Merge pull request #103 from Gouthamve/block-ranges

Compaction implementation for block-ranges

cmd/tsdb/main.go

@@ -113,8 +113,7 @@ func (b *writeBenchmark) run(cmd *cobra.Command, args []string) {
 	st, err := tsdb.Open(dir, nil, nil, &tsdb.Options{
 		WALFlushInterval:  200 * time.Millisecond,
 		RetentionDuration: 2 * 24 * 60 * 60 * 1000, // 1 days in milliseconds
-		MinBlockDuration:  3 * 60 * 60 * 1000,      // 3 hours in milliseconds
-		MaxBlockDuration:  27 * 60 * 60 * 1000,     // 1 days in milliseconds
+		BlockRanges:       tsdb.ExponentialBlockRanges(int64(2*time.Hour), 3, 5),
 	})
 	if err != nil {
 		exitWithError(err)

compact.go

@@ -30,6 +30,18 @@ import (
 	"github.com/prometheus/tsdb/labels"
 )
 
+// ExponentialBlockRanges returns the time ranges based on the stepSize
+func ExponentialBlockRanges(minSize int64, steps, stepSize int) []int64 {
+	ranges := make([]int64, 0, steps)
+	curRange := minSize
+	for i := 0; i < steps; i++ {
+		ranges = append(ranges, curRange)
+		curRange = curRange * int64(stepSize)
+	}
+
+	return ranges
+}
+
 // Compactor provides compaction against an underlying storage
 // of time series data.
 type Compactor interface {
@@ -87,7 +99,7 @@ func newCompactorMetrics(r prometheus.Registerer) *compactorMetrics {
 }
 
 type compactorOptions struct {
-	maxBlockRange uint64
+	blockRanges []int64
 }
 
 func newCompactor(dir string, r prometheus.Registerer, l log.Logger, opts *compactorOptions) *compactor {
@@ -133,37 +145,90 @@ func (c *compactor) Plan() ([][]string, error) {
 		return dms[i].meta.MinTime < dms[j].meta.MinTime
 	})
 
-	if len(dms) == 0 {
+	if len(dms) <= 1 {
 		return nil, nil
 	}
 
-	sliceDirs := func(i, j int) [][]string {
+	sliceDirs := func(dms []dirMeta) [][]string {
+		if len(dms) == 0 {
+			return nil
+		}
 		var res []string
-		for k := i; k < j; k++ {
-			res = append(res, dms[k].dir)
+		for _, dm := range dms {
+			res = append(res, dm.dir)
 		}
 		return [][]string{res}
 	}
 
-	// Then we care about compacting multiple blocks, starting with the oldest.
-	for i := 0; i < len(dms)-compactionBlocksLen+1; i++ {
-		if c.match(dms[i : i+3]) {
-			return sliceDirs(i, i+compactionBlocksLen), nil
-		}
-	}
-
-	return nil, nil
+	return sliceDirs(c.selectDirs(dms)), nil
 }
 
-func (c *compactor) match(dirs []dirMeta) bool {
-	g := dirs[0].meta.Compaction.Generation
+func (c *compactor) selectDirs(ds []dirMeta) []dirMeta {
+	// The way to skip compaction is to not have blockRanges.
+	if len(c.opts.blockRanges) == 1 {
+		return nil
+	}
 
-	for _, d := range dirs {
-		if d.meta.Compaction.Generation != g {
-			return false
+	return selectRecurse(ds, c.opts.blockRanges)
+}
+
+func selectRecurse(dms []dirMeta, intervals []int64) []dirMeta {
+	if len(intervals) == 0 {
+		return dms
+	}
+
+	// Get the blocks by the max interval
+	blocks := splitByRange(dms, intervals[len(intervals)-1])
+	dirs := []dirMeta{}
+	for i := len(blocks) - 1; i >= 0; i-- {
+		// We need to choose the oldest blocks to compact. If there are a couple of blocks in
+		// the largest interval, we should compact those first.
+		if len(blocks[i]) > 1 {
+			dirs = blocks[i]
+			break
 		}
 	}
-	return uint64(dirs[len(dirs)-1].meta.MaxTime-dirs[0].meta.MinTime) <= c.opts.maxBlockRange
+
+	// If there are too many blocks, see if a smaller interval will catch them.
+	// i.e, if we have 0-20, 60-80, 80-100; all fall under 0-240, but we'd rather compact 60-100
+	// than all at once.
+	// Again if have 0-1d, 1d-2d, 3-6d we compact 0-1d, 1d-2d to compact it into the 0-3d block instead of compacting all three
+	// This is to honor the boundaries as much as possible.
+	if len(dirs) > 2 {
+		smallerDirs := selectRecurse(dirs, intervals[:len(intervals)-1])
+		if len(smallerDirs) > 1 {
+			return smallerDirs
+		}
+	}
+
+	return dirs
+}
+
+// splitByRange splits the directories by the time range.
+// for example if we have blocks 0-10, 10-20, 50-60, 90-100 and want to split them into 30 interval ranges
+// splitByRange returns [0-10, 10-20], [50-60], [90-100].
+func splitByRange(ds []dirMeta, tr int64) [][]dirMeta {
+	var splitDirs [][]dirMeta
+
+	for i := 0; i < len(ds); {
+		var group []dirMeta
+		// Compute start of aligned time range of size tr closest to the current block's start.
+		t0 := ds[i].meta.MinTime - (ds[i].meta.MinTime % tr)
+
+		// Add all dirs to the current group that are within [t0, t0+tr].
+		for ; i < len(ds); i++ {
+			if ds[i].meta.MinTime < t0 || ds[i].meta.MaxTime > t0+tr {
+				break
+			}
+			group = append(group, ds[i])
+		}
+
+		if len(group) > 0 {
+			splitDirs = append(splitDirs, group)
+		}
+	}
+
+	return splitDirs
 }
 
 func compactBlockMetas(blocks ...BlockMeta) (res BlockMeta) {

compact_test.go

@@ -0,0 +1,245 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tsdb
+
+import (
+	"sort"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCompactionSelect(t *testing.T) {
+	opts := &compactorOptions{
+		blockRanges: []int64{
+			20,
+			60,
+			240,
+			720,
+			2160,
+		},
+	}
+
+	type dirMetaSimple struct {
+		dir string
+		tr  []int64
+	}
+
+	cases := []struct {
+		blocks  []dirMetaSimple
+		planned [][]string
+	}{
+		{
+			blocks: []dirMetaSimple{
+				{
+					dir: "1",
+					tr:  []int64{0, 20},
+				},
+			},
+			planned: nil,
+		},
+		{
+			blocks: []dirMetaSimple{
+				{
+					dir: "1",
+					tr:  []int64{0, 20},
+				},
+				{
+					dir: "2",
+					tr:  []int64{20, 40},
+				},
+				{
+					dir: "3",
+					tr:  []int64{40, 60},
+				},
+			},
+			planned: [][]string{{"1", "2", "3"}},
+		},
+		{
+			blocks: []dirMetaSimple{
+				{
+					dir: "1",
+					tr:  []int64{0, 20},
+				},
+				{
+					dir: "2",
+					tr:  []int64{20, 40},
+				},
+				{
+					dir: "3",
+					tr:  []int64{40, 60},
+				},
+				{
+					dir: "4",
+					tr:  []int64{60, 120},
+				},
+				{
+					dir: "5",
+					tr:  []int64{120, 180},
+				},
+			},
+			planned: [][]string{{"1", "2", "3"}}, // We still need 0-60 to compact 0-240
+		},
+		{
+			blocks: []dirMetaSimple{
+				{
+					dir: "1",
+					tr:  []int64{0, 20},
+				},
+				{
+					dir: "2",
+					tr:  []int64{20, 40},
+				},
+				{
+					dir: "3",
+					tr:  []int64{40, 60},
+				},
+				{
+					dir: "4",
+					tr:  []int64{60, 120},
+				},
+				{
+					dir: "5",
+					tr:  []int64{120, 180},
+				},
+				{
+					dir: "6",
+					tr:  []int64{720, 960},
+				},
+				{
+					dir: "7",
+					tr:  []int64{1200, 1440},
+				},
+			},
+			planned: [][]string{{"6", "7"}},
+		},
+		{
+			blocks: []dirMetaSimple{
+				{
+					dir: "1",
+					tr:  []int64{0, 20},
+				},
+				{
+					dir: "2",
+					tr:  []int64{60, 80},
+				},
+				{
+					dir: "3",
+					tr:  []int64{80, 100},
+				},
+			},
+			planned: [][]string{{"2", "3"}},
+		},
+	}
+
+	c := &compactor{
+		opts: opts,
+	}
+	sliceDirs := func(dms []dirMeta) [][]string {
+		if len(dms) == 0 {
+			return nil
+		}
+		var res []string
+		for _, dm := range dms {
+			res = append(res, dm.dir)
+		}
+		return [][]string{res}
+	}
+
+	dmFromSimple := func(dms []dirMetaSimple) []dirMeta {
+		dirs := make([]dirMeta, 0, len(dms))
+		for _, dir := range dms {
+			dirs = append(dirs, dirMeta{
+				dir: dir.dir,
+				meta: &BlockMeta{
+					MinTime: dir.tr[0],
+					MaxTime: dir.tr[1],
+				},
+			})
+		}
+
+		return dirs
+	}
+
+	for _, tc := range cases {
+		require.Equal(t, tc.planned, sliceDirs(c.selectDirs(dmFromSimple(tc.blocks))))
+	}
+}
+
+func TestSplitByRange(t *testing.T) {
+	splitterFunc := func(ds []dirMeta, tr int64) [][]dirMeta {
+		rMap := make(map[int64][]dirMeta)
+		for _, dir := range ds {
+			t0 := dir.meta.MinTime - dir.meta.MinTime%tr
+			if intervalContains(t0, t0+tr, dir.meta.MinTime) && intervalContains(t0, t0+tr, dir.meta.MaxTime) {
+				rMap[t0] = append(rMap[t0], dir)
+			}
+		}
+		res := make([][]dirMeta, 0, len(rMap))
+		for _, v := range rMap {
+			res = append(res, v)
+		}
+
+		sort.Slice(res, func(i, j int) bool {
+			return res[i][0].meta.MinTime < res[j][0].meta.MinTime
+		})
+
+		return res
+	}
+
+	cases := []struct {
+		trange int64
+		ranges [][]int64
+		output [][][]int64
+	}{
+		{
+			trange: 60,
+			ranges: [][]int64{{0, 10}},
+		},
+		{
+			trange: 60,
+			ranges: [][]int64{{0, 60}},
+		},
+		{
+			trange: 60,
+			ranges: [][]int64{{0, 10}, {30, 60}},
+		},
+		{
+			trange: 60,
+			ranges: [][]int64{{0, 10}, {60, 90}},
+		},
+		{
+			trange: 60,
+			ranges: [][]int64{{0, 10}, {20, 30}, {90, 120}},
+		},
+		{
+			trange: 60,
+			ranges: [][]int64{{0, 10}, {59, 60}, {60, 120}, {120, 180}, {190, 200}, {200, 210}, {220, 239}},
+		},
+	}
+
+	for _, c := range cases {
+		blocks := make([]dirMeta, 0, len(c.ranges))
+		for _, r := range c.ranges {
+			blocks = append(blocks, dirMeta{
+				meta: &BlockMeta{
+					MinTime: r[0],
+					MaxTime: r[1],
+				},
+			})
+		}
+
+		require.Equal(t, splitterFunc(blocks, c.trange), splitByRange(blocks, c.trange))
+	}
+}

db.go

@@ -45,8 +45,7 @@ import (
 var DefaultOptions = &Options{
 	WALFlushInterval:  5 * time.Second,
 	RetentionDuration: 15 * 24 * 60 * 60 * 1000, // 15 days in milliseconds
-	MinBlockDuration:  3 * 60 * 60 * 1000,       // 2 hours in milliseconds
-	MaxBlockDuration:  24 * 60 * 60 * 1000,      // 1 days in milliseconds
+	BlockRanges:       ExponentialBlockRanges(int64(2*time.Hour), 3, 5),
 	NoLockfile:        false,
 }
 
@@ -58,12 +57,8 @@ type Options struct {
 	// Duration of persisted data to keep.
 	RetentionDuration uint64
 
-	// The timestamp range of head blocks after which they get persisted.
-	// It's the minimum duration of any persisted block.
-	MinBlockDuration uint64
-
-	// The maximum timestamp range of compacted blocks.
-	MaxBlockDuration uint64
+	// The sizes of the Blocks.
+	BlockRanges []int64
 
 	// NoLockfile disables creation and consideration of a lock file.
 	NoLockfile bool
@@ -227,9 +222,24 @@ func Open(dir string, l log.Logger, r prometheus.Registerer, opts *Options) (db
 		db.lockf = &lockf
 	}
 
-	db.compactor = newCompactor(dir, r, l, &compactorOptions{
-		maxBlockRange: opts.MaxBlockDuration,
-	})
+	copts := &compactorOptions{
+		blockRanges: opts.BlockRanges,
+	}
+
+	if len(copts.blockRanges) == 0 {
+		return nil, errors.New("at least one block-range must exist")
+	}
+
+	for float64(copts.blockRanges[len(copts.blockRanges)-1])/float64(opts.RetentionDuration) > 0.2 {
+		if len(copts.blockRanges) == 1 {
+			break
+		}
+
+		// Max overflow is restricted to 20%.
+		copts.blockRanges = copts.blockRanges[:len(copts.blockRanges)-1]
+	}
+
+	db.compactor = newCompactor(dir, r, l, copts)
 
 	if err := db.reloadBlocks(); err != nil {
 		return nil, err
@@ -699,20 +709,20 @@ func rangeForTimestamp(t int64, width int64) (mint, maxt int64) {
 // it is within or after the currently appendable window.
 func (db *DB) ensureHead(t int64) error {
 	var (
-		mint, maxt = rangeForTimestamp(t, int64(db.opts.MinBlockDuration))
+		mint, maxt = rangeForTimestamp(t, int64(db.opts.BlockRanges[0]))
 		addBuffer  = len(db.blocks) == 0
 		last       BlockMeta
 	)
 
 	if !addBuffer {
 		last = db.blocks[len(db.blocks)-1].Meta()
-		addBuffer = last.MaxTime <= mint-int64(db.opts.MinBlockDuration)
+		addBuffer = last.MaxTime <= mint-int64(db.opts.BlockRanges[0])
 	}
 	// Create another block of buffer in front if the DB is initialized or retrieving
 	// new data after a long gap.
 	// This ensures we always have a full block width of append window.
 	if addBuffer {
-		if _, err := db.createHeadBlock(mint-int64(db.opts.MinBlockDuration), mint); err != nil {
+		if _, err := db.createHeadBlock(mint-int64(db.opts.BlockRanges[0]), mint); err != nil {
 			return err
 		}
 		// If the previous block reaches into our new window, make it smaller.