From e6356e64bd6fe68e7568699e2c7f345745a12b3b Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Tue, 2 Apr 2024 17:07:00 +0100
Subject: [PATCH] Scraping: drop series cache when resizing symbol table

Clear caches by restarting scraping loops: each loop assumes it has
exclusive ownership of its cache, so we can't come in from another
goroutine and change it.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
---
 scrape/scrape.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scrape/scrape.go b/scrape/scrape.go
index 57bb164b7..68411a62e 100644
--- a/scrape/scrape.go
+++ b/scrape/scrape.go
@@ -376,6 +376,7 @@ func (sp *scrapePool) checkSymbolTable() {
 		} else if sp.symbolTable.Len() > 2*sp.initialSymbolTableLen {
 			sp.symbolTable = labels.NewSymbolTable()
 			sp.initialSymbolTableLen = 0
+			sp.restartLoops(false) // To drop all caches.
 		}
 		sp.lastSymbolTableCheck = time.Now()
 	}