app/vmselect: optimize /api/v1/series by skipping storage data

Fetch and process only time series metainfo.

app/vmselect/netstorage/netstorage.go

@@ -47,6 +47,7 @@ func (r *Result) reset() {
 type Results struct {
 	at        *auth.Token
 	tr        storage.TimeRange
+	fetchData bool
 	deadline  Deadline
 
 	tbf *tmpBlocksFile
@@ -100,10 +101,10 @@ func (rss *Results) RunParallel(f func(rs *Result, workerID uint)) error {
 					err = fmt.Errorf("timeout exceeded during query execution: %s", rss.deadline.Timeout)
 					break
 				}
-				if err = pts.Unpack(rss.tbf, rs, rss.tr, rss.at, maxWorkersCount); err != nil {
+				if err = pts.Unpack(rss.tbf, rs, rss.tr, rss.fetchData, rss.at, maxWorkersCount); err != nil {
 					break
 				}
-				if len(rs.Timestamps) == 0 {
+				if len(rs.Timestamps) == 0 && rss.fetchData {
 					// Skip empty blocks.
 					continue
 				}
@@ -146,7 +147,7 @@ type packedTimeseries struct {
 }
 
 // Unpack unpacks pts to dst.
-func (pts *packedTimeseries) Unpack(tbf *tmpBlocksFile, dst *Result, tr storage.TimeRange, at *auth.Token, maxWorkersCount int) error {
+func (pts *packedTimeseries) Unpack(tbf *tmpBlocksFile, dst *Result, tr storage.TimeRange, fetchData bool, at *auth.Token, maxWorkersCount int) error {
 	dst.reset()
 
 	if err := dst.MetricName.Unmarshal(bytesutil.ToUnsafeBytes(pts.metricName)); err != nil {
@@ -173,7 +174,7 @@ func (pts *packedTimeseries) Unpack(tbf *tmpBlocksFile, dst *Result, tr storage.
 			var err error
 			for addr := range workCh {
 				sb := getSortBlock()
-				if err = sb.unpackFrom(tbf, addr, tr, at); err != nil {
+				if err = sb.unpackFrom(tbf, addr, tr, fetchData, at); err != nil {
 					break
 				}
 
@@ -292,11 +293,13 @@ func (sb *sortBlock) reset() {
 	sb.NextIdx = 0
 }
 
-func (sb *sortBlock) unpackFrom(tbf *tmpBlocksFile, addr tmpBlockAddr, tr storage.TimeRange, at *auth.Token) error {
+func (sb *sortBlock) unpackFrom(tbf *tmpBlocksFile, addr tmpBlockAddr, tr storage.TimeRange, fetchData bool, at *auth.Token) error {
 	tbf.MustReadBlockAt(&sb.b, addr)
+	if fetchData {
 		if err := sb.b.UnmarshalData(); err != nil {
 			return fmt.Errorf("cannot unmarshal block: %s", err)
 		}
+	}
 	timestamps := sb.b.Timestamps()
 
 	// Skip timestamps smaller than tr.MinTimestamp.
@@ -692,7 +695,7 @@ func GetSeriesCount(at *auth.Token, deadline Deadline) (uint64, bool, error) {
 }
 
 // ProcessSearchQuery performs sq on storage nodes until the given deadline.
-func ProcessSearchQuery(at *auth.Token, sq *storage.SearchQuery, deadline Deadline) (*Results, bool, error) {
+func ProcessSearchQuery(at *auth.Token, sq *storage.SearchQuery, fetchData bool, deadline Deadline) (*Results, bool, error) {
 	requestData := sq.Marshal(nil)
 
 	// Send the query to all the storage nodes in parallel.
@@ -708,7 +711,7 @@ func ProcessSearchQuery(at *auth.Token, sq *storage.SearchQuery, deadline Deadli
 	for _, sn := range storageNodes {
 		go func(sn *storageNode) {
 			sn.searchRequests.Inc()
-			results, err := sn.processSearchQuery(requestData, tr, deadline)
+			results, err := sn.processSearchQuery(requestData, tr, fetchData, deadline)
 			if err != nil {
 				sn.searchRequestErrors.Inc()
 				err = fmt.Errorf("cannot perform search on vmstorage %s: %s", sn.connPool.Addr(), err)
@@ -769,6 +772,7 @@ func ProcessSearchQuery(at *auth.Token, sq *storage.SearchQuery, deadline Deadli
 	rss.packedTimeseries = make([]packedTimeseries, len(m))
 	rss.at = at
 	rss.tr = tr
+	rss.fetchData = fetchData
 	rss.deadline = deadline
 	rss.tbf = tbf
 	i := 0
@@ -931,20 +935,20 @@ func (sn *storageNode) getSeriesCount(accountID, projectID uint32, deadline Dead
 	return n, nil
 }
 
-func (sn *storageNode) processSearchQuery(requestData []byte, tr storage.TimeRange, deadline Deadline) ([]*storage.MetricBlock, error) {
+func (sn *storageNode) processSearchQuery(requestData []byte, tr storage.TimeRange, fetchData bool, deadline Deadline) ([]*storage.MetricBlock, error) {
 	var results []*storage.MetricBlock
 	f := func(bc *handshake.BufferedConn) error {
-		rs, err := sn.processSearchQueryOnConn(bc, requestData, tr)
+		rs, err := sn.processSearchQueryOnConn(bc, requestData, tr, fetchData)
 		if err != nil {
 			return err
 		}
 		results = rs
 		return nil
 	}
-	if err := sn.execOnConn("search_v2", f, deadline); err != nil {
+	if err := sn.execOnConn("search_v3", f, deadline); err != nil {
 		// Try again before giving up.
 		results = nil
-		if err = sn.execOnConn("search_v2", f, deadline); err != nil {
+		if err = sn.execOnConn("search_v3", f, deadline); err != nil {
 			return nil, err
 		}
 	}
@@ -1197,11 +1201,14 @@ const maxMetricBlockSize = 1024 * 1024
 // from vmstorage.
 const maxErrorMessageSize = 64 * 1024
 
-func (sn *storageNode) processSearchQueryOnConn(bc *handshake.BufferedConn, requestData []byte, tr storage.TimeRange) ([]*storage.MetricBlock, error) {
+func (sn *storageNode) processSearchQueryOnConn(bc *handshake.BufferedConn, requestData []byte, tr storage.TimeRange, fetchData bool) ([]*storage.MetricBlock, error) {
 	// Send the request to sn.
 	if err := writeBytes(bc, requestData); err != nil {
 		return nil, fmt.Errorf("cannot write requestData: %s", err)
 	}
+	if err := writeBool(bc, fetchData); err != nil {
+		return nil, fmt.Errorf("cannot write fetchData=%v: %s", fetchData, err)
+	}
 	if err := bc.Flush(); err != nil {
 		return nil, fmt.Errorf("cannot flush requestData to conn: %s", err)
 	}
@@ -1265,6 +1272,17 @@ func writeUint32(bc *handshake.BufferedConn, n uint32) error {
 	return nil
 }
 
+func writeBool(bc *handshake.BufferedConn, b bool) error {
+	var buf [1]byte
+	if b {
+		buf[0] = 1
+	}
+	if _, err := bc.Write(buf[:]); err != nil {
+		return err
+	}
+	return nil
+}
+
 func readBytes(buf []byte, bc *handshake.BufferedConn, maxDataSize int) ([]byte, error) {
 	buf = bytesutil.Resize(buf, 8)
 	if _, err := io.ReadFull(bc, buf); err != nil {

app/vmselect/prometheus/prometheus.go

@@ -72,7 +72,7 @@ func FederateHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) err
 		MaxTimestamp: end,
 		TagFilterss:  tagFilterss,
 	}
-	rss, isPartial, err := netstorage.ProcessSearchQuery(at, sq, deadline)
+	rss, isPartial, err := netstorage.ProcessSearchQuery(at, sq, true, deadline)
 	if err != nil {
 		return fmt.Errorf("cannot fetch data for %q: %s", sq, err)
 	}
@@ -169,7 +169,7 @@ func exportHandler(at *auth.Token, w http.ResponseWriter, matches []string, star
 		MaxTimestamp: end,
 		TagFilterss:  tagFilterss,
 	}
-	rss, isPartial, err := netstorage.ProcessSearchQuery(at, sq, deadline)
+	rss, isPartial, err := netstorage.ProcessSearchQuery(at, sq, true, deadline)
 	if err != nil {
 		return fmt.Errorf("cannot fetch data for %q: %s", sq, err)
 	}
@@ -405,7 +405,7 @@ func SeriesHandler(at *auth.Token, w http.ResponseWriter, r *http.Request) error
 		MaxTimestamp: end,
 		TagFilterss:  tagFilterss,
 	}
-	rss, isPartial, err := netstorage.ProcessSearchQuery(at, sq, deadline)
+	rss, isPartial, err := netstorage.ProcessSearchQuery(at, sq, false, deadline)
 	if err != nil {
 		return fmt.Errorf("cannot fetch data for %q: %s", sq, err)
 	}

app/vmselect/promql/eval.go

@@ -578,8 +578,7 @@ func evalRollupFuncWithMetricExpr(ec *EvalConfig, name string, rf rollupFunc, me
 		MaxTimestamp: ec.End + ec.Step,
 		TagFilterss:  [][]storage.TagFilter{me.TagFilters},
 	}
-
+	rss, isPartial, err := netstorage.ProcessSearchQuery(ec.AuthToken, sq, true, ec.Deadline)
-	rss, isPartial, err := netstorage.ProcessSearchQuery(ec.AuthToken, sq, ec.Deadline)
 	if err != nil {
 		return nil, err
 	}

app/vmstorage/transport/server.go

@@ -392,6 +392,18 @@ func (ctx *vmselectRequestCtx) readDataBufBytes(maxDataSize int) error {
 	return nil
 }
 
+func (ctx *vmselectRequestCtx) readBool() (bool, error) {
+	ctx.dataBuf = bytesutil.Resize(ctx.dataBuf, 1)
+	if _, err := io.ReadFull(ctx.bc, ctx.dataBuf); err != nil {
+		if err == io.EOF {
+			return false, err
+		}
+		return false, fmt.Errorf("cannot read bool: %s", err)
+	}
+	v := ctx.dataBuf[0] != 0
+	return v, nil
+}
+
 func (ctx *vmselectRequestCtx) writeDataBufBytes() error {
 	if err := ctx.writeUint64(uint64(len(ctx.dataBuf))); err != nil {
 		return fmt.Errorf("cannot write data size: %s", err)
@@ -443,7 +455,7 @@ func (s *Server) processVMSelectRequest(ctx *vmselectRequestCtx) error {
 	}()
 
 	switch string(ctx.dataBuf) {
-	case "search_v2":
+	case "search_v3":
 		return s.processVMSelectSearchQuery(ctx)
 	case "labelValues":
 		return s.processVMSelectLabelValues(ctx)
@@ -714,6 +726,10 @@ func (s *Server) processVMSelectSearchQuery(ctx *vmselectRequestCtx) error {
 	if len(tail) > 0 {
 		return fmt.Errorf("unexpected non-zero tail left after unmarshaling SearchQuery: (len=%d) %q", len(tail), tail)
 	}
+	fetchData, err := ctx.readBool()
+	if err != nil {
+		return fmt.Errorf("cannot read `fetchData` bool: %s", err)
+	}
 
 	// Setup search.
 	if err := ctx.setupTfss(); err != nil {
@@ -728,7 +744,7 @@ func (s *Server) processVMSelectSearchQuery(ctx *vmselectRequestCtx) error {
 		MinTimestamp: ctx.sq.MinTimestamp,
 		MaxTimestamp: ctx.sq.MaxTimestamp,
 	}
-	ctx.sr.Init(s.storage, ctx.tfss, tr, *maxMetricsPerSearch)
+	ctx.sr.Init(s.storage, ctx.tfss, tr, fetchData, *maxMetricsPerSearch)
 	defer ctx.sr.MustClose()
 	if err := ctx.sr.Error(); err != nil {
 		// Send the error message to vmselect.

lib/storage/part_search.go

@@ -28,6 +28,9 @@ type partSearch struct {
 	// tr is a time range to search.
 	tr TimeRange
 
+	// Skip populating timestampsData and valuesData in Block if fetchData=false.
+	fetchData bool
+
 	metaindex []metaindexRow
 
 	ibCache *indexBlockCache
@@ -61,7 +64,7 @@ func (ps *partSearch) reset() {
 }
 
 // Init initializes the ps with the given p, tsids and tr.
-func (ps *partSearch) Init(p *part, tsids []TSID, tr TimeRange) {
+func (ps *partSearch) Init(p *part, tsids []TSID, tr TimeRange, fetchData bool) {
 	ps.reset()
 	ps.p = p
 
@@ -72,6 +75,7 @@ func (ps *partSearch) Init(p *part, tsids []TSID, tr TimeRange) {
 		ps.tsids = append(ps.tsids[:0], tsids...)
 	}
 	ps.tr = tr
+	ps.fetchData = fetchData
 	ps.metaindex = p.metaindex
 	ps.ibCache = &p.ibCache
 
@@ -281,11 +285,14 @@ func (ps *partSearch) searchBHS() bool {
 
 func (ps *partSearch) readBlock(bh *blockHeader) {
 	ps.Block.Reset()
+	ps.Block.bh = *bh
+	if !ps.fetchData {
+		return
+	}
+
 	ps.Block.timestampsData = bytesutil.Resize(ps.Block.timestampsData[:0], int(bh.TimestampsBlockSize))
 	ps.p.timestampsFile.ReadAt(ps.Block.timestampsData, int64(bh.TimestampsBlockOffset))
 
 	ps.Block.valuesData = bytesutil.Resize(ps.Block.valuesData[:0], int(bh.ValuesBlockSize))
 	ps.p.valuesFile.ReadAt(ps.Block.valuesData, int64(bh.ValuesBlockOffset))
-
-	ps.Block.bh = *bh
 }

lib/storage/part_search_test.go

@@ -1247,7 +1247,7 @@ func testPartSearch(t *testing.T, p *part, tsids []TSID, tr TimeRange, expectedR
 
 func testPartSearchSerial(p *part, tsids []TSID, tr TimeRange, expectedRawBlocks []rawBlock) error {
 	var ps partSearch
-	ps.Init(p, tsids, tr)
+	ps.Init(p, tsids, tr, true)
 	var bs []Block
 	for ps.NextBlock() {
 		var b Block

lib/storage/partition_search.go

@@ -56,7 +56,7 @@ func (pts *partitionSearch) reset() {
 // Init initializes the search in the given partition for the given tsid and tr.
 //
 // MustClose must be called when partition search is done.
-func (pts *partitionSearch) Init(pt *partition, tsids []TSID, tr TimeRange) {
+func (pts *partitionSearch) Init(pt *partition, tsids []TSID, tr TimeRange, fetchData bool) {
 	if pts.needClosing {
 		logger.Panicf("BUG: missing partitionSearch.MustClose call before the next call to Init")
 	}
@@ -85,7 +85,7 @@ func (pts *partitionSearch) Init(pt *partition, tsids []TSID, tr TimeRange) {
 	}
 	pts.psPool = pts.psPool[:len(pts.pws)]
 	for i, pw := range pts.pws {
-		pts.psPool[i].Init(pw.p, tsids, tr)
+		pts.psPool[i].Init(pw.p, tsids, tr, fetchData)
 	}
 
 	// Initialize the psHeap.

lib/storage/partition_search_test.go

@@ -238,7 +238,7 @@ func testPartitionSearchSerial(pt *partition, tsids []TSID, tr TimeRange, rbsExp
 
 	bs := []Block{}
 	var pts partitionSearch
-	pts.Init(pt, tsids, tr)
+	pts.Init(pt, tsids, tr, true)
 	for pts.NextBlock() {
 		var b Block
 		b.CopyFrom(pts.Block)
@@ -263,7 +263,7 @@ func testPartitionSearchSerial(pt *partition, tsids []TSID, tr TimeRange, rbsExp
 	}
 
 	// verify that empty tsids returns empty result
-	pts.Init(pt, []TSID{}, tr)
+	pts.Init(pt, []TSID{}, tr, true)
 	if pts.NextBlock() {
 		return fmt.Errorf("unexpected block got for an empty tsids list: %+v", pts.Block)
 	}
@@ -271,6 +271,16 @@ func testPartitionSearchSerial(pt *partition, tsids []TSID, tr TimeRange, rbsExp
 		return fmt.Errorf("unexpected error on empty tsids list: %s", err)
 	}
 	pts.MustClose()
+
+	pts.Init(pt, []TSID{}, tr, false)
+	if pts.NextBlock() {
+		return fmt.Errorf("unexpected block got for an empty tsids list: %+v", pts.Block)
+	}
+	if err := pts.Error(); err != nil {
+		return fmt.Errorf("unexpected error on empty tsids list: %s", err)
+	}
+	pts.MustClose()
+
 	return nil
 }
 

lib/storage/search.go

@@ -110,7 +110,7 @@ func (s *Search) reset() {
 // Init initializes s from the given storage, tfss and tr.
 //
 // MustClose must be called when the search is done.
-func (s *Search) Init(storage *Storage, tfss []*TagFilters, tr TimeRange, maxMetrics int) {
+func (s *Search) Init(storage *Storage, tfss []*TagFilters, tr TimeRange, fetchData bool, maxMetrics int) {
 	if s.needClosing {
 		logger.Panicf("BUG: missing MustClose call before the next call to Init")
 	}
@@ -123,7 +123,7 @@ func (s *Search) Init(storage *Storage, tfss []*TagFilters, tr TimeRange, maxMet
 	// It is ok to call Init on error from storage.searchTSIDs.
 	// Init must be called before returning because it will fail
 	// on Seach.MustClose otherwise.
-	s.ts.Init(storage.tb, tsids, tr)
+	s.ts.Init(storage.tb, tsids, tr, fetchData)
 
 	if err != nil {
 		s.err = err

lib/storage/search_test.go

@@ -200,7 +200,7 @@ func testSearch(st *Storage, tr TimeRange, mrs []MetricRow, accountsCount int) e
 		}
 
 		// Search
-		s.Init(st, []*TagFilters{tfs}, tr, 1e5)
+		s.Init(st, []*TagFilters{tfs}, tr, true, 1e5)
 		var mbs []MetricBlock
 		for s.NextMetricBlock() {
 			var b Block

lib/storage/storage_test.go

@@ -506,12 +506,24 @@ func testStorageDeleteMetrics(s *Storage, workerNum int) error {
 		MaxTimestamp: 2e10,
 	}
 	metricBlocksCount := func(tfs *TagFilters) int {
+		// Verify the number of blocks with fetchData=true
 		n := 0
-		sr.Init(s, []*TagFilters{tfs}, tr, 1e5)
+		sr.Init(s, []*TagFilters{tfs}, tr, true, 1e5)
 		for sr.NextMetricBlock() {
 			n++
 		}
 		sr.MustClose()
+
+		// Make sure the number of blocks with fetchData=false is the same.
+		m := 0
+		sr.Init(s, []*TagFilters{tfs}, tr, false, 1e5)
+		for sr.NextMetricBlock() {
+			m++
+		}
+		sr.MustClose()
+		if n != m {
+			return -1
+		}
 		return n
 	}
 	for i := 0; i < metricsCount; i++ {

lib/storage/table_search.go

@@ -55,7 +55,7 @@ func (ts *tableSearch) reset() {
 // Init initializes the ts.
 //
 // MustClose must be called then the tableSearch is done.
-func (ts *tableSearch) Init(tb *table, tsids []TSID, tr TimeRange) {
+func (ts *tableSearch) Init(tb *table, tsids []TSID, tr TimeRange, fetchData bool) {
 	if ts.needClosing {
 		logger.Panicf("BUG: missing MustClose call before the next call to Init")
 	}
@@ -86,7 +86,7 @@ func (ts *tableSearch) Init(tb *table, tsids []TSID, tr TimeRange) {
 	}
 	ts.ptsPool = ts.ptsPool[:len(ts.ptws)]
 	for i, ptw := range ts.ptws {
-		ts.ptsPool[i].Init(ptw.pt, tsids, tr)
+		ts.ptsPool[i].Init(ptw.pt, tsids, tr, fetchData)
 	}
 
 	// Initialize the ptsHeap.

lib/storage/table_search_test.go

@@ -251,7 +251,7 @@ func testTableSearchSerial(tb *table, tsids []TSID, tr TimeRange, rbsExpected []
 
 	bs := []Block{}
 	var ts tableSearch
-	ts.Init(tb, tsids, tr)
+	ts.Init(tb, tsids, tr, true)
 	for ts.NextBlock() {
 		var b Block
 		b.CopyFrom(ts.Block)
@@ -276,7 +276,7 @@ func testTableSearchSerial(tb *table, tsids []TSID, tr TimeRange, rbsExpected []
 	}
 
 	// verify that empty tsids returns empty result
-	ts.Init(tb, []TSID{}, tr)
+	ts.Init(tb, []TSID{}, tr, true)
 	if ts.NextBlock() {
 		return fmt.Errorf("unexpected block got for an empty tsids list: %+v", ts.Block)
 	}
@@ -284,5 +284,15 @@ func testTableSearchSerial(tb *table, tsids []TSID, tr TimeRange, rbsExpected []
 		return fmt.Errorf("unexpected error on empty tsids list: %s", err)
 	}
 	ts.MustClose()
+
+	ts.Init(tb, []TSID{}, tr, false)
+	if ts.NextBlock() {
+		return fmt.Errorf("unexpected block got for an empty tsids list with fetchData=false: %+v", ts.Block)
+	}
+	if err := ts.Error(); err != nil {
+		return fmt.Errorf("unexpected error on empty tsids list with fetchData=false: %s", err)
+	}
+	ts.MustClose()
+
 	return nil
 }

lib/storage/table_search_timing_test.go

@@ -26,7 +26,11 @@ func BenchmarkTableSearch(b *testing.B) {
 				b.Run(fmt.Sprintf("tsidsCount_%d", tsidsCount), func(b *testing.B) {
 					for _, tsidsSearch := range []int{1, 1e1, 1e2, 1e3, 1e4} {
 						b.Run(fmt.Sprintf("tsidsSearch_%d", tsidsSearch), func(b *testing.B) {
-							benchmarkTableSearch(b, rowsCount, tsidsCount, tsidsSearch)
+							for _, fetchData := range []bool{true, false} {
+								b.Run(fmt.Sprintf("fetchData_%v", fetchData), func(b *testing.B) {
+									benchmarkTableSearch(b, rowsCount, tsidsCount, tsidsSearch, fetchData)
+								})
+							}
 						})
 					}
 				})
@@ -103,9 +107,9 @@ func createBenchTable(b *testing.B, path string, startTimestamp int64, rowsPerIn
 	tb.MustClose()
 }
 
-func benchmarkTableSearch(b *testing.B, rowsCount, tsidsCount, tsidsSearch int) {
+func benchmarkTableSearch(b *testing.B, rowsCount, tsidsCount, tsidsSearch int, fetchData bool) {
 	startTimestamp := timestampFromTime(time.Now()) - 365*24*3600*1000
-	rowsPerInsert := int(maxRawRowsPerPartition)
+	rowsPerInsert := getMaxRawRowsPerPartition()
 
 	tb := openBenchTable(b, startTimestamp, rowsPerInsert, rowsCount, tsidsCount)
 	tr := TimeRange{
@@ -127,7 +131,7 @@ func benchmarkTableSearch(b *testing.B, rowsCount, tsidsCount, tsidsSearch int)
 			for i := range tsids {
 				tsids[i].MetricID = 1 + uint64(i)
 			}
-			ts.Init(tb, tsids, tr)
+			ts.Init(tb, tsids, tr, fetchData)
 			for ts.NextBlock() {
 			}
 			ts.MustClose()