 {
+				require.NoError(t, app.Commit())
+				app = head.Appender(context.Background())
+				// Add some float.
+				for i := 0; i < 10; i++ {
+					ts++
+					_, err := app.Append(0, s2, ts, float64(ts))
+					require.NoError(t, err)
+					exp[k2] = append(exp[k2], sample{t: ts, f: float64(ts)})
+				}
+				require.NoError(t, app.Commit())
+				app = head.Appender(context.Background())
+			}
+		}
+		require.NoError(t, app.Commit())
+	}
+	for _, custom := range []bool{true, false} {
+		app = head.Appender(context.Background())
+		var hists []*histogram.FloatHistogram
+		if custom {
+			hists = tsdbutil.GenerateTestCustomBucketsFloatHistograms(100)
+		} else {
+			hists = tsdbutil.GenerateTestFloatHistograms(100)
+		}
+		for _, h := range hists {
+			ts++
+			if !custom {
+				h.NegativeSpans = h.PositiveSpans
+				h.NegativeBuckets = h.PositiveBuckets
+			}
+			_, err := app.AppendHistogram(0, s2, ts, nil, h)
+			require.NoError(t, err)
+			eh := h.Copy()
+			if ts > 30 && (ts-10)%20 == 1 {
+				// Need "unknown" hint after float sample.
+				eh.CounterResetHint = histogram.UnknownCounterReset
+			}
+			exp[k2] = append(exp[k2], sample{t: ts, fh: eh})
+			if ts%20 == 0 {
+				require.NoError(t, app.Commit())
+				app = head.Appender(context.Background())
+				// Add some float.
+				for i := 0; i < 10; i++ {
+					ts++
+					_, err := app.Append(0, s2, ts, float64(ts))
+					require.NoError(t, err)
+					exp[k2] = append(exp[k2], sample{t: ts, f: float64(ts)})
+				}
+				require.NoError(t, app.Commit())
+				app = head.Appender(context.Background())
+			}
+		}
+		require.NoError(t, app.Commit())
+	}
+
+	// Restart head.
+	require.NoError(t, head.Close())
+	startHead := func() {
+		w, err := wlog.NewSize(nil, nil, head.wal.Dir(), 32768, wlog.CompressionNone)
+		require.NoError(t, err)
+		head, err = NewHead(nil, nil, w, nil, head.opts, nil)
+		require.NoError(t, err)
+		require.NoError(t, head.Init(0))
+	}
+	startHead()
+
+	// Checking contents of s1.
+	ms = head.series.getByHash(s1.Hash(), s1)
+	require.Equal(t, expMmapChunks, ms.mmappedChunks)
+	require.Equal(t, expHeadChunkSamples, ms.headChunks.chunk.NumSamples())
+
+	testQuery := func() {
+		q, err := NewBlockQuerier(head, head.MinTime(), head.MaxTime())
+		require.NoError(t, err)
+		act := query(t, q, labels.MustNewMatcher(labels.MatchRegexp, "a", "b.*"))
+		compareSeries(t, exp, act)
+	}
+	testQuery()
+
+	// Restart with no mmap chunks to test WAL replay.
+	require.NoError(t, head.Close())
+	require.NoError(t, os.RemoveAll(mmappedChunksDir(head.opts.ChunkDirRoot)))
+	startHead()
+	testQuery()
+}
+
 func TestChunkSnapshot(t *testing.T) {
 	head, _ := newTestHead(t, 120*4, wlog.CompressionNone, false)
 	defer func() {
@@ -5089,6 +5360,48 @@ func TestChunkSnapshotTakenAfterIncompleteSnapshot(t *testing.T) {
 	require.Positive(t, offset)
 }
 
+func TestHistogramWALANDWBLReplay(t *testing.T) {
+	dir := t.TempDir()
+	wal, err := wlog.NewSize(nil, nil, filepath.Join(dir, "wal"), 32768, wlog.CompressionSnappy)
+	require.NoError(t, err)
+	oooWlog, err := wlog.NewSize(nil, nil, filepath.Join(dir, wlog.WblDirName), 32768, wlog.CompressionSnappy)
+	require.NoError(t, err)
+
+	opts := DefaultHeadOptions()
+	opts.ChunkRange = 1000
+	opts.ChunkDirRoot = dir
+	opts.OutOfOrderTimeWindow.Store(30 * time.Minute.Milliseconds())
+	opts.EnableNativeHistograms.Store(true)
+	opts.EnableOOONativeHistograms.Store(true)
+
+	h, err := NewHead(nil, nil, wal, oooWlog, opts, nil)
+	require.NoError(t, err)
+	require.NoError(t, h.Init(0))
+
+	var expOOOSamples []chunks.Sample
+	l := labels.FromStrings("foo", "bar")
+	appendSample := func(mins int64, val float64, isOOO bool, isCustomBucketHistogram bool) {
+		app := h.Appender(context.Background())
+		var s sample
+		if isCustomBucketHistogram {
+			s = sample{t: mins * time.Minute.Milliseconds(), h: tsdbutil.GenerateTestCustomBucketsHistogram(int(val))}
+		} else {
+			s = sample{t: mins * time.Minute.Milliseconds(), h: tsdbutil.GenerateTestHistogram(int(val))}
+		}
+		_, err := app.AppendHistogram(0, l, mins*time.Minute.Milliseconds(), s.h, nil)
+		require.NoError(t, err)
+		require.NoError(t, app.Commit())
+
+		if isOOO {
+			expOOOSamples = append(expOOOSamples, s)
+		}
+	}
+
+	// In-order histogram samples.
+	appendSample(60, 60, false, false)
+
+}
+
 // TestWBLReplay checks the replay at a low level.
 func TestWBLReplay(t *testing.T) {
 	for name, scenario := range sampleTypeScenarios {

tsdb/head_wal.go

@@ -139,7 +139,8 @@ func (h *Head) loadWAL(r *wlog.Reader, syms *labels.SymbolTable, multiRef map[ch
 		dec := record.NewDecoder(syms)
 		for r.Next() {
 			rec := r.Record()
-			switch dec.Type(rec) {
+			recType := dec.Type(rec)
+			switch recType {
 			case record.Series:
 				series := seriesPool.Get()[:0]
 				series, err = dec.Series(rec, series)
@@ -188,7 +189,7 @@ func (h *Head) loadWAL(r *wlog.Reader, syms *labels.SymbolTable, multiRef map[ch
 					return
 				}
 				decoded <- exemplars
-			case record.HistogramSamples:
+			case record.HistogramSamples, record.CustomBucketHistogramSamples:
 				hists := histogramsPool.Get()[:0]
 				hists, err = dec.HistogramSamples(rec, hists)
 				if err != nil {
@@ -200,7 +201,7 @@ func (h *Head) loadWAL(r *wlog.Reader, syms *labels.SymbolTable, multiRef map[ch
 					return
 				}
 				decoded <- hists
-			case record.FloatHistogramSamples:
+			case record.FloatHistogramSamples, record.CustomBucketFloatHistogramSamples:
 				hists := floatHistogramsPool.Get()[:0]
 				hists, err = dec.FloatHistogramSamples(rec, hists)
 				if err != nil {

tsdb/record/record.go

@@ -52,6 +52,10 @@ const (
 	HistogramSamples Type = 7
 	// FloatHistogramSamples is used to match WAL records of type Float Histograms.
 	FloatHistogramSamples Type = 8
+	// CustomBucketHistogramSamples is used to match WAL records of type Histogram with custom buckets.
+	CustomBucketHistogramSamples Type = 9
+	// CustomBucketFloatHistogramSamples is used to match WAL records of type Float Histogram with custom buckets.
+	CustomBucketFloatHistogramSamples Type = 10
 )
 
 func (rt Type) String() string {
@@ -68,6 +72,10 @@ func (rt Type) String() string {
 		return "histogram_samples"
 	case FloatHistogramSamples:
 		return "float_histogram_samples"
+	case CustomBucketHistogramSamples:
+		return "custom_bucket_histogram_samples"
+	case CustomBucketFloatHistogramSamples:
+		return "custom_bucket_float_histogram_samples"
 	case MmapMarkers:
 		return "mmapmarkers"
 	case Metadata:
@@ -185,6 +193,10 @@ type RefFloatHistogramSample struct {
 	FH  *histogram.FloatHistogram
 }
 
+type RefCustomBucketHistogramSample struct {
+	RefHistogramSample
+}
+
 // RefMmapMarker marks that the all the samples of the given series until now have been m-mapped to disk.
 type RefMmapMarker struct {
 	Ref     chunks.HeadSeriesRef
@@ -207,7 +219,7 @@ func (d *Decoder) Type(rec []byte) Type {
 		return Unknown
 	}
 	switch t := Type(rec[0]); t {
-	case Series, Samples, Tombstones, Exemplars, MmapMarkers, Metadata, HistogramSamples, FloatHistogramSamples:
+	case Series, Samples, Tombstones, Exemplars, MmapMarkers, Metadata, HistogramSamples, FloatHistogramSamples, CustomBucketHistogramSamples, CustomBucketFloatHistogramSamples:
 		return t
 	}
 	return Unknown
@@ -428,7 +440,7 @@ func (d *Decoder) MmapMarkers(rec []byte, markers []RefMmapMarker) ([]RefMmapMar
 func (d *Decoder) HistogramSamples(rec []byte, histograms []RefHistogramSample) ([]RefHistogramSample, error) {
 	dec := encoding.Decbuf{B: rec}
 	t := Type(dec.Byte())
-	if t != HistogramSamples {
+	if t != HistogramSamples && t != CustomBucketHistogramSamples {
 		return nil, errors.New("invalid record type")
 	}
 	if dec.Len() == 0 {
@@ -508,7 +520,6 @@ func DecodeHistogram(buf *encoding.Decbuf, h *histogram.Histogram) {
 
 	if histogram.IsCustomBucketsSchema(h.Schema) {
 		l = buf.Uvarint()
-		if l > 0 {
 		if l > 0 {
 			h.CustomValues = make([]float64, l)
 		}
@@ -516,13 +527,12 @@ func DecodeHistogram(buf *encoding.Decbuf, h *histogram.Histogram) {
 			h.CustomValues[i] = buf.Be64Float64()
 		}
 	}
-	}
 }
 
 func (d *Decoder) FloatHistogramSamples(rec []byte, histograms []RefFloatHistogramSample) ([]RefFloatHistogramSample, error) {
 	dec := encoding.Decbuf{B: rec}
 	t := Type(dec.Byte())
-	if t != FloatHistogramSamples {
+	if t != FloatHistogramSamples && t != CustomBucketFloatHistogramSamples {
 		return nil, errors.New("invalid record type")
 	}
 	if dec.Len() == 0 {
@@ -602,7 +612,6 @@ func DecodeFloatHistogram(buf *encoding.Decbuf, fh *histogram.FloatHistogram) {
 
 	if histogram.IsCustomBucketsSchema(fh.Schema) {
 		l = buf.Uvarint()
-		if l > 0 {
 		if l > 0 {
 			fh.CustomValues = make([]float64, l)
 		}
@@ -610,7 +619,6 @@ func DecodeFloatHistogram(buf *encoding.Decbuf, fh *histogram.FloatHistogram) {
 			fh.CustomValues[i] = buf.Be64Float64()
 		}
 	}
-	}
 }
 
 // Encoder encodes series, sample, and tombstones records.
@@ -740,12 +748,15 @@ func (e *Encoder) MmapMarkers(markers []RefMmapMarker, b []byte) []byte {
 	return buf.Get()
 }
 
-func (e *Encoder) HistogramSamples(histograms []RefHistogramSample, b []byte) []byte {
+func (e *Encoder) HistogramSamples(histograms []RefHistogramSample, b []byte) ([]byte, []byte) {
 	buf := encoding.Encbuf{B: b}
 	buf.PutByte(byte(HistogramSamples))
 
+	customBucketHistBuf := encoding.Encbuf{B: b}
+	customBucketHistBuf.PutByte(byte(CustomBucketHistogramSamples))
+
 	if len(histograms) == 0 {
-		return buf.Get()
+		return buf.Get(), customBucketHistBuf.Get()
 	}
 
 	// Store base timestamp and base reference number of first histogram.
@@ -754,14 +765,34 @@ func (e *Encoder) HistogramSamples(histograms []RefHistogramSample, b []byte) []
 	buf.PutBE64(uint64(first.Ref))
 	buf.PutBE64int64(first.T)
 
+	customBucketHistBuf.PutBE64(uint64(first.Ref))
+	customBucketHistBuf.PutBE64int64(first.T)
+
+	histsAdded := 0
+	customBucketHistsAdded := 0
 	for _, h := range histograms {
+		if h.H.UsesCustomBuckets() {
+			customBucketHistBuf.PutVarint64(int64(h.Ref) - int64(first.Ref))
+			customBucketHistBuf.PutVarint64(h.T - first.T)
+
+			EncodeHistogram(&customBucketHistBuf, h.H)
+			customBucketHistsAdded++
+		} else {
 			buf.PutVarint64(int64(h.Ref) - int64(first.Ref))
 			buf.PutVarint64(h.T - first.T)
 
 			EncodeHistogram(&buf, h.H)
+			histsAdded++
+		}
 	}
 
-	return buf.Get()
+	if customBucketHistsAdded == 0 {
+		customBucketHistBuf.Reset()
+	} else if histsAdded == 0 {
+		buf.Reset()
+	}
+
+	return buf.Get(), customBucketHistBuf.Get()
 }
 
 // EncodeHistogram encodes a Histogram into a byte slice.
@@ -805,12 +836,15 @@ func EncodeHistogram(buf *encoding.Encbuf, h *histogram.Histogram) {
 	}
 }
 
-func (e *Encoder) FloatHistogramSamples(histograms []RefFloatHistogramSample, b []byte) []byte {
+func (e *Encoder) FloatHistogramSamples(histograms []RefFloatHistogramSample, b []byte) ([]byte, []byte) {
 	buf := encoding.Encbuf{B: b}
 	buf.PutByte(byte(FloatHistogramSamples))
 
+	customBucketHistBuf := encoding.Encbuf{B: b}
+	customBucketHistBuf.PutByte(byte(CustomBucketFloatHistogramSamples))
+
 	if len(histograms) == 0 {
-		return buf.Get()
+		return buf.Get(), customBucketHistBuf.Get()
 	}
 
 	// Store base timestamp and base reference number of first histogram.
@@ -819,14 +853,34 @@ func (e *Encoder) FloatHistogramSamples(histograms []RefFloatHistogramSample, b
 	buf.PutBE64(uint64(first.Ref))
 	buf.PutBE64int64(first.T)
 
+	customBucketHistBuf.PutBE64(uint64(first.Ref))
+	customBucketHistBuf.PutBE64int64(first.T)
+
+	histsAdded := 0
+	customBucketHistsAdded := 0
 	for _, h := range histograms {
+		if h.FH.UsesCustomBuckets() {
+			customBucketHistBuf.PutVarint64(int64(h.Ref) - int64(first.Ref))
+			customBucketHistBuf.PutVarint64(h.T - first.T)
+
+			EncodeFloatHistogram(&customBucketHistBuf, h.FH)
+			customBucketHistsAdded++
+		} else {
 			buf.PutVarint64(int64(h.Ref) - int64(first.Ref))
 			buf.PutVarint64(h.T - first.T)
 
 			EncodeFloatHistogram(&buf, h.FH)
+			histsAdded++
+		}
 	}
 
-	return buf.Get()
+	if customBucketHistsAdded == 0 {
+		customBucketHistBuf.Reset()
+	} else if histsAdded == 0 {
+		buf.Reset()
+	}
+
+	return buf.Get(), customBucketHistBuf.Get()
 }
 
 // EncodeFloatHistogram encodes the Float Histogram into a byte slice.

tsdb/record/record_test.go

@@ -148,10 +148,30 @@ func TestRecord_EncodeDecode(t *testing.T) {
 				NegativeBuckets: []int64{1, 2, -1},
 			},
 		},
+		{
+			Ref: 67,
+			T:   5678,
+			H: &histogram.Histogram{
+				Count:         8,
+				ZeroThreshold: 0.001,
+				Sum:           35.5,
+				Schema:        -53,
+				PositiveSpans: []histogram.Span{
+					{Offset: 0, Length: 2},
+					{Offset: 2, Length: 2},
+				},
+				PositiveBuckets: []int64{2, -1, 2, 0},
+				CustomValues:    []float64{0, 2, 4, 6, 8},
+			},
+		},
 	}
 
-	decHistograms, err := dec.HistogramSamples(enc.HistogramSamples(histograms, nil), nil)
+	histSamples, customBucketHistSamples := enc.HistogramSamples(histograms, nil)
+	decHistograms, err := dec.HistogramSamples(histSamples, nil)
 	require.NoError(t, err)
+	decCustomBucketHistograms, err := dec.HistogramSamples(customBucketHistSamples, nil)
+	require.NoError(t, err)
+	decHistograms = append(decHistograms, decCustomBucketHistograms...)
 	require.Equal(t, histograms, decHistograms)
 
 	floatHistograms := make([]RefFloatHistogramSample, len(histograms))
@@ -162,24 +182,36 @@ func TestRecord_EncodeDecode(t *testing.T) {
 			FH:  h.H.ToFloat(nil),
 		}
 	}
-	decFloatHistograms, err := dec.FloatHistogramSamples(enc.FloatHistogramSamples(floatHistograms, nil), nil)
+	histSamples, customBucketFloatHistSamples := enc.FloatHistogramSamples(floatHistograms, nil)
+	decFloatHistograms, err := dec.FloatHistogramSamples(histSamples, nil)
 	require.NoError(t, err)
+	decCustomBucketFloatHistograms, err := dec.FloatHistogramSamples(customBucketFloatHistSamples, nil)
+	decFloatHistograms = append(decFloatHistograms, decCustomBucketFloatHistograms...)
 	require.Equal(t, floatHistograms, decFloatHistograms)
 
 	// Gauge integer histograms.
 	for i := range histograms {
 		histograms[i].H.CounterResetHint = histogram.GaugeType
 	}
-	decHistograms, err = dec.HistogramSamples(enc.HistogramSamples(histograms, nil), nil)
+
+	gaugeHistSamples, customBucketGaugeHistSamples := enc.HistogramSamples(histograms, nil)
+	decGaugeHistograms, err := dec.HistogramSamples(gaugeHistSamples, nil)
 	require.NoError(t, err)
-	require.Equal(t, histograms, decHistograms)
+	decCustomBucketGaugeHistograms, err := dec.HistogramSamples(customBucketGaugeHistSamples, nil)
+	require.NoError(t, err)
+	decGaugeHistograms = append(decGaugeHistograms, decCustomBucketGaugeHistograms...)
+	require.Equal(t, histograms, decGaugeHistograms)
 
 	// Gauge float histograms.
 	for i := range floatHistograms {
 		floatHistograms[i].FH.CounterResetHint = histogram.GaugeType
 	}
-	decFloatHistograms, err = dec.FloatHistogramSamples(enc.FloatHistogramSamples(floatHistograms, nil), nil)
+
+	gaugeHistSamples, customBucketGaugeFloatHistSamples := enc.FloatHistogramSamples(floatHistograms, nil)
+	decGaugeFloatHistograms, err := dec.FloatHistogramSamples(gaugeHistSamples, nil)
 	require.NoError(t, err)
+	decCustomBucketGaugeFloatHistograms, err := dec.FloatHistogramSamples(customBucketGaugeFloatHistSamples, nil)
+	decFloatHistograms = append(decGaugeFloatHistograms, decCustomBucketGaugeFloatHistograms...)
 	require.Equal(t, floatHistograms, decFloatHistograms)
 }
 
@@ -265,8 +297,12 @@ func TestRecord_Corrupted(t *testing.T) {
 			},
 		}
 
-		corrupted := enc.HistogramSamples(histograms, nil)[:8]
+		corruptedHists, corruptedCustomBucketHists := enc.HistogramSamples(histograms, nil)
-		_, err := dec.HistogramSamples(corrupted, nil)
+		corruptedHists = corruptedHists[:8]
+		corruptedCustomBucketHists = corruptedCustomBucketHists[:8]
+		_, err := dec.HistogramSamples(corruptedHists, nil)
+		require.ErrorIs(t, err, encoding.ErrInvalidSize)
+		_, err = dec.HistogramSamples(corruptedCustomBucketHists, nil)
 		require.ErrorIs(t, err, encoding.ErrInvalidSize)
 	})
 }
@@ -308,9 +344,28 @@ func TestRecord_Type(t *testing.T) {
 				PositiveBuckets: []int64{1, 1, -1, 0},
 			},
 		},
+		{
+			Ref: 67,
+			T:   5678,
+			H: &histogram.Histogram{
+				Count:         8,
+				ZeroThreshold: 0.001,
+				Sum:           35.5,
+				Schema:        -53,
+				PositiveSpans: []histogram.Span{
+					{Offset: 0, Length: 2},
+					{Offset: 2, Length: 2},
+				},
+				PositiveBuckets: []int64{2, -1, 2, 0},
+				CustomValues:    []float64{0, 2, 4, 6, 8},
+			},
+		},
 	}
-	recordType = dec.Type(enc.HistogramSamples(histograms, nil))
+	hists, customBucketHists := enc.HistogramSamples(histograms, nil)
+	recordType = dec.Type(hists)
 	require.Equal(t, HistogramSamples, recordType)
+	recordType = dec.Type(customBucketHists)
+	require.Equal(t, CustomBucketHistogramSamples, recordType)
 
 	recordType = dec.Type(nil)
 	require.Equal(t, Unknown, recordType)

tsdb/testutil.go

@@ -32,6 +32,8 @@ const (
 	float                      = "float"
 	intHistogram               = "integer histogram"
 	floatHistogram             = "float histogram"
+	customBucketIntHistogram   = "custom bucket int histogram"
+	customBucketFloatHistogram = "custom bucket float histogram"
 	gaugeIntHistogram          = "gauge int histogram"
 	gaugeFloatHistogram        = "gauge float histogram"
 )
@@ -82,6 +84,28 @@ var sampleTypeScenarios = map[string]sampleTypeScenario{
 			return sample{t: ts, fh: tsdbutil.GenerateTestFloatHistogram(int(value))}
 		},
 	},
+	customBucketIntHistogram: {
+		sampleType: sampleMetricTypeHistogram,
+		appendFunc: func(appender storage.Appender, lbls labels.Labels, ts, value int64) (storage.SeriesRef, sample, error) {
+			s := sample{t: ts, h: tsdbutil.GenerateTestCustomBucketsHistogram(int(value))}
+			ref, err := appender.AppendHistogram(0, lbls, ts, s.h, nil)
+			return ref, s, err
+		},
+		sampleFunc: func(ts, value int64) sample {
+			return sample{t: ts, h: tsdbutil.GenerateTestCustomBucketsHistogram(int(value))}
+		},
+	},
+	customBucketFloatHistogram: {
+		sampleType: sampleMetricTypeHistogram,
+		appendFunc: func(appender storage.Appender, lbls labels.Labels, ts, value int64) (storage.SeriesRef, sample, error) {
+			s := sample{t: ts, fh: tsdbutil.GenerateTestCustomBucketsFloatHistogram(int(value))}
+			ref, err := appender.AppendHistogram(0, lbls, ts, nil, s.fh)
+			return ref, s, err
+		},
+		sampleFunc: func(ts, value int64) sample {
+			return sample{t: ts, fh: tsdbutil.GenerateTestCustomBucketsFloatHistogram(int(value))}
+		},
+	},
 	gaugeIntHistogram: {
 		sampleType: sampleMetricTypeHistogram,
 		appendFunc: func(appender storage.Appender, lbls labels.Labels, ts, value int64) (storage.SeriesRef, sample, error) {

tsdb/tsdbutil/histogram.go

@@ -57,6 +57,18 @@ func GenerateTestHistogram(i int) *histogram.Histogram {
 	}
 }
 
+func GenerateTestCustomBucketsHistograms(n int) (r []*histogram.Histogram) {
+	for i := 0; i < n; i++ {
+		h := GenerateTestCustomBucketsHistogram(i)
+		if i > 0 {
+			h.CounterResetHint = histogram.NotCounterReset
+		}
+		r = append(r, h)
+
+	}
+	return r
+}
+
 func GenerateTestCustomBucketsHistogram(i int) *histogram.Histogram {
 	return &histogram.Histogram{
 		Count:  5 + uint64(i*4),
@@ -117,6 +129,17 @@ func GenerateTestFloatHistogram(i int) *histogram.FloatHistogram {
 	}
 }
 
+func GenerateTestCustomBucketsFloatHistograms(n int) (r []*histogram.FloatHistogram) {
+	for i := 0; i < n; i++ {
+		h := GenerateTestCustomBucketsFloatHistogram(i)
+		if i > 0 {
+			h.CounterResetHint = histogram.NotCounterReset
+		}
+		r = append(r, h)
+	}
+	return r
+}
+
 func GenerateTestCustomBucketsFloatHistogram(i int) *histogram.FloatHistogram {
 	return &histogram.FloatHistogram{
 		Count:  5 + float64(i*4),

tsdb/wlog/checkpoint.go

@@ -221,11 +221,27 @@ func Checkpoint(logger *slog.Logger, w *WL, from, to int, keep func(id chunks.He
 				}
 			}
 			if len(repl) > 0 {
-				buf = enc.HistogramSamples(repl, buf)
+				buf, _ = enc.HistogramSamples(repl, buf)
+			}
+			stats.TotalSamples += len(histogramSamples)
+			stats.DroppedSamples += len(histogramSamples) - len(repl)
+		case record.CustomBucketHistogramSamples:
+			histogramSamples, err = dec.HistogramSamples(rec, histogramSamples)
+			if err != nil {
+				return nil, fmt.Errorf("decode histogram samples: %w", err)
+			}
+			// Drop irrelevant histogramSamples in place.
+			repl := histogramSamples[:0]
+			for _, h := range histogramSamples {
+				if h.T >= mint {
+					repl = append(repl, h)
+				}
+			}
+			if len(repl) > 0 {
+				_, buf = enc.HistogramSamples(repl, buf)
 			}
 			stats.TotalSamples += len(histogramSamples)
 			stats.DroppedSamples += len(histogramSamples) - len(repl)
-
 		case record.FloatHistogramSamples:
 			floatHistogramSamples, err = dec.FloatHistogramSamples(rec, floatHistogramSamples)
 			if err != nil {
@@ -239,11 +255,27 @@ func Checkpoint(logger *slog.Logger, w *WL, from, to int, keep func(id chunks.He
 				}
 			}
 			if len(repl) > 0 {
-				buf = enc.FloatHistogramSamples(repl, buf)
+				buf, _ = enc.FloatHistogramSamples(repl, buf)
+			}
+			stats.TotalSamples += len(floatHistogramSamples)
+			stats.DroppedSamples += len(floatHistogramSamples) - len(repl)
+		case record.CustomBucketFloatHistogramSamples:
+			floatHistogramSamples, err = dec.FloatHistogramSamples(rec, floatHistogramSamples)
+			if err != nil {
+				return nil, fmt.Errorf("decode float histogram samples: %w", err)
+			}
+			// Drop irrelevant floatHistogramSamples in place.
+			repl := floatHistogramSamples[:0]
+			for _, fh := range floatHistogramSamples {
+				if fh.T >= mint {
+					repl = append(repl, fh)
+				}
+			}
+			if len(repl) > 0 {
+				_, buf = enc.FloatHistogramSamples(repl, buf)
 			}
 			stats.TotalSamples += len(floatHistogramSamples)
 			stats.DroppedSamples += len(floatHistogramSamples) - len(repl)
-
 		case record.Tombstones:
 			tstones, err = dec.Tombstones(rec, tstones)
 			if err != nil {

tsdb/wlog/checkpoint_test.go

@@ -208,22 +208,24 @@ func TestCheckpoint(t *testing.T) {
 				require.NoError(t, w.Log(b))
 				samplesInWAL += 4
 				h := makeHistogram(i)
-				b = enc.HistogramSamples([]record.RefHistogramSample{
+				b1, b2 := enc.HistogramSamples([]record.RefHistogramSample{
 					{Ref: 0, T: last, H: h},
 					{Ref: 1, T: last + 10000, H: h},
 					{Ref: 2, T: last + 20000, H: h},
 					{Ref: 3, T: last + 30000, H: h},
 				}, nil)
-				require.NoError(t, w.Log(b))
+				require.NoError(t, w.Log(b1))
+				require.NoError(t, w.Log(b2))
 				histogramsInWAL += 4
 				fh := makeFloatHistogram(i)
-				b = enc.FloatHistogramSamples([]record.RefFloatHistogramSample{
+				b1, b2 = enc.FloatHistogramSamples([]record.RefFloatHistogramSample{
 					{Ref: 0, T: last, FH: fh},
 					{Ref: 1, T: last + 10000, FH: fh},
 					{Ref: 2, T: last + 20000, FH: fh},
 					{Ref: 3, T: last + 30000, FH: fh},
 				}, nil)
-				require.NoError(t, w.Log(b))
+				require.NoError(t, w.Log(b1))
+				require.NoError(t, w.Log(b2))
 				floatHistogramsInWAL += 4
 
 				b = enc.Exemplars([]record.RefExemplar{

tsdb/wlog/watcher_test.go

@@ -209,19 +209,21 @@ func TestTailSamples(t *testing.T) {
 						NegativeBuckets: []int64{int64(-i) - 1},
 					}
 
-					histogram := enc.HistogramSamples([]record.RefHistogramSample{{
+					histogram, customBucketHistogram := enc.HistogramSamples([]record.RefHistogramSample{{
 						Ref: chunks.HeadSeriesRef(inner),
 						T:   now.UnixNano() + 1,
 						H:   hist,
 					}}, nil)
 					require.NoError(t, w.Log(histogram))
+					require.NoError(t, w.Log(customBucketHistogram))
 
-					floatHistogram := enc.FloatHistogramSamples([]record.RefFloatHistogramSample{{
+					floatHistogram, floatCustomBucketHistogram := enc.FloatHistogramSamples([]record.RefFloatHistogramSample{{
 						Ref: chunks.HeadSeriesRef(inner),
 						T:   now.UnixNano() + 1,
 						FH:  hist.ToFloat(nil),
 					}}, nil)
 					require.NoError(t, w.Log(floatHistogram))
+					require.NoError(t, w.Log(floatCustomBucketHistogram))
 				}
 			}