From c263a681f8e19417ea3056a3e2cae7d3015d081a Mon Sep 17 00:00:00 2001
From: Salva Corts <salva.corts@grafana.com>
Date: Fri, 12 Jul 2024 10:11:14 +0200
Subject: [PATCH] fix: add logging to empty bloom (#13502)

---
 pkg/bloomgateway/processor.go |  3 ++-
 pkg/storage/bloom/v1/fuse.go  | 17 +++++++++++++----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/pkg/bloomgateway/processor.go b/pkg/bloomgateway/processor.go
index 4dc02fef435f..9f0b2b8b8151 100644
--- a/pkg/bloomgateway/processor.go
+++ b/pkg/bloomgateway/processor.go
@@ -167,7 +167,8 @@ func (p *processor) processBlock(_ context.Context, bq *bloomshipper.CloseableBl
 		iters = append(iters, it)
 	}
 
-	fq := blockQuerier.Fuse(iters, p.logger)
+	logger := log.With(p.logger, "block", bq.BlockRef.String())
+	fq := blockQuerier.Fuse(iters, logger)
 
 	start := time.Now()
 	err = fq.Run()
diff --git a/pkg/storage/bloom/v1/fuse.go b/pkg/storage/bloom/v1/fuse.go
index 264e456161a0..2a6f74d590b8 100644
--- a/pkg/storage/bloom/v1/fuse.go
+++ b/pkg/storage/bloom/v1/fuse.go
@@ -299,15 +299,24 @@ func (fq *FusedQuerier) runSeries(schema Schema, series *SeriesWithOffsets, reqs
 
 		// Test each bloom individually
 		bloom := fq.bq.blooms.At()
-		for j, req := range reqs {
-			// TODO(owen-d): this is a stopgap to avoid filtering broken blooms until we find their cause.
-			// In the case we don't have any data in the bloom, don't filter any chunks.
-			if bloom.ScalableBloomFilter.Count() == 0 {
+
+		// TODO(owen-d): this is a stopgap to avoid filtering broken blooms until we find their cause.
+		// In the case we don't have any data in the bloom, don't filter any chunks.
+		if bloom.ScalableBloomFilter.Count() == 0 {
+			level.Warn(fq.logger).Log(
+				"msg", "Found bloom with no data",
+				"offset_page", offset.Page,
+				"offset_bytes", offset.ByteOffset,
+			)
+
+			for j := range reqs {
 				for k := range inputs[j].InBlooms {
 					inputs[j].found[k] = true
 				}
 			}
+		}
 
+		for j, req := range reqs {
 			// shortcut: series level removal
 			// we can skip testing chunk keys individually if the bloom doesn't match
 			// the query.