chore: Fix regression in bloom gateway that caused nothing to be filtered (#14807)

Pull request #14661 added the series labels to the `FilterChunkRefs` request in order to be able to filter out full series that do not contain the filter key when using bloom filters.

However, this change incorrectly assumed that `Chunk.Metric` from the `GetChunks()` call contains the labels of the stream. This information is only populated once the chunk is fetched, though. Therefore the list of labels was empty, and no chunk refs were filtered.

Signed-off-by: Christian Haudum <[email protected]>
(cherry picked from commit 3b20cb0)

Author: chaudum

pkg/indexgateway/gateway.go

@@ -209,6 +209,8 @@ func buildResponses(query seriesindex.Query, batch seriesindex.ReadBatchResult,
 
 func (g *Gateway) GetChunkRef(ctx context.Context, req *logproto.GetChunkRefRequest) (result *logproto.GetChunkRefResponse, err error) {
 	logger := util_log.WithContext(ctx, g.log)
+	sp, ctx := opentracing.StartSpanFromContext(ctx, "indexgateway.GetChunkRef")
+	defer sp.Finish()
 
 	instanceID, err := tenant.TenantID(ctx)
 	if err != nil {
@@ -225,16 +227,12 @@ func (g *Gateway) GetChunkRef(ctx context.Context, req *logproto.GetChunkRefRequ
 		return nil, err
 	}
 
-	series := make(map[uint64]labels.Labels)
 	result = &logproto.GetChunkRefResponse{
 		Refs: make([]*logproto.ChunkRef, 0, len(chunks)),
 	}
 	for _, cs := range chunks {
 		for i := range cs {
 			result.Refs = append(result.Refs, &cs[i].ChunkRef)
-			if _, ok := series[cs[i].Fingerprint]; !ok {
-				series[cs[i].Fingerprint] = cs[i].Metric
-			}
 		}
 	}
 
@@ -261,10 +259,22 @@ func (g *Gateway) GetChunkRef(ctx context.Context, req *logproto.GetChunkRefRequ
 		return result, nil
 	}
 
-	chunkRefs, used, err := g.bloomQuerier.FilterChunkRefs(ctx, instanceID, req.From, req.Through, series, result.Refs, req.Plan)
+	// Doing a "duplicate" index lookup is not ideal,
+	// however, modifying the GetChunkRef() response, which contains the logproto.ChunkRef is neither.
+	start := time.Now()
+	series, err := g.indexQuerier.GetSeries(ctx, instanceID, req.From, req.Through, matchers...)
+	seriesMap := make(map[uint64]labels.Labels, len(series))
+	for _, s := range series {
+		seriesMap[s.Hash()] = s
+	}
+	sp.LogKV("msg", "indexQuerier.GetSeries", "duration", time.Since(start), "count", len(series))
+
+	start = time.Now()
+	chunkRefs, used, err := g.bloomQuerier.FilterChunkRefs(ctx, instanceID, req.From, req.Through, seriesMap, result.Refs, req.Plan)
 	if err != nil {
 		return nil, err
 	}
+	sp.LogKV("msg", "bloomQuerier.FilterChunkRefs", "duration", time.Since(start))
 
 	result.Refs = chunkRefs
 	level.Info(logger).Log("msg", "return filtered chunk refs", "unfiltered", initialChunkCount, "filtered", len(result.Refs), "used_blooms", used)