From 10918b8a0f4d2d94f20dd6b94da13b7445333464 Mon Sep 17 00:00:00 2001
From: Florian <git@hedius.eu>
Date: Thu, 2 Nov 2023 16:24:13 +0100
Subject: [PATCH] add option for remote read concurrencylimit (#245)

---
 config/config.go  | 12 +++++++-----
 prometheus/run.go | 33 +++++++++++++++++----------------
 2 files changed, 24 insertions(+), 21 deletions(-)

diff --git a/config/config.go b/config/config.go
index 1742e3177..06f477031 100644
--- a/config/config.go
+++ b/config/config.go
@@ -278,11 +278,12 @@ type Carbonlink struct {
 
 // Prometheus configuration
 type Prometheus struct {
-	Listen         string        `toml:"listen"         json:"listen"         comment:"listen addr for prometheus ui and api"`
-	ExternalURLRaw string        `toml:"external-url"   json:"external-url"   comment:"allows to set URL for redirect manually"`
-	ExternalURL    *url.URL      `toml:"-"              json:"-"`
-	PageTitle      string        `toml:"page-title"     json:"page-title"`
-	LookbackDelta  time.Duration `toml:"lookback-delta" json:"lookback-delta"`
+	Listen         	           string        `toml:"listen"                        json:"listen"                        comment:"listen addr for prometheus ui and api"`
+	ExternalURLRaw 	           string        `toml:"external-url"                  json:"external-url"                  comment:"allows to set URL for redirect manually"`
+	ExternalURL    	           *url.URL      `toml:"-"                             json:"-"`
+	PageTitle      	           string        `toml:"page-title"                    json:"page-title"`
+	LookbackDelta  	           time.Duration `toml:"lookback-delta"                json:"lookback-delta"`
+	RemoteReadConcurrencyLimit int           `toml:"remote-read-concurrency-limit" json:"remote-read-concurrency-limit" comment:"concurrently handled remote read requests"`
 }
 
 const (
@@ -396,6 +397,7 @@ func New() *Config {
 			PageTitle:      "Prometheus Time Series Collection and Processing Server",
 			Listen:         ":9092",
 			LookbackDelta:  5 * time.Minute,
+			RemoteReadConcurrencyLimit: 10,
 		},
 		Debug: Debug{
 			Directory:        "",
diff --git a/prometheus/run.go b/prometheus/run.go
index b9ec9a3e4..147d9876e 100644
--- a/prometheus/run.go
+++ b/prometheus/run.go
@@ -49,22 +49,23 @@ func Run(config *config.Config) error {
 	notifierManager := notifier.NewManager(&notifier.Options{}, zapLogger)
 
 	promHandler := web.New(zapLogger, &web.Options{
-		ListenAddress:   config.Prometheus.Listen,
-		MaxConnections:  500,
-		Storage:         storage,
-		ExemplarStorage: &nopExemplarQueryable{},
-		ExternalURL:     config.Prometheus.ExternalURL,
-		RoutePrefix:     "/",
-		QueryEngine:     queryEngine,
-		ScrapeManager:   scrapeManager,
-		RuleManager:     rulesManager,
-		Flags:           make(map[string]string),
-		LocalStorage:    storage,
-		Gatherer:        &nopGatherer{},
-		Notifier:        notifierManager,
-		CORSOrigin:      corsOrigin,
-		PageTitle:       config.Prometheus.PageTitle,
-		LookbackDelta:   config.Prometheus.LookbackDelta,
+		ListenAddress:              config.Prometheus.Listen,
+		MaxConnections:             500,
+		Storage:                    storage,
+		ExemplarStorage:            &nopExemplarQueryable{},
+		ExternalURL:                config.Prometheus.ExternalURL,
+		RoutePrefix:                "/",
+		QueryEngine:                queryEngine,
+		ScrapeManager:              scrapeManager,
+		RuleManager:                rulesManager,
+		Flags:                      make(map[string]string),
+		LocalStorage:               storage,
+		Gatherer:                   &nopGatherer{},
+		Notifier:                   notifierManager,
+		CORSOrigin:                 corsOrigin,
+		PageTitle:                  config.Prometheus.PageTitle,
+		LookbackDelta:              config.Prometheus.LookbackDelta,
+		RemoteReadConcurrencyLimit: config.Prometheus.RemoteReadConcurrencyLimit,
 	})
 
 	promHandler.ApplyConfig(&promConfig.Config{})