From 187fd89c709b0aaeba2e75c996208a07d2f45d3f Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 11 Mar 2020 03:19:56 +0200
Subject: [PATCH] lib/promscrape: consistently update `/targets` page after
 SIGHUP

---
 lib/promscrape/scraper.go      |  8 ++++++++
 lib/promscrape/targetstatus.go | 26 ++++++++++++++++++++------
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/lib/promscrape/scraper.go b/lib/promscrape/scraper.go
index c69e92286..0b872eb2e 100644
--- a/lib/promscrape/scraper.go
+++ b/lib/promscrape/scraper.go
@@ -64,6 +64,8 @@ func runScraper(configFile string, pushData func(wr *prompbmarshal.WriteRequest)
 	if err != nil {
 		logger.Fatalf("cannot parse `file_sd_config` from %q: %s", configFile, err)
 	}
+	tsmGlobal.RegisterAll(swsStatic)
+	tsmGlobal.RegisterAll(swsFileSD)
 
 	mustStop := false
 	for !mustStop {
@@ -98,9 +100,13 @@ func runScraper(configFile string, pushData func(wr *prompbmarshal.WriteRequest)
 			if err != nil {
 				logger.Errorf("cannot parse `file_sd_config` from %q: %s; continuing with the previous config", configFile, err)
 			}
+			tsmGlobal.UnregisterAll(swsStatic)
+			tsmGlobal.UnregisterAll(swsFileSD)
 			cfg = cfgNew
 			swsStatic = swsStaticNew
 			swsFileSD = swsFileSDNew
+			tsmGlobal.RegisterAll(swsStatic)
+			tsmGlobal.RegisterAll(swsFileSD)
 		case <-globalStopCh:
 			mustStop = true
 		}
@@ -160,7 +166,9 @@ func runFileSDScrapers(sws []ScrapeWork, cfg *Config, pushData func(wr *prompbma
 				goto waitForChans
 			}
 			logger.Infof("restarting scrapers for changed `file_sd_config` targets")
+			tsmGlobal.UnregisterAll(sws)
 			sws = swsNew
+			tsmGlobal.RegisterAll(sws)
 		case <-stopCh:
 			mustStop = true
 		}
diff --git a/lib/promscrape/targetstatus.go b/lib/promscrape/targetstatus.go
index 74e382633..390ab355e 100644
--- a/lib/promscrape/targetstatus.go
+++ b/lib/promscrape/targetstatus.go
@@ -35,6 +35,25 @@ func (tsm *targetStatusMap) Reset() {
 	tsm.mu.Unlock()
 }
 
+func (tsm *targetStatusMap) RegisterAll(sws []ScrapeWork) {
+	tsm.mu.Lock()
+	for i := range sws {
+		sw := &sws[i]
+		tsm.m[sw.ScrapeURL] = targetStatus{
+			sw: sw,
+		}
+	}
+	tsm.mu.Unlock()
+}
+
+func (tsm *targetStatusMap) UnregisterAll(sws []ScrapeWork) {
+	tsm.mu.Lock()
+	for i := range sws {
+		delete(tsm.m, sws[i].ScrapeURL)
+	}
+	tsm.mu.Unlock()
+}
+
 func (tsm *targetStatusMap) Update(sw *ScrapeWork, up bool, scrapeTime, scrapeDuration int64, err error) {
 	tsm.mu.Lock()
 	tsm.m[sw.ScrapeURL] = targetStatus{
@@ -50,12 +69,7 @@ func (tsm *targetStatusMap) Update(sw *ScrapeWork, up bool, scrapeTime, scrapeDu
 func (tsm *targetStatusMap) WriteHumanReadable(w io.Writer) {
 	byJob := make(map[string][]targetStatus)
 	tsm.mu.Lock()
-	for k, st := range tsm.m {
-		if st.getDurationFromLastScrape() > 10*st.sw.ScrapeInterval {
-			// Remove obsolete targets
-			delete(tsm.m, k)
-			continue
-		}
+	for _, st := range tsm.m {
 		job := ""
 		label := promrelabel.GetLabelByName(st.sw.Labels, "job")
 		if label != nil {