checker: replace down check with disconnect check when fixing orphan peer

pkg/core/store.go

@@ -551,6 +551,9 @@ var (
 // tikv's store heartbeat for a short time, maybe caused by process restart or
 // temporary network failure.
 func (s *StoreInfo) IsDisconnected() bool {
+	if s == nil {
+		return true
+	}
 	return s.DownTime() > storeDisconnectDuration
 }
 

pkg/schedule/checker/rule_checker.go

@@ -447,7 +447,7 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 	if len(fit.OrphanPeers) == 0 {
 		return nil, nil
 	}
-	var pinDownPeer *metapb.Peer
+
 	isUnhealthyPeer := func(id uint64) bool {
 		for _, downPeer := range region.GetDownPeers() {
 			if downPeer.Peer.GetId() == id {
@@ -461,31 +461,41 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 		}
 		return false
 	}
+
+	isDisconnectedPeer := func(p *metapb.Peer) bool {
+		// avoid to meet down store when fix orphan peers,
+		// Isdisconnected is more strictly than IsUnhealthy.
+		return c.cluster.GetStore(p.GetStoreId()).IsDisconnected()
+	}
+
+	checkDownPeer := func(peers []*metapb.Peer) (*metapb.Peer, bool) {
+		for _, p := range peers {
+			if isUnhealthyPeer(p.GetId()) {
+				// make sure is down peer.
+				if region.GetDownPeer(p.GetId()) != nil {
+					return p, true
+				}
+				return nil, true
+			}
+			if isDisconnectedPeer(p) {
+				return p, true
+			}
+		}
+		return nil, false
+	}
+
 	// remove orphan peers only when all rules are satisfied (count+role) and all peers selected
 	// by RuleFits is not pending or down.
+	var pinDownPeer *metapb.Peer
 	hasUnhealthyFit := false
-loopFits:
 	for _, rf := range fit.RuleFits {
 		if !rf.IsSatisfied() {
 			hasUnhealthyFit = true
 			break
 		}
-		for _, p := range rf.Peers {
-			if isUnhealthyPeer(p.GetId()) {
-				// make sure is down peer.
-				if region.GetDownPeer(p.GetId()) != nil {
-					pinDownPeer = p
-				}
-				hasUnhealthyFit = true
-				break loopFits
-			}
-			// avoid to meet down store when fix orpahn peers,
-			// Isdisconnected is more strictly than IsUnhealthy.
-			if c.cluster.GetStore(p.GetStoreId()).IsDisconnected() {
-				hasUnhealthyFit = true
-				pinDownPeer = p
-				break loopFits
-			}
+		pinDownPeer, hasUnhealthyFit = checkDownPeer(rf.Peers)
+		if hasUnhealthyFit {
+			break
 		}
 	}
 
@@ -502,15 +512,15 @@ loopFits:
 				continue
 			}
 			// make sure the orphan peer is healthy.
-			if isUnhealthyPeer(orphanPeer.GetId()) {
+			if isUnhealthyPeer(orphanPeer.GetId()) || isDisconnectedPeer(orphanPeer) {
 				continue
 			}
 			// no consider witness in this path.
 			if pinDownPeer.GetIsWitness() || orphanPeer.GetIsWitness() {
 				continue
 			}
-			// down peer's store should be down.
-			if !c.isStoreDownTimeHitMaxDownTime(pinDownPeer.GetStoreId()) {
+			// down peer's store should be disconnected
+			if !isDisconnectedPeer(pinDownPeer) {
 				continue
 			}
 			// check if down peer can replace with orphan peer.
@@ -525,7 +535,7 @@ loopFits:
 				case orphanPeerRole == metapb.PeerRole_Voter && destRole == metapb.PeerRole_Learner:
 					return operator.CreateDemoteLearnerOperatorAndRemovePeer("replace-down-peer-with-orphan-peer", c.cluster, region, orphanPeer, pinDownPeer)
 				case orphanPeerRole == metapb.PeerRole_Voter && destRole == metapb.PeerRole_Voter &&
-					c.cluster.GetStore(pinDownPeer.GetStoreId()).IsDisconnected() && !dstStore.IsDisconnected():
+					isDisconnectedPeer(pinDownPeer) && !dstStore.IsDisconnected():
 					return operator.CreateRemovePeerOperator("remove-replaced-orphan-peer", c.cluster, 0, region, pinDownPeer.GetStoreId())
 				default:
 					// destRole should not same with orphanPeerRole. if role is same, it fit with orphanPeer should be better than now.
@@ -541,8 +551,12 @@ loopFits:
 		hasHealthPeer := false
 		for _, orphanPeer := range fit.OrphanPeers {
 			if isUnhealthyPeer(orphanPeer.GetId()) {
-				ruleCheckerRemoveOrphanPeerCounter.Inc()
-				return operator.CreateRemovePeerOperator("remove-orphan-peer", c.cluster, 0, region, orphanPeer.StoreId)
+				checkerCounter.WithLabelValues("rule_checker", "remove-orphan-peer").Inc()
+				return operator.CreateRemovePeerOperator("remove-unhealthy-orphan-peer", c.cluster, 0, region, orphanPeer.StoreId)
+			}
+			if isDisconnectedPeer(orphanPeer) {
+				checkerCounter.WithLabelValues("rule_checker", "remove-orphan-peer").Inc()
+				return operator.CreateRemovePeerOperator("remove-disconnected-orphan-peer", c.cluster, 0, region, orphanPeer.StoreId)
 			}
 			if hasHealthPeer {
 				// there already exists a healthy orphan peer, so we can remove other orphan Peers.

pkg/schedule/checker/rule_checker_test.go

@@ -235,7 +235,7 @@ func (suite *ruleCheckerTestSuite) TestFixToManyOrphanPeers() {
 	suite.cluster.PutRegion(region)
 	op = suite.rc.Check(suite.cluster.GetRegion(1))
 	suite.NotNil(op)
-	suite.Equal("remove-orphan-peer", op.Desc())
+	suite.Equal("remove-unhealthy-orphan-peer", op.Desc())
 	suite.Equal(uint64(4), op.Step(0).(operator.RemovePeer).FromStore)
 }
 
@@ -702,7 +702,7 @@ func (suite *ruleCheckerTestSuite) TestPriorityFixOrphanPeer() {
 	suite.cluster.PutRegion(testRegion)
 	op = suite.rc.Check(suite.cluster.GetRegion(1))
 	suite.NotNil(op)
-	suite.Equal("remove-orphan-peer", op.Desc())
+	suite.Equal("remove-unhealthy-orphan-peer", op.Desc())
 	suite.IsType(remove, op.Step(0))
 	// Ref #3521
 	suite.cluster.SetStoreOffline(2)
@@ -723,6 +723,73 @@ func (suite *ruleCheckerTestSuite) TestPriorityFixOrphanPeer() {
 	suite.Equal("remove-orphan-peer", op.Desc())
 }
 
+// Ref https://github.com/tikv/pd/issues/7249 https://github.com/tikv/tikv/issues/15799
+func (suite *ruleCheckerTestSuite) TestFixOrphanPeerWithDisconnectedStoreAndRuleChanged() {
+	// init cluster with 5 replicas
+	suite.cluster.AddLabelsStore(1, 1, map[string]string{"host": "host1"})
+	suite.cluster.AddLabelsStore(2, 1, map[string]string{"host": "host2"})
+	suite.cluster.AddLabelsStore(3, 1, map[string]string{"host": "host3"})
+	suite.cluster.AddLabelsStore(4, 1, map[string]string{"host": "host4"})
+	suite.cluster.AddLabelsStore(5, 1, map[string]string{"host": "host5"})
+	storeIDs := []uint64{1, 2, 3, 4, 5}
+	suite.cluster.AddLeaderRegionWithRange(1, "", "", storeIDs[0], storeIDs[1:]...)
+	rule := &placement.Rule{
+		GroupID:  "pd",
+		ID:       "default",
+		Role:     placement.Voter,
+		Count:    5,
+		StartKey: []byte{},
+		EndKey:   []byte{},
+	}
+	suite.ruleManager.SetRule(rule)
+	op := suite.rc.Check(suite.cluster.GetRegion(1))
+	suite.Nil(op)
+
+	// set store 1, 2 to disconnected
+	suite.cluster.SetStoreDisconnect(1)
+	suite.cluster.SetStoreDisconnect(2)
+
+	// change rule to 3 replicas
+	rule = &placement.Rule{
+		GroupID:  "pd",
+		ID:       "default",
+		Role:     placement.Voter,
+		Count:    3,
+		StartKey: []byte{},
+		EndKey:   []byte{},
+		Override: true,
+	}
+	suite.ruleManager.SetRule(rule)
+
+	// remove store 1 from region 1
+	op = suite.rc.Check(suite.cluster.GetRegion(1))
+	suite.NotNil(op)
+	suite.Equal("remove-replaced-orphan-peer", op.Desc())
+	newLeaderID := op.Step(0).(operator.TransferLeader).ToStore
+	removedPeerID := op.Step(1).(operator.RemovePeer).FromStore
+	r1 := suite.cluster.GetRegion(1)
+	r1 = r1.Clone(
+		core.WithLeader(r1.GetPeer(newLeaderID)),
+		core.WithRemoveStorePeer(removedPeerID))
+	suite.cluster.PutRegion(r1)
+	r1 = suite.cluster.GetRegion(1)
+	suite.Len(r1.GetPeers(), 4)
+
+	// remove store 2 from region 1
+	op = suite.rc.Check(suite.cluster.GetRegion(1))
+	suite.NotNil(op)
+	suite.Equal("remove-replaced-orphan-peer", op.Desc())
+	removedPeerID = op.Step(0).(operator.RemovePeer).FromStore
+	r1 = r1.Clone(core.WithRemoveStorePeer(removedPeerID))
+	suite.cluster.PutRegion(r1)
+	r1 = suite.cluster.GetRegion(1)
+	suite.Len(r1.GetPeers(), 3)
+	for _, p := range r1.GetPeers() {
+		suite.NotEqual(p.GetStoreId(), 1)
+		suite.NotEqual(p.GetStoreId(), 2)
+	}
+}
+
 func (suite *ruleCheckerTestSuite) TestPriorityFitHealthWithDifferentRole1() {
 	suite.cluster.SetEnableUseJointConsensus(true)
 	suite.cluster.AddLabelsStore(1, 1, map[string]string{"host": "host1"})