Merge pull request #14288 from prometheus/superq/pick_14285

Tune default GOGC

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## unreleased
 
+This release changes the default for GOGC, the Go runtime control for the trade-off between excess memory use and CPU usage. We have found that Prometheus operates with minimal additional CPU usage, but greatly reduced memory by adjusting the upstream Go default from 100 to 75.
+
+* [CHANGE] Runtime: Change GOGC threshold from 50 to 75 #14285
+
 ## 2.53.0-rc.0 / 2024-06-06
 
 This release changes the default for GOGC, the Go runtime control for the trade-off between excess memory use and CPU usage. We have found that Prometheus operates with minimal additional CPU usage, but greatly reduced memory by adjusting the upstream Go default from 100 to 50.

config/config.go

@@ -154,7 +154,7 @@ var (
 
 	DefaultRuntimeConfig = RuntimeConfig{
 		// Go runtime tuning.
-		GoGC: 50,
+		GoGC: 75,
 	}
 
 	// DefaultScrapeConfig is the default scrape configuration.

docs/configuration/configuration.md

@@ -125,7 +125,7 @@ runtime:
   # Configure the Go garbage collector GOGC parameter
   # See: https://tip.golang.org/doc/gc-guide#GOGC
   # Lowering this number increases CPU usage.
-  [ gogc: <int> | default = 50 ]
+  [ gogc: <int> | default = 75 ]
 
 # Rule files specifies a list of globs. Rules and alerts are read from
 # all matching files.