From 90672d74de6ce9a7f4ea273897fbdfdc952f7dad Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Wed, 17 Jan 2024 13:46:24 +0200
Subject: [PATCH] lib/storage: do not prefetch metric names for small number of
metricIDs
This eliminates prefetchedMetricIDsLock lock contention for queries, which return less than 500 time series.
This is a follow-up for 9d886a2eb028ff5b8bb6b91f1d8214c165200bb6
---
lib/storage/storage.go | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/lib/storage/storage.go b/lib/storage/storage.go
index d003fbaace..4e9461065a 100644
--- a/lib/storage/storage.go
+++ b/lib/storage/storage.go
@@ -1213,8 +1213,9 @@ func (s *Storage) SearchMetricNames(qt *querytracer.Tracer, tfss []*TagFilters,
func (s *Storage) prefetchMetricNames(qt *querytracer.Tracer, accountID, projectID uint32, srcMetricIDs []uint64, deadline uint64) error {
qt = qt.NewChild("prefetch metric names for %d metricIDs", len(srcMetricIDs))
defer qt.Done()
- if len(srcMetricIDs) == 0 {
- qt.Printf("nothing to prefetch")
+
+ if len(srcMetricIDs) < 500 {
+ qt.Printf("skip pre-fetching metric names for low number of metric ids=%d", len(srcMetricIDs))
return nil
}
@@ -1232,7 +1233,7 @@ func (s *Storage) prefetchMetricNames(qt *querytracer.Tracer, accountID, project
qt.Printf("%d out of %d metric names must be pre-fetched", len(metricIDs), len(srcMetricIDs))
if len(metricIDs) < 500 {
// It is cheaper to skip pre-fetching and obtain metricNames inline.
- qt.Printf("skip pre-fetching metric names for low number of metrid ids=%d", len(metricIDs))
+ qt.Printf("skip pre-fetching metric names for low number of missing metric ids=%d", len(metricIDs))
return nil
}
atomic.AddUint64(&s.slowMetricNameLoads, uint64(len(metricIDs)))