feat(blooms): Add series & chunks per block metrics (#13721)

pkg/storage/bloom/v1/builder.go

@@ -217,6 +217,7 @@ func (mb *MergeBuilder) processNextSeries(
 ) (
 	*SeriesWithBlooms, // nextInBlocks pointer update
 	int, // bytes added
+	int, // chunks added
 	bool, // blocksFinished update
 	bool, // done building block
 	error, // error
@@ -230,7 +231,7 @@ func (mb *MergeBuilder) processNextSeries(
 	}()
 
 	if !mb.store.Next() {
-		return nil, 0, false, true, nil
+		return nil, 0, 0, false, true, nil
 	}
 
 	nextInStore := mb.store.At()
@@ -249,7 +250,7 @@ func (mb *MergeBuilder) processNextSeries(
 		}
 
 		if err := mb.blocks.Err(); err != nil {
-			return nil, 0, false, false, errors.Wrap(err, "iterating blocks")
+			return nil, 0, 0, false, false, errors.Wrap(err, "iterating blocks")
 		}
 		blockSeriesIterated++
 		nextInBlocks = mb.blocks.At()
@@ -276,11 +277,11 @@ func (mb *MergeBuilder) processNextSeries(
 
 	for bloom := range ch {
 		if bloom.Err != nil {
-			return nil, bytesAdded, false, false, errors.Wrap(bloom.Err, "populating bloom")
+			return nil, bytesAdded, 0, false, false, errors.Wrap(bloom.Err, "populating bloom")
 		}
 		offset, err := builder.AddBloom(bloom.Bloom)
 		if err != nil {
-			return nil, bytesAdded, false, false, errors.Wrapf(
+			return nil, bytesAdded, 0, false, false, errors.Wrapf(
 				err, "adding bloom to block for fp (%s)", nextInStore.Fingerprint,
 			)
 		}
@@ -290,25 +291,29 @@ func (mb *MergeBuilder) processNextSeries(
 
 	done, err := builder.AddSeries(*nextInStore, offsets)
 	if err != nil {
-		return nil, bytesAdded, false, false, errors.Wrap(err, "committing series")
+		return nil, bytesAdded, 0, false, false, errors.Wrap(err, "committing series")
 	}
 
-	return nextInBlocks, bytesAdded, blocksFinished, done, nil
+	return nextInBlocks, bytesAdded, chunksIndexed + chunksCopied, blocksFinished, done, nil
 }
 
 func (mb *MergeBuilder) Build(builder *BlockBuilder) (checksum uint32, totalBytes int, err error) {
 	var (
-		nextInBlocks   *SeriesWithBlooms
-		blocksFinished bool // whether any previous blocks have been exhausted while building new block
-		done           bool
+		nextInBlocks     *SeriesWithBlooms
+		blocksFinished   bool // whether any previous blocks have been exhausted while building new block
+		done             bool
+		totalSeriesAdded = 0
+		totalChunksAdded int
 	)
 	for {
-		var bytesAdded int
-		nextInBlocks, bytesAdded, blocksFinished, done, err = mb.processNextSeries(builder, nextInBlocks, blocksFinished)
+		var bytesAdded, chunksAdded int
+		nextInBlocks, bytesAdded, chunksAdded, blocksFinished, done, err = mb.processNextSeries(builder, nextInBlocks, blocksFinished)
 		totalBytes += bytesAdded
+		totalChunksAdded += chunksAdded
 		if err != nil {
 			return 0, totalBytes, errors.Wrap(err, "processing next series")
 		}
+		totalSeriesAdded++
 		if done {
 			break
 		}
@@ -324,6 +329,8 @@ func (mb *MergeBuilder) Build(builder *BlockBuilder) (checksum uint32, totalByte
 		flushedFor = blockFlushReasonFull
 	}
 	mb.metrics.blockSize.Observe(float64(sz))
+	mb.metrics.seriesPerBlock.Observe(float64(totalSeriesAdded))
+	mb.metrics.chunksPerBlock.Observe(float64(totalChunksAdded))
 	mb.metrics.blockFlushReason.WithLabelValues(flushedFor).Inc()
 
 	checksum, err = builder.Close()

pkg/storage/bloom/v1/metrics.go

@@ -20,6 +20,8 @@ type Metrics struct {
 	insertsTotal        *prometheus.CounterVec
 	sourceBytesAdded    prometheus.Counter
 	blockSize           prometheus.Histogram
+	seriesPerBlock      prometheus.Histogram
+	chunksPerBlock      prometheus.Histogram
 	blockFlushReason    *prometheus.CounterVec
 
 	// reads
@@ -120,6 +122,18 @@ func NewMetrics(r prometheus.Registerer) *Metrics {
 			Help:      "Size of the bloom block in bytes",
 			Buckets:   prometheus.ExponentialBucketsRange(1<<20, 1<<30, 8),
 		}),
+		seriesPerBlock: promauto.With(r).NewHistogram(prometheus.HistogramOpts{
+			Namespace: constants.Loki,
+			Name:      "bloom_series_per_block",
+			Help:      "Number of series per block",
+			Buckets:   prometheus.ExponentialBuckets(1, 2, 9), // 2 --> 256
+		}),
+		chunksPerBlock: promauto.With(r).NewHistogram(prometheus.HistogramOpts{
+			Namespace: constants.Loki,
+			Name:      "bloom_chunks_per_block",
+			Help:      "Number of chunks per block",
+			Buckets:   prometheus.ExponentialBuckets(1, 2, 15), // 2 --> 16384
+		}),
 		blockFlushReason: promauto.With(r).NewCounterVec(prometheus.CounterOpts{
 			Namespace: constants.Loki,
 			Name:      "bloom_block_flush_reason_total",