timescale · JamesGuthrie · Aug 18, 2022 · Aug 16, 2022
@@ -23,6 +23,7 @@ We use the following categories for changes:
 
 ### Fixed
 - Make Jaeger Event queryable using name and tags [#1553]
+- Reset inverted labels cache on epoch change [#1561]
 
 ## [0.13.0] - 2022-07-20
 

@@ -15,7 +15,7 @@ TODO (@ante do you want to write this?)
 
 ## Write Path
 
-A `WriteRequest` is made out of a `[]TimeSeries` each of which contains a set of lables, each a `{string, string}`, and a set of samples, each a `{Timestamp, Value}`. Logically, the write path deals with this write request multiple stages. In Go notation, this can be thought of as follows
+A `WriteRequest` is made out of a `[]TimeSeries` each of which contains a set of labels, each a `{string, string}`, and a set of samples, each a `{Timestamp, Value}`. Logically, the write path deals with this write request multiple stages. In Go notation, this can be thought of as follows
 
 ```go
 type WriteRequest = []TimeSeries

@@ -42,7 +42,7 @@ type InvertedLabelsCache struct {
 }
 
 // Cache is thread-safe
-func NewInvertedLablesCache(size uint64) (*InvertedLabelsCache, error) {
+func NewInvertedLabelsCache(size uint64) (*InvertedLabelsCache, error) {
 	if size <= 0 {
 		return nil, fmt.Errorf("labels cache size must be > 0")
 	}
@@ -62,3 +62,7 @@ func (c *InvertedLabelsCache) Put(key LabelKey, val LabelInfo) bool {
 	_, added := c.cache.Insert(key, val, uint64(key.len())+uint64(val.len())+17)
 	return added
 }
+
+func (c *InvertedLabelsCache) Reset() {
+	c.cache.Reset()
+}
@@ -38,6 +38,7 @@ type pgxDispatcher struct {
 	conn                   pgxconn.PgxConn
 	metricTableNames       cache.MetricCache
 	scache                 cache.SeriesCache
+	invertedLabelsCache    *cache.InvertedLabelsCache
 	exemplarKeyPosCache    cache.PositionCache
 	batchers               sync.Map
 	completeMetricCreation chan struct{}
@@ -76,7 +77,7 @@ func newPgxDispatcher(conn pgxconn.PgxConn, mCache cache.MetricCache, scache cac
 	}
 
 	labelArrayOID := model.GetCustomTypeOID(model.LabelArray)
-	labelsCache, err := cache.NewInvertedLablesCache(cfg.InvertedLabelsCacheSize)
+	labelsCache, err := cache.NewInvertedLabelsCache(cfg.InvertedLabelsCacheSize)
 	if err != nil {
 		return nil, err
 	}
@@ -91,6 +92,7 @@ func newPgxDispatcher(conn pgxconn.PgxConn, mCache cache.MetricCache, scache cac
 		conn:                   conn,
 		metricTableNames:       mCache,
 		scache:                 scache,
+		invertedLabelsCache:    labelsCache,
 		exemplarKeyPosCache:    eCache,
 		completeMetricCreation: make(chan struct{}, 1),
 		asyncAcks:              cfg.AsyncAcks,
@@ -156,10 +158,14 @@ func (p *pgxDispatcher) refreshSeriesEpoch(existingEpoch model.SeriesEpoch) (mod
 	if err != nil {
 		// Trash the cache just in case an epoch change occurred, seems safer
 		p.scache.Reset()
+		// Also trash the inverted labels cache, which can also be invalidated when the series cache is
+		p.invertedLabelsCache.Reset()
 		return model.InvalidSeriesEpoch, err
 	}
 	if existingEpoch == model.InvalidSeriesEpoch || dbEpoch != existingEpoch {
 		p.scache.Reset()
+		// If the series cache needs to be invalidated, so does the inverted labels cache
+		p.invertedLabelsCache.Reset()
 	}
 	return dbEpoch, nil
 }

@@ -276,7 +276,7 @@ func TestPGXInserterInsertSeries(t *testing.T) {
 			mock := model.NewSqlRecorder(c.sqlQueries, t)
 			scache := cache.NewSeriesCache(cache.DefaultConfig, nil)
 			scache.Reset()
-			lCache, _ := cache.NewInvertedLablesCache(10)
+			lCache, _ := cache.NewInvertedLabelsCache(10)
 			sw := NewSeriesWriter(mock, 0, lCache)
 
 			lsi := make([]model.Insertable, 0)
@@ -393,6 +393,21 @@ func TestPGXInserterCacheReset(t *testing.T) {
 		},
 		{Sql: "COMMIT;"},
 		{Sql: "BEGIN;"},
+		{
+			Sql: "SELECT * FROM _prom_catalog.get_or_create_label_ids($1, $2, $3, $4)",
+			Args: []interface{}{
+				"metric_1",
+				tableName,
+				[]string{"__name__", "name_1", "name_1"},
+				[]string{"metric_1", "value_1", "value_2"},
+			},
+			Results: model.RowResults{
+				{[]int32{1, 2, 2}, []int32{1, 2, 3}, []string{"__name__", "name_1", "name_1"}, []string{"metric_1", "value_1", "value_2"}},
+			},
+			Err: error(nil),
+		},
+		{Sql: "COMMIT;"},
+		{Sql: "BEGIN;"},
 		{
 			Sql: seriesInsertSQL,
 			Args: []interface{}{
@@ -419,11 +434,12 @@ func TestPGXInserterCacheReset(t *testing.T) {
 
 	mock := model.NewSqlRecorder(sqlQueries, t)
 	scache := cache.NewSeriesCache(cache.DefaultConfig, nil)
-	lcache, _ := cache.NewInvertedLablesCache(10)
+	lcache, _ := cache.NewInvertedLabelsCache(10)
 	sw := NewSeriesWriter(mock, 0, lcache)
 	inserter := pgxDispatcher{
-		conn:   mock,
-		scache: scache,
+		conn:                mock,
+		scache:              scache,
+		invertedLabelsCache: lcache,
 	}
 
 	makeSamples := func(series []labels.Labels) []model.Insertable {
@@ -460,7 +476,7 @@ func TestPGXInserterCacheReset(t *testing.T) {
 		}
 	}
 
-	// refreshing during the same epoch givesthe same IDs without checking the DB
+	// refreshing during the same epoch gives the same IDs without checking the DB
 	_, err = inserter.refreshSeriesEpoch(1)
 	require.NoError(t, err)