lib/storage: reset MetricName->TSID cache after marking metricIDs as deleted

This is a follow-up commit after 12b16077c4 ,
which didn't reset the `tsidCache` in all the required places.
This could result in indefinite errors like:

    missing metricName by metricID ...; this could be the case after unclean shutdown; deleting the metricID, so it could be re-created next time

Fix this by resetting the cache inside deleteMetricIDs function.

lib/storage/index_db.go

@@ -128,6 +128,9 @@ type indexDB struct {
 	// Cache for fast MetricID -> MetricName lookup.
 	metricNameCache *workingsetcache.Cache
 
+	// Cache for fast MetricName -> TSID lookups.
+	tsidCache *workingsetcache.Cache
+
 	// Cache for useless TagFilters entries, which have no tag filters
 	// matching low number of metrics.
 	uselessTagFiltersCache *workingsetcache.Cache
@@ -155,13 +158,16 @@ type indexDB struct {
 }
 
 // openIndexDB opens index db from the given path with the given caches.
-func openIndexDB(path string, metricIDCache, metricNameCache *workingsetcache.Cache, currHourMetricIDs, prevHourMetricIDs *atomic.Value) (*indexDB, error) {
+func openIndexDB(path string, metricIDCache, metricNameCache, tsidCache *workingsetcache.Cache, currHourMetricIDs, prevHourMetricIDs *atomic.Value) (*indexDB, error) {
 	if metricIDCache == nil {
 		logger.Panicf("BUG: metricIDCache must be non-nil")
 	}
 	if metricNameCache == nil {
 		logger.Panicf("BUG: metricNameCache must be non-nil")
 	}
+	if tsidCache == nil {
+		logger.Panicf("BUG: tsidCache must be nin-nil")
+	}
 	if currHourMetricIDs == nil {
 		logger.Panicf("BUG: currHourMetricIDs must be non-nil")
 	}
@@ -187,6 +193,7 @@ func openIndexDB(path string, metricIDCache, metricNameCache *workingsetcache.Ca
 		tagCache:                       workingsetcache.New(mem/32, time.Hour),
 		metricIDCache:                  metricIDCache,
 		metricNameCache:                metricNameCache,
+		tsidCache:                      tsidCache,
 		uselessTagFiltersCache:         workingsetcache.New(mem/128, time.Hour),
 		metricIDsPerDateTagFilterCache: workingsetcache.New(mem/128, time.Hour),
 
@@ -360,6 +367,7 @@ func (db *indexDB) decRef() {
 	db.tagCache = nil
 	db.metricIDCache = nil
 	db.metricNameCache = nil
+	db.tsidCache = nil
 	db.uselessTagFiltersCache = nil
 	db.metricIDsPerDateTagFilterCache = nil
 
@@ -1233,6 +1241,9 @@ func (db *indexDB) deleteMetricIDs(metricIDs []uint64) error {
 	// Reset TagFilters -> TSIDS cache, since it may contain deleted TSIDs.
 	invalidateTagCache()
 
+	// Reset MetricName -> TSID cache, since it may contain deleted TSIDs.
+	db.tsidCache.Reset()
+
 	// Do not reset uselessTagFiltersCache, since the found metricIDs
 	// on cache miss are filtered out later with deletedMetricIDs.
 	return nil
@@ -1515,7 +1526,7 @@ func (is *indexSearch) searchTSIDs(tfss []*TagFilters, tr TimeRange, maxMetrics
 	tsids := make([]TSID, len(metricIDs))
 	i := 0
 	for _, metricID := range metricIDs {
-		// Try obtaining TSIDs from db.tsidCache. This is much faster
+		// Try obtaining TSIDs from MetricID->TSID cache. This is much faster
 		// than scanning the mergeset if it contains a lot of metricIDs.
 		tsid := &tsids[i]
 		err := is.db.getFromMetricIDCache(tsid, metricID)

lib/storage/index_db_test.go

@@ -466,8 +466,10 @@ func TestMarshalUnmarshalTSIDs(t *testing.T) {
 func TestIndexDBOpenClose(t *testing.T) {
 	metricIDCache := workingsetcache.New(1234, time.Hour)
 	metricNameCache := workingsetcache.New(1234, time.Hour)
+	tsidCache := workingsetcache.New(1234, time.Hour)
 	defer metricIDCache.Stop()
 	defer metricNameCache.Stop()
+	defer tsidCache.Stop()
 
 	var hmCurr atomic.Value
 	hmCurr.Store(&hourMetricIDs{})
@@ -475,7 +477,7 @@ func TestIndexDBOpenClose(t *testing.T) {
 	hmPrev.Store(&hourMetricIDs{})
 
 	for i := 0; i < 5; i++ {
-		db, err := openIndexDB("test-index-db", metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+		db, err := openIndexDB("test-index-db", metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -494,8 +496,10 @@ func TestIndexDB(t *testing.T) {
 	t.Run("serial", func(t *testing.T) {
 		metricIDCache := workingsetcache.New(1234, time.Hour)
 		metricNameCache := workingsetcache.New(1234, time.Hour)
+		tsidCache := workingsetcache.New(1234, time.Hour)
 		defer metricIDCache.Stop()
 		defer metricNameCache.Stop()
+		defer tsidCache.Stop()
 
 		var hmCurr atomic.Value
 		hmCurr.Store(&hourMetricIDs{})
@@ -503,7 +507,7 @@ func TestIndexDB(t *testing.T) {
 		hmPrev.Store(&hourMetricIDs{})
 
 		dbName := "test-index-db-serial"
-		db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+		db, err := openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -533,7 +537,7 @@ func TestIndexDB(t *testing.T) {
 
 		// Re-open the db and verify it works as expected.
 		db.MustClose()
-		db, err = openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+		db, err = openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -551,8 +555,10 @@ func TestIndexDB(t *testing.T) {
 	t.Run("concurrent", func(t *testing.T) {
 		metricIDCache := workingsetcache.New(1234, time.Hour)
 		metricNameCache := workingsetcache.New(1234, time.Hour)
+		tsidCache := workingsetcache.New(1234, time.Hour)
 		defer metricIDCache.Stop()
 		defer metricNameCache.Stop()
+		defer tsidCache.Stop()
 
 		var hmCurr atomic.Value
 		hmCurr.Store(&hourMetricIDs{})
@@ -560,7 +566,7 @@ func TestIndexDB(t *testing.T) {
 		hmPrev.Store(&hourMetricIDs{})
 
 		dbName := "test-index-db-concurrent"
-		db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+		db, err := openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 		if err != nil {
 			t.Fatalf("cannot open indexDB: %s", err)
 		}
@@ -1532,8 +1538,10 @@ func TestMatchTagFilters(t *testing.T) {
 func TestSearchTSIDWithTimeRange(t *testing.T) {
 	metricIDCache := workingsetcache.New(1234, time.Hour)
 	metricNameCache := workingsetcache.New(1234, time.Hour)
+	tsidCache := workingsetcache.New(1234, time.Hour)
 	defer metricIDCache.Stop()
 	defer metricNameCache.Stop()
+	defer tsidCache.Stop()
 
 	currMetricIDs := &hourMetricIDs{
 		isFull: true,
@@ -1551,7 +1559,7 @@ func TestSearchTSIDWithTimeRange(t *testing.T) {
 	hmPrev.Store(prevMetricIDs)
 
 	dbName := "test-index-db-ts-range"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 	if err != nil {
 		t.Fatalf("cannot open indexDB: %s", err)
 	}

lib/storage/index_db_timing_test.go

@@ -45,8 +45,10 @@ func BenchmarkIndexDBAddTSIDs(b *testing.B) {
 
 	metricIDCache := workingsetcache.New(1234, time.Hour)
 	metricNameCache := workingsetcache.New(1234, time.Hour)
+	tsidCache := workingsetcache.New(1234, time.Hour)
 	defer metricIDCache.Stop()
 	defer metricNameCache.Stop()
+	defer tsidCache.Stop()
 
 	var hmCurr atomic.Value
 	hmCurr.Store(&hourMetricIDs{})
@@ -54,7 +56,7 @@ func BenchmarkIndexDBAddTSIDs(b *testing.B) {
 	hmPrev.Store(&hourMetricIDs{})
 
 	const dbName = "bench-index-db-add-tsids"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 	if err != nil {
 		b.Fatalf("cannot open indexDB: %s", err)
 	}
@@ -116,8 +118,10 @@ func BenchmarkHeadPostingForMatchers(b *testing.B) {
 	// See https://www.robustperception.io/evaluating-performance-and-correctness for more details.
 	metricIDCache := workingsetcache.New(1234, time.Hour)
 	metricNameCache := workingsetcache.New(1234, time.Hour)
+	tsidCache := workingsetcache.New(1234, time.Hour)
 	defer metricIDCache.Stop()
 	defer metricNameCache.Stop()
+	defer tsidCache.Stop()
 
 	var hmCurr atomic.Value
 	hmCurr.Store(&hourMetricIDs{})
@@ -125,7 +129,7 @@ func BenchmarkHeadPostingForMatchers(b *testing.B) {
 	hmPrev.Store(&hourMetricIDs{})
 
 	const dbName = "bench-head-posting-for-matchers"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 	if err != nil {
 		b.Fatalf("cannot open indexDB: %s", err)
 	}
@@ -302,8 +306,10 @@ func BenchmarkHeadPostingForMatchers(b *testing.B) {
 func BenchmarkIndexDBGetTSIDs(b *testing.B) {
 	metricIDCache := workingsetcache.New(1234, time.Hour)
 	metricNameCache := workingsetcache.New(1234, time.Hour)
+	tsidCache := workingsetcache.New(1234, time.Hour)
 	defer metricIDCache.Stop()
 	defer metricNameCache.Stop()
+	defer tsidCache.Stop()
 
 	var hmCurr atomic.Value
 	hmCurr.Store(&hourMetricIDs{})
@@ -311,7 +317,7 @@ func BenchmarkIndexDBGetTSIDs(b *testing.B) {
 	hmPrev.Store(&hourMetricIDs{})
 
 	const dbName = "bench-index-db-get-tsids"
-	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, &hmCurr, &hmPrev)
+	db, err := openIndexDB(dbName, metricIDCache, metricNameCache, tsidCache, &hmCurr, &hmPrev)
 	if err != nil {
 		b.Fatalf("cannot open indexDB: %s", err)
 	}

lib/storage/storage.go

@@ -176,7 +176,7 @@ func OpenStorage(path string, retentionMonths int) (*Storage, error) {
 	if err := fs.MkdirAllIfNotExist(idbSnapshotsPath); err != nil {
 		return nil, fmt.Errorf("cannot create %q: %w", idbSnapshotsPath, err)
 	}
-	idbCurr, idbPrev, err := openIndexDBTables(idbPath, s.metricIDCache, s.metricNameCache, &s.currHourMetricIDs, &s.prevHourMetricIDs)
+	idbCurr, idbPrev, err := openIndexDBTables(idbPath, s.metricIDCache, s.metricNameCache, s.tsidCache, &s.currHourMetricIDs, &s.prevHourMetricIDs)
 	if err != nil {
 		return nil, fmt.Errorf("cannot open indexdb tables at %q: %w", idbPath, err)
 	}
@@ -552,7 +552,7 @@ func (s *Storage) mustRotateIndexDB() {
 	// Create new indexdb table.
 	newTableName := nextIndexDBTableName()
 	idbNewPath := s.path + "/indexdb/" + newTableName
-	idbNew, err := openIndexDB(idbNewPath, s.metricIDCache, s.metricNameCache, &s.currHourMetricIDs, &s.prevHourMetricIDs)
+	idbNew, err := openIndexDB(idbNewPath, s.metricIDCache, s.metricNameCache, s.tsidCache, &s.currHourMetricIDs, &s.prevHourMetricIDs)
 	if err != nil {
 		logger.Panicf("FATAL: cannot create new indexDB at %q: %s", idbNewPath, err)
 	}
@@ -942,11 +942,10 @@ func (s *Storage) DeleteMetrics(tfss []*TagFilters) (int, error) {
 	if err != nil {
 		return deletedCount, fmt.Errorf("cannot delete tsids: %w", err)
 	}
-	// Reset MetricName->TSID cache in order to prevent from adding new data points
+	// Do not reset MetricName->TSID cache in order to prevent from adding new data points
-	// to deleted time series in Storage.add.
+	// to deleted time series in Storage.add, since it is already reset inside DeleteTSIDs.
-	s.tsidCache.Reset()
 
-	// Do not reset MetricID -> MetricName cache, since it must be used only
+	// Do not reset MetricID->MetricName cache, since it must be used only
 	// after filtering out deleted metricIDs.
 
 	return deletedCount, nil
@@ -1730,7 +1729,8 @@ func (s *Storage) putTSIDToCache(tsid *TSID, metricName []byte) {
 	s.tsidCache.Set(metricName, buf)
 }
 
-func openIndexDBTables(path string, metricIDCache, metricNameCache *workingsetcache.Cache, currHourMetricIDs, prevHourMetricIDs *atomic.Value) (curr, prev *indexDB, err error) {
+func openIndexDBTables(path string, metricIDCache, metricNameCache, tsidCache *workingsetcache.Cache,
+	currHourMetricIDs, prevHourMetricIDs *atomic.Value) (curr, prev *indexDB, err error) {
 	if err := fs.MkdirAllIfNotExist(path); err != nil {
 		return nil, nil, fmt.Errorf("cannot create directory %q: %w", path, err)
 	}
@@ -1789,12 +1789,12 @@ func openIndexDBTables(path string, metricIDCache, metricNameCache *workingsetca
 	// Open the last two tables.
 	currPath := path + "/" + tableNames[len(tableNames)-1]
 
-	curr, err = openIndexDB(currPath, metricIDCache, metricNameCache, currHourMetricIDs, prevHourMetricIDs)
+	curr, err = openIndexDB(currPath, metricIDCache, metricNameCache, tsidCache, currHourMetricIDs, prevHourMetricIDs)
 	if err != nil {
 		return nil, nil, fmt.Errorf("cannot open curr indexdb table at %q: %w", currPath, err)
 	}
 	prevPath := path + "/" + tableNames[len(tableNames)-2]
-	prev, err = openIndexDB(prevPath, metricIDCache, metricNameCache, currHourMetricIDs, prevHourMetricIDs)
+	prev, err = openIndexDB(prevPath, metricIDCache, metricNameCache, tsidCache, currHourMetricIDs, prevHourMetricIDs)
 	if err != nil {
 		curr.MustClose()
 		return nil, nil, fmt.Errorf("cannot open prev indexdb table at %q: %w", prevPath, err)