From 1078081aec0a1b68beaf22ad483347d732bb0b48 Mon Sep 17 00:00:00 2001
From: Xiaochao Dong <the.xcdong@gmail.com>
Date: Thu, 4 Aug 2022 16:09:14 +0800
Subject: [PATCH] Fix race condition when updating lastSeriesID during loading
 chunk snapshot (#11099)

Signed-off-by: Xiaochao Dong (@damnever) <the.xcdong@gmail.com>
---
 tsdb/head_wal.go | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tsdb/head_wal.go b/tsdb/head_wal.go
index f6990d8bf..277410ad1 100644
--- a/tsdb/head_wal.go
+++ b/tsdb/head_wal.go
@@ -921,8 +921,12 @@ func (h *Head) loadChunkSnapshot() (int, int, map[chunks.HeadSeriesRef]*memSerie
 					return
 				}
 				localRefSeries[csr.ref] = series
-				if chunks.HeadSeriesRef(h.lastSeriesID.Load()) < series.ref {
-					h.lastSeriesID.Store(uint64(series.ref))
+				for {
+					seriesID := uint64(series.ref)
+					lastSeriesID := h.lastSeriesID.Load()
+					if lastSeriesID >= seriesID || h.lastSeriesID.CAS(lastSeriesID, seriesID) {
+						break
+					}
 				}
 
 				series.chunkRange = csr.chunkRange