From 7b60aae18c6e8453eaf5b0f5d04f86db506b96f4 Mon Sep 17 00:00:00 2001
From: Herve Nicol <12008875+hervenicol@users.noreply.github.com>
Date: Tue, 19 Sep 2023 16:00:40 +0200
Subject: [PATCH] improve agent shards calculation

---
 CHANGELOG.md                     | 4 ++++
 pkg/prometheusquerier/querier.go | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 570ee5fc2..14b6c6cdf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- computation of number of shards: rely on max number of series over the last 6h.
+
 ## [4.48.0] - 2023-09-19
 
 ### Changed
diff --git a/pkg/prometheusquerier/querier.go b/pkg/prometheusquerier/querier.go
index e64250f93..9ed603d08 100644
--- a/pkg/prometheusquerier/querier.go
+++ b/pkg/prometheusquerier/querier.go
@@ -29,7 +29,7 @@ func QueryTSDBHeadSeries(cluster string) (float64, error) {
 	api := v1.NewAPI(c)
 
 	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
-	val, _, err := api.Query(ctx, "prometheus_tsdb_head_series", time.Now()) // Ignoring warnings for now.
+	val, _, err := api.Query(ctx, "max_over_time(prometheus_tsdb_head_series[6h])", time.Now()) // Ignoring warnings for now.
 	cancel()
 	if err != nil {
 		return 0, err