operator: allows to skip placement rules checks (#5458) (#5462)

close #5401, ref #5458

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>
Signed-off-by: nolouch <nolouch@gmail.com>
Signed-off-by: HunDunDM <hundundm@gmail.com>

Co-authored-by: 混沌DM <hundundm@gmail.com>
Co-authored-by: nolouch <nolouch@gmail.com>
Co-authored-by: HunDunDM <hundundm@gmail.com>

server/schedule/operator/builder.go

@@ -29,11 +29,13 @@ import (
 )
 
 // Builder is used to create operators. Usage:
-//     op, err := NewBuilder(desc, cluster, region).
-//                 RemovePeer(store1).
-//                 AddPeer(peer1).
-//                 SetLeader(store2).
-//                 Build(kind)
+//
+//	op, err := NewBuilder(desc, cluster, region).
+//	            RemovePeer(store1).
+//	            AddPeer(peer1).
+//	            SetLeader(store2).
+//	            Build(kind)
+//
 // The generated Operator will choose the most appropriate execution order
 // according to various constraints.
 type Builder struct {
@@ -53,8 +55,9 @@ type Builder struct {
 	targetLeaderStoreID uint64
 	err                 error
 
-	// skip origin check flags
+	// skip check flags
 	skipOriginJointStateCheck bool
+	skipPlacementRulesCheck   bool
 
 	// build flags
 	useJointConsensus bool
@@ -80,6 +83,11 @@ func SkipOriginJointStateCheck(b *Builder) {
 	b.skipOriginJointStateCheck = true
 }
 
+// SkipPlacementRulesCheck lets the builder skip the placement rules check for origin and target peers.
+func SkipPlacementRulesCheck(b *Builder) {
+	b.skipPlacementRulesCheck = true
+}
+
 // NewBuilder creates a Builder.
 func NewBuilder(desc string, cluster opt.Cluster, region *core.RegionInfo, opts ...BuilderOption) *Builder {
 	b := &Builder{
@@ -123,7 +131,7 @@ func NewBuilder(desc string, cluster opt.Cluster, region *core.RegionInfo, opts
 
 	// placement rules
 	var rules []*placement.Rule
-	if err == nil && cluster.GetOpts().IsPlacementRulesEnabled() {
+	if err == nil && !b.skipPlacementRulesCheck && cluster.GetOpts().IsPlacementRulesEnabled() {
 		fit := cluster.GetRuleManager().FitRegion(cluster, region)
 		for _, rf := range fit.RuleFits {
 			rules = append(rules, rf.Rule)
@@ -737,7 +745,7 @@ func (b *Builder) allowLeader(peer *metapb.Peer, ignoreClusterLimit bool) bool {
 	}
 
 	// placement rules
-	if len(b.rules) == 0 {
+	if b.skipPlacementRulesCheck || len(b.rules) == 0 {
 		return true
 	}
 	for _, r := range b.rules {

server/schedule/operator/create_operator.go

@@ -67,7 +67,7 @@ func CreateTransferLeaderOperator(desc string, cluster opt.Cluster, region *core
 
 // CreateForceTransferLeaderOperator creates an operator that transfers the leader from a source store to a target store forcible.
 func CreateForceTransferLeaderOperator(desc string, cluster opt.Cluster, region *core.RegionInfo, sourceStoreID uint64, targetStoreID uint64, kind OpKind) (*Operator, error) {
-	return NewBuilder(desc, cluster, region, SkipOriginJointStateCheck).
+	return NewBuilder(desc, cluster, region, SkipOriginJointStateCheck, SkipPlacementRulesCheck).
 		SetLeader(targetStoreID).
 		EnableForceTargetLeader().
 		Build(kind)
@@ -219,7 +219,7 @@ func CreateScatterRegionOperator(desc string, cluster opt.Cluster, origin *core.
 
 // CreateLeaveJointStateOperator creates an operator that let region leave joint state.
 func CreateLeaveJointStateOperator(desc string, cluster opt.Cluster, origin *core.RegionInfo) (*Operator, error) {
-	b := NewBuilder(desc, cluster, origin, SkipOriginJointStateCheck)
+	b := NewBuilder(desc, cluster, origin, SkipOriginJointStateCheck, SkipPlacementRulesCheck)
 
 	if b.err == nil && !core.IsInJointState(origin.GetPeers()...) {
 		b.err = errors.Errorf("cannot build leave joint state operator for region which is not in joint state")

server/schedule/operator/create_operator_test.go

@@ -16,6 +16,7 @@ package operator
 
 import (
 	"context"
+	"encoding/hex"
 	"strings"
 
 	. "github.com/pingcap/check"
@@ -1073,3 +1074,65 @@ func (s *testCreateOperatorSuite) TestMoveRegionWithoutJointConsensus(c *C) {
 		}
 	}
 }
+
+var _ = Suite(&testCreateOperatorWithRulesSuite{})
+
+type testCreateOperatorWithRulesSuite struct{}
+
+// Ref https://github.com/tikv/pd/issues/5401
+func (s *testCreateOperatorWithRulesSuite) TestCreateLeaveJointStateOperatorWithoutFitRules(c *C) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	opts := config.NewTestOptions()
+	cluster := mockcluster.NewCluster(ctx, opts)
+	err := cluster.SetRules([]*placement.Rule{
+		{
+			GroupID:     "pd",
+			ID:          "default",
+			StartKeyHex: hex.EncodeToString([]byte("")),
+			EndKeyHex:   hex.EncodeToString([]byte("")),
+			Role:        placement.Voter,
+			Count:       1,
+		},
+		{
+			GroupID:     "t1",
+			ID:          "t1",
+			StartKeyHex: hex.EncodeToString([]byte("a")),
+			EndKeyHex:   hex.EncodeToString([]byte("b")),
+			Role:        placement.Voter,
+			Count:       1,
+		},
+		{
+			GroupID:     "t2",
+			ID:          "t2",
+			StartKeyHex: hex.EncodeToString([]byte("b")),
+			EndKeyHex:   hex.EncodeToString([]byte("c")),
+			Role:        placement.Voter,
+			Count:       1,
+		},
+	})
+	c.Assert(err, IsNil)
+	cluster.AddRegionStore(1, 1)
+	cluster.AddRegionStore(2, 1)
+	cluster.AddRegionStore(3, 1)
+	cluster.AddRegionStore(4, 1)
+	originPeers := []*metapb.Peer{
+		{Id: 3, StoreId: 3, Role: metapb.PeerRole_DemotingVoter},
+		{Id: 4, StoreId: 4, Role: metapb.PeerRole_IncomingVoter},
+	}
+
+	region := core.NewRegionInfo(&metapb.Region{Id: 1, Peers: originPeers, StartKey: []byte("a"), EndKey: []byte("c")}, originPeers[0])
+	op, err := CreateLeaveJointStateOperator("test", cluster, region)
+	c.Assert(err, IsNil)
+	c.Assert(op.kind, Equals, OpLeader)
+	c.Assert(op.steps, HasLen, 2)
+	step0 := op.steps[0].(TransferLeader)
+	c.Assert(step0.FromStore, Equals, uint64(3))
+	c.Assert(step0.ToStore, Equals, uint64(4))
+	step1 := op.steps[1].(ChangePeerV2Leave)
+	c.Assert(step1.PromoteLearners, HasLen, 1)
+	c.Assert(step1.DemoteVoters, HasLen, 1)
+	c.Assert(step1.PromoteLearners[0].ToStore, Equals, uint64(4))
+	c.Assert(step1.DemoteVoters[0].ToStore, Equals, uint64(3))
+}