mcs: fix checkMembershipCh blocking (tikv#7272)

close tikv#7207 Signed-off-by: lhy1024 <[email protected]> Co-authored-by: ti-chi-bot[bot] <108142056+ti-chi-bot[bot]@users.noreply.github.com>
rleungx · Dec 1, 2023 · 511bb06 · 511bb06
1 parent 7736243
commit 511bb06
Showing 1 changed file with 9 additions and 2 deletions.
diff --git a/pkg/mcs/scheduling/server/cluster.go b/pkg/mcs/scheduling/server/cluster.go
@@ -206,7 +206,7 @@ func (c *Cluster) AllocID() (uint64, error) {
 	defer cancel()
 	resp, err := client.AllocID(ctx, &pdpb.AllocIDRequest{Header: &pdpb.RequestHeader{ClusterId: c.clusterID}})
 	if err != nil {
-		c.checkMembershipCh <- struct{}{}
+		c.triggerMembershipCheck()
 		return 0, err
 	}
 	return resp.GetId(), nil
@@ -215,12 +215,19 @@ func (c *Cluster) AllocID() (uint64, error) {
 func (c *Cluster) getAPIServerLeaderClient() (pdpb.PDClient, error) {
 	cli := c.apiServerLeader.Load()
 	if cli == nil {
-		c.checkMembershipCh <- struct{}{}
+		c.triggerMembershipCheck()
 		return nil, errors.New("API server leader is not found")
 	}
 	return cli.(pdpb.PDClient), nil
 }
 
+func (c *Cluster) triggerMembershipCheck() {
+	select {
+	case c.checkMembershipCh <- struct{}{}:
+	default: // avoid blocking
+	}
+}
+
 // SwitchAPIServerLeader switches the API server leader.
 func (c *Cluster) SwitchAPIServerLeader(new pdpb.PDClient) bool {
 	old := c.apiServerLeader.Load()