From 9954576fdbfd8407ab3dce30ff63959294bfeaf9 Mon Sep 17 00:00:00 2001
From: Yang Zhang <yang.zhang@pingcap.com>
Date: Wed, 5 Jul 2023 05:08:13 -0700
Subject: [PATCH] unsafe recovery: Fixing learner store being ignored error in
 7.1 (#6744)

ref tikv/pd#6690, ref tikv/pd#6710

Fix learner store/ replica being ignored error in auto detect mode.

Signed-off-by: Yang Zhang <yang.zhang@pingcap.com>

Co-authored-by: ti-chi-bot[bot] <108142056+ti-chi-bot[bot]@users.noreply.github.com>
---
 server/cluster/unsafe_recovery_controller.go  |  3 --
 .../unsafe_recovery_controller_test.go        | 42 +++++++++++++++++++
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/server/cluster/unsafe_recovery_controller.go b/server/cluster/unsafe_recovery_controller.go
index d54a331048e..6c2d5101928 100644
--- a/server/cluster/unsafe_recovery_controller.go
+++ b/server/cluster/unsafe_recovery_controller.go
@@ -706,9 +706,6 @@ func (u *unsafeRecoveryController) getFailedPeers(region *metapb.Region) []*meta
 
 	var failedPeers []*metapb.Peer
 	for _, peer := range region.Peers {
-		if peer.Role == metapb.PeerRole_Learner || peer.Role == metapb.PeerRole_DemotingVoter {
-			continue
-		}
 		if u.isFailed(peer) {
 			failedPeers = append(failedPeers, peer)
 		}
diff --git a/server/cluster/unsafe_recovery_controller_test.go b/server/cluster/unsafe_recovery_controller_test.go
index 6ef20fdb6b7..9a9eff293fc 100644
--- a/server/cluster/unsafe_recovery_controller_test.go
+++ b/server/cluster/unsafe_recovery_controller_test.go
@@ -554,6 +554,48 @@ func TestForceLeaderForCommitMerge(t *testing.T) {
 	re.Equal(demoteFailedVoter, recoveryController.GetStage())
 }
 
+// Failed learner replica/ store should be considered by auto-recover.
+func TestAutoDetectModeWithOneLearner(t *testing.T) {
+	re := require.New(t)
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	_, opt, _ := newTestScheduleConfig()
+	cluster := newTestRaftCluster(ctx, mockid.NewIDAllocator(), opt, storage.NewStorageWithMemoryBackend(), core.NewBasicCluster())
+	cluster.coordinator = newCoordinator(ctx, cluster, hbstream.NewTestHeartbeatStreams(ctx, cluster.meta.GetId(), cluster, true))
+	cluster.coordinator.run()
+	for _, store := range newTestStores(1, "6.0.0") {
+		re.NoError(cluster.PutStore(store.GetMeta()))
+	}
+	recoveryController := newUnsafeRecoveryController(cluster)
+	re.NoError(recoveryController.RemoveFailedStores(nil, 60, true))
+
+	storeReport := pdpb.StoreReport{
+		PeerReports: []*pdpb.PeerReport{
+			{
+				RaftState: &raft_serverpb.RaftLocalState{LastIndex: 10, HardState: &eraftpb.HardState{Term: 1, Commit: 10}},
+				RegionState: &raft_serverpb.RegionLocalState{
+					Region: &metapb.Region{
+						Id:          1001,
+						RegionEpoch: &metapb.RegionEpoch{ConfVer: 7, Version: 10},
+						Peers: []*metapb.Peer{
+							{Id: 11, StoreId: 1}, {Id: 12, StoreId: 2}, {Id: 13, StoreId: 3, Role: metapb.PeerRole_Learner}}}}},
+		},
+	}
+	req := newStoreHeartbeat(1, &storeReport)
+	req.StoreReport.Step = 1
+	resp := &pdpb.StoreHeartbeatResponse{}
+	recoveryController.HandleStoreHeartbeat(req, resp)
+	hasStore3AsFailedStore := false
+	for _, failedStore := range resp.RecoveryPlan.ForceLeader.FailedStores {
+		if failedStore == 3 {
+			hasStore3AsFailedStore = true
+			break
+		}
+	}
+	re.True(hasStore3AsFailedStore)
+}
+
 func TestAutoDetectMode(t *testing.T) {
 	re := require.New(t)
 	ctx, cancel := context.WithCancel(context.Background())