From f1c4f3109b5f5af414dd5d2dec6adebc25709365 Mon Sep 17 00:00:00 2001
From: lhy1024 <admin@liudos.us>
Date: Thu, 9 Nov 2023 10:54:50 +0800
Subject: [PATCH] checker: refactor fixOrphanPeers

Signed-off-by: lhy1024 <admin@liudos.us>
---
 pkg/schedule/checker/rule_checker.go | 43 ++++++++++++++++------------
 server/cluster/cluster_test.go       |  2 +-
 2 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/pkg/schedule/checker/rule_checker.go b/pkg/schedule/checker/rule_checker.go
index c4e7c242dea..e09c008626d 100644
--- a/pkg/schedule/checker/rule_checker.go
+++ b/pkg/schedule/checker/rule_checker.go
@@ -449,23 +449,31 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 		return nil, nil
 	}
 
-	isUnhealthyPeer := func(id uint64) bool {
-		for _, downPeer := range region.GetDownPeers() {
-			if downPeer.Peer.GetId() == id {
+	isPendingPeer := func(id uint64) bool {
+		for _, pendingPeer := range region.GetPendingPeers() {
+			if pendingPeer.GetId() == id {
 				return true
 			}
 		}
-		for _, pendingPeer := range region.GetPendingPeers() {
-			if pendingPeer.GetId() == id {
+		return false
+	}
+
+	isDownPeer := func(id uint64) bool {
+		for _, downPeer := range region.GetDownPeers() {
+			if downPeer.Peer.GetId() == id {
 				return true
 			}
 		}
 		return false
 	}
 
-	isDisconnectedPeer := func(p *metapb.Peer) bool {
+	isUnhealthyPeer := func(id uint64) bool {
+		return isPendingPeer(id) || isDownPeer(id)
+	}
+
+	isInDisconnectedStore := func(p *metapb.Peer) bool {
 		// avoid to meet down store when fix orphan peers,
-		// Isdisconnected is more strictly than IsUnhealthy.
+		// isInDisconnectedStore is usually more strictly than IsUnhealthy.
 		store := c.cluster.GetStore(p.GetStoreId())
 		if store == nil {
 			return true
@@ -475,16 +483,15 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 
 	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 isInDisconnectedStore(p) {
+				return p, true
 			}
-			if isDisconnectedPeer(p) {
+			if isDownPeer(p.GetId()) {
 				return p, true
 			}
+			if isPendingPeer(p.GetId()) {
+				return nil, true
+			}
 		}
 		return nil, false
 	}
@@ -517,7 +524,7 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 				continue
 			}
 			// make sure the orphan peer is healthy.
-			if isUnhealthyPeer(orphanPeer.GetId()) || isDisconnectedPeer(orphanPeer) {
+			if isUnhealthyPeer(orphanPeer.GetId()) || isInDisconnectedStore(orphanPeer) {
 				continue
 			}
 			// no consider witness in this path.
@@ -525,7 +532,7 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 				continue
 			}
 			// pinDownPeer's store should be disconnected, because we use more strict judge before.
-			if !isDisconnectedPeer(pinDownPeer) {
+			if !isInDisconnectedStore(pinDownPeer) {
 				continue
 			}
 			// check if down peer can replace with orphan peer.
@@ -539,7 +546,7 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 					return operator.CreatePromoteLearnerOperatorAndRemovePeer("replace-down-peer-with-orphan-peer", c.cluster, region, orphanPeer, pinDownPeer)
 				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 == destRole && isDisconnectedPeer(pinDownPeer) && !dstStore.IsDisconnected():
+				case orphanPeerRole == destRole && isInDisconnectedStore(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.
@@ -557,7 +564,7 @@ func (c *RuleChecker) fixOrphanPeers(region *core.RegionInfo, fit *placement.Reg
 		hasHealthPeer := false
 		var disconnectedPeer *metapb.Peer
 		for _, orphanPeer := range fit.OrphanPeers {
-			if isDisconnectedPeer(orphanPeer) {
+			if isInDisconnectedStore(orphanPeer) {
 				disconnectedPeer = orphanPeer
 				break
 			}
diff --git a/server/cluster/cluster_test.go b/server/cluster/cluster_test.go
index 89c9ea32f19..70782e27cd3 100644
--- a/server/cluster/cluster_test.go
+++ b/server/cluster/cluster_test.go
@@ -2792,7 +2792,7 @@ func TestReplica(t *testing.T) {
 	re.NoError(dispatchHeartbeat(co, region, stream))
 	waitNoResponse(re, stream)
 
-	// Remove peer from store 4.
+	// Remove peer from store 3.
 	re.NoError(tc.addLeaderRegion(2, 1, 2, 3, 4))
 	region = tc.GetRegion(2)
 	re.NoError(dispatchHeartbeat(co, region, stream))