diff --git a/pkg/domain/domain.go b/pkg/domain/domain.go
index e12d0c200617e..60e5cc444ac16 100644
--- a/pkg/domain/domain.go
+++ b/pkg/domain/domain.go
@@ -2407,6 +2407,7 @@ func (do *Domain) updateStatsWorker(ctx sessionctx.Context, owner owner.Manager)
 	defer util.Recover(metrics.LabelDomain, "updateStatsWorker", nil, false)
 	logutil.BgLogger().Info("updateStatsWorker started.")
 	lease := do.statsLease
+	// We need to have different nodes trigger tasks at different times to avoid the herd effect.
 	randDuration := time.Duration(rand.Int63n(int64(time.Minute)))
 	deltaUpdateTicker := time.NewTicker(20*lease + randDuration)
 	gcStatsTicker := time.NewTicker(100 * lease)