From c7d44292bddcd309eec93a818dcb364c20cdd30a Mon Sep 17 00:00:00 2001
From: lhy1024 <admin@liudos.us>
Date: Fri, 16 Aug 2024 01:22:11 +0800
Subject: [PATCH] mcs: fix potential data race in scheduling server

Signed-off-by: lhy1024 <admin@liudos.us>
---
 pkg/mcs/scheduling/server/server.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pkg/mcs/scheduling/server/server.go b/pkg/mcs/scheduling/server/server.go
index 47a7cf9962b..093b759ce1c 100644
--- a/pkg/mcs/scheduling/server/server.go
+++ b/pkg/mcs/scheduling/server/server.go
@@ -207,6 +207,11 @@ func (s *Server) updateAPIServerMemberLoop() {
 				cc, err := s.GetDelegateClient(ctx, s.GetTLSConfig(), ep.ClientURLs[0])
 				if err != nil {
 					log.Info("failed to get delegate client", errs.ZapError(err))
+					continue
+				}
+				if !s.IsServing() {
+					// double check
+					break
 				}
 				if s.cluster.SwitchAPIServerLeader(pdpb.NewPDClient(cc)) {
 					if status.Leader != curLeader {