Simplify apply by handling membership apply through the same applyV3 stack

server/etcdserver/apply/apply.go

@@ -63,13 +63,13 @@ type Result struct {
 	Trace *traceutil.Trace
 }
 
-type applyFunc func(r *pb.InternalRaftRequest) *Result
+type applyFunc func(*pb.InternalRaftRequest, membership.ShouldApplyV3) *Result
 
 // applierV3 is the interface for processing V3 raft messages
 type applierV3 interface {
 	// Apply executes the generic portion of application logic for the current applier, but
 	// delegates the actual execution to the applyFunc method.
-	Apply(r *pb.InternalRaftRequest, applyFunc applyFunc) *Result
+	Apply(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3, applyFunc applyFunc) *Result
 
 	Put(p *pb.PutRequest) (*pb.PutResponse, *traceutil.Trace, error)
 	Range(r *pb.RangeRequest) (*pb.RangeResponse, *traceutil.Trace, error)
@@ -103,6 +103,9 @@ type applierV3 interface {
 	RoleDelete(ua *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error)
 	UserList(ua *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error)
 	RoleList(ua *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error)
+	ClusterVersionSet(r *membershippb.ClusterVersionSetRequest, shouldApplyV3 membership.ShouldApplyV3)
+	ClusterMemberAttrSet(r *membershippb.ClusterMemberAttrSetRequest, shouldApplyV3 membership.ShouldApplyV3)
+	DowngradeInfoSet(r *membershippb.DowngradeInfoSetRequest, shouldApplyV3 membership.ShouldApplyV3)
 }
 
 type ApplierOptions struct {
@@ -135,8 +138,8 @@ func newApplierV3Backend(opts ApplierOptions) applierV3 {
 	}
 }
 
-func (a *applierV3backend) Apply(r *pb.InternalRaftRequest, applyFunc applyFunc) *Result {
-	return applyFunc(r)
+func (a *applierV3backend) Apply(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3, applyFunc applyFunc) *Result {
+	return applyFunc(r, shouldApplyV3)
 }
 
 func (a *applierV3backend) Put(p *pb.PutRequest) (resp *pb.PutResponse, trace *traceutil.Trace, err error) {
@@ -384,39 +387,25 @@ func (a *applierV3backend) RoleList(r *pb.AuthRoleListRequest) (*pb.AuthRoleList
 	return resp, err
 }
 
-type ApplierMembership struct {
-	lg             *zap.Logger
-	cluster        *membership.RaftCluster
-	snapshotServer SnapshotServer
-}
-
-func NewApplierMembership(lg *zap.Logger, cluster *membership.RaftCluster, snapshotServer SnapshotServer) *ApplierMembership {
-	return &ApplierMembership{
-		lg:             lg,
-		cluster:        cluster,
-		snapshotServer: snapshotServer,
-	}
-}
-
-func (a *ApplierMembership) ClusterVersionSet(r *membershippb.ClusterVersionSetRequest, shouldApplyV3 membership.ShouldApplyV3) {
-	prevVersion := a.cluster.Version()
+func (a *applierV3backend) ClusterVersionSet(r *membershippb.ClusterVersionSetRequest, shouldApplyV3 membership.ShouldApplyV3) {
+	prevVersion := a.options.Cluster.Version()
 	newVersion := semver.Must(semver.NewVersion(r.Ver))
-	a.cluster.SetVersion(newVersion, api.UpdateCapability, shouldApplyV3)
+	a.options.Cluster.SetVersion(newVersion, api.UpdateCapability, shouldApplyV3)
 	// Force snapshot after cluster version downgrade.
 	if prevVersion != nil && newVersion.LessThan(*prevVersion) {
-		lg := a.lg
+		lg := a.options.Logger
 		if lg != nil {
 			lg.Info("Cluster version downgrade detected, forcing snapshot",
 				zap.String("prev-cluster-version", prevVersion.String()),
 				zap.String("new-cluster-version", newVersion.String()),
 			)
 		}
-		a.snapshotServer.ForceSnapshot()
+		a.options.SnapshotServer.ForceSnapshot()
 	}
 }
 
-func (a *ApplierMembership) ClusterMemberAttrSet(r *membershippb.ClusterMemberAttrSetRequest, shouldApplyV3 membership.ShouldApplyV3) {
-	a.cluster.UpdateAttributes(
+func (a *applierV3backend) ClusterMemberAttrSet(r *membershippb.ClusterMemberAttrSetRequest, shouldApplyV3 membership.ShouldApplyV3) {
+	a.options.Cluster.UpdateAttributes(
 		types.ID(r.Member_ID),
 		membership.Attributes{
 			Name:       r.MemberAttributes.Name,
@@ -426,12 +415,12 @@ func (a *ApplierMembership) ClusterMemberAttrSet(r *membershippb.ClusterMemberAt
 	)
 }
 
-func (a *ApplierMembership) DowngradeInfoSet(r *membershippb.DowngradeInfoSetRequest, shouldApplyV3 membership.ShouldApplyV3) {
+func (a *applierV3backend) DowngradeInfoSet(r *membershippb.DowngradeInfoSetRequest, shouldApplyV3 membership.ShouldApplyV3) {
 	d := version.DowngradeInfo{Enabled: false}
 	if r.Enabled {
 		d = version.DowngradeInfo{Enabled: true, TargetVersion: r.Ver}
 	}
-	a.cluster.SetDowngradeInfo(&d, shouldApplyV3)
+	a.options.Cluster.SetDowngradeInfo(&d, shouldApplyV3)
 }
 
 type quotaApplierV3 struct {

server/etcdserver/apply/apply_auth.go

@@ -20,6 +20,7 @@ import (
 	pb "go.etcd.io/etcd/api/v3/etcdserverpb"
 	"go.etcd.io/etcd/pkg/v3/traceutil"
 	"go.etcd.io/etcd/server/v3/auth"
+	"go.etcd.io/etcd/server/v3/etcdserver/api/membership"
 	"go.etcd.io/etcd/server/v3/etcdserver/txn"
 	"go.etcd.io/etcd/server/v3/lease"
 )
@@ -40,7 +41,7 @@ func newAuthApplierV3(as auth.AuthStore, base applierV3, lessor lease.Lessor) *a
 	return &authApplierV3{applierV3: base, as: as, lessor: lessor}
 }
 
-func (aa *authApplierV3) Apply(r *pb.InternalRaftRequest, applyFunc applyFunc) *Result {
+func (aa *authApplierV3) Apply(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3, applyFunc applyFunc) *Result {
 	aa.mu.Lock()
 	defer aa.mu.Unlock()
 	if r.Header != nil {
@@ -56,7 +57,7 @@ func (aa *authApplierV3) Apply(r *pb.InternalRaftRequest, applyFunc applyFunc) *
 			return &Result{Err: err}
 		}
 	}
-	ret := aa.applierV3.Apply(r, applyFunc)
+	ret := aa.applierV3.Apply(r, shouldApplyV3, applyFunc)
 	aa.authInfo.Username = ""
 	aa.authInfo.Revision = 0
 	return ret

server/etcdserver/apply/apply_auth_test.go

@@ -44,7 +44,7 @@ func dummyIndexWaiter(_ uint64) <-chan struct{} {
 	return ch
 }
 
-func dummyApplyFunc(_ *pb.InternalRaftRequest) *Result {
+func dummyApplyFunc(_ *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3) *Result {
 	return &Result{}
 }
 
@@ -217,7 +217,7 @@ func TestAuthApplierV3_Apply(t *testing.T) {
 	mustCreateRolesAndEnableAuth(t, authApplier)
 	for _, tc := range tcs {
 		t.Run(tc.name, func(t *testing.T) {
-			result := authApplier.Apply(tc.request, dummyApplyFunc)
+			result := authApplier.Apply(tc.request, membership.ApplyBoth, dummyApplyFunc)
 			require.Equalf(t, result, tc.expectResult, "Apply: got %v, expect: %v", result, tc.expectResult)
 		})
 	}
@@ -384,7 +384,7 @@ func TestAuthApplierV3_AdminPermission(t *testing.T) {
 			if tc.adminPermissionNeeded {
 				tc.request.Header = &pb.RequestHeader{Username: userReadOnly}
 			}
-			result := authApplier.Apply(tc.request, dummyApplyFunc)
+			result := authApplier.Apply(tc.request, membership.ApplyBoth, dummyApplyFunc)
 			require.Equalf(t, errors.Is(result.Err, auth.ErrPermissionDenied), tc.adminPermissionNeeded, "Admin permission needed")
 		})
 	}

server/etcdserver/apply/uber_applier.go

@@ -21,13 +21,14 @@ import (
 	"go.uber.org/zap"
 
 	pb "go.etcd.io/etcd/api/v3/etcdserverpb"
+	"go.etcd.io/etcd/server/v3/etcdserver/api/membership"
 	"go.etcd.io/etcd/server/v3/etcdserver/api/v3alarm"
 	"go.etcd.io/etcd/server/v3/etcdserver/txn"
 	"go.etcd.io/etcd/server/v3/storage/mvcc"
 )
 
 type UberApplier interface {
-	Apply(r *pb.InternalRaftRequest) *Result
+	Apply(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3) *Result
 }
 
 type uberApplier struct {
@@ -78,18 +79,18 @@ func (a *uberApplier) restoreAlarms() {
 	}
 }
 
-func (a *uberApplier) Apply(r *pb.InternalRaftRequest) *Result {
+func (a *uberApplier) Apply(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3) *Result {
 	// We first execute chain of Apply() calls down the hierarchy:
 	// (i.e. CorruptApplier -> CappedApplier -> Auth -> Quota -> Backend),
 	// then dispatch() unpacks the request to a specific method (like Put),
 	// that gets executed down the hierarchy again:
 	// i.e. CorruptApplier.Put(CappedApplier.Put(...(BackendApplier.Put(...)))).
-	return a.applyV3.Apply(r, a.dispatch)
+	return a.applyV3.Apply(r, shouldApplyV3, a.dispatch)
 }
 
 // dispatch translates the request (r) into appropriate call (like Put) on
 // the underlying applyV3 object.
-func (a *uberApplier) dispatch(r *pb.InternalRaftRequest) *Result {
+func (a *uberApplier) dispatch(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3) *Result {
 	op := "unknown"
 	ar := &Result{}
 	defer func(start time.Time) {
@@ -101,6 +102,31 @@ func (a *uberApplier) dispatch(r *pb.InternalRaftRequest) *Result {
 		}
 	}(time.Now())
 
+	switch {
+	case r.ClusterVersionSet != nil:
+		op = "ClusterVersionSet" // Implemented in 3.5.x
+		a.applyV3.ClusterVersionSet(r.ClusterVersionSet, shouldApplyV3)
+		return ar
+	case r.ClusterMemberAttrSet != nil:
+		op = "ClusterMemberAttrSet" // Implemented in 3.5.x
+		a.applyV3.ClusterMemberAttrSet(r.ClusterMemberAttrSet, shouldApplyV3)
+		return ar
+	case r.DowngradeInfoSet != nil:
+		op = "DowngradeInfoSet" // Implemented in 3.5.x
+		a.applyV3.DowngradeInfoSet(r.DowngradeInfoSet, shouldApplyV3)
+		return ar
+	case r.DowngradeVersionTest != nil:
+		op = "DowngradeVersionTest" // Implemented in 3.6 for test only
+		// do nothing, we are just to ensure etcdserver don't panic in case
+		// users(test cases) intentionally inject DowngradeVersionTestRequest
+		// into the WAL files.
+		return ar
+	default:
+	}
+	if !shouldApplyV3 {
+		return nil
+	}
+
 	switch {
 	case r.Range != nil:
 		op = "Range"

server/etcdserver/apply/uber_applier_test.go

@@ -130,13 +130,13 @@ func TestUberApplier_Alarm_Corrupt(t *testing.T) {
 			MemberID: memberID,
 			Alarm:    pb.AlarmType_CORRUPT,
 		},
-	})
+	}, membership.ApplyBoth)
 	require.NotNil(t, result)
 	require.NoError(t, result.Err)
 
 	for _, tc := range tcs {
 		t.Run(tc.name, func(t *testing.T) {
-			result = ua.Apply(tc.request)
+			result = ua.Apply(tc.request, membership.ApplyBoth)
 			require.NotNil(t, result)
 			require.Equalf(t, tc.expectError, result.Err, "Apply: got %v, expect: %v", result.Err, tc.expectError)
 		})
@@ -232,13 +232,13 @@ func TestUberApplier_Alarm_Quota(t *testing.T) {
 			MemberID: memberID,
 			Alarm:    pb.AlarmType_NOSPACE,
 		},
-	})
+	}, membership.ApplyBoth)
 	require.NotNil(t, result)
 	require.NoError(t, result.Err)
 
 	for _, tc := range tcs {
 		t.Run(tc.name, func(t *testing.T) {
-			result = ua.Apply(tc.request)
+			result = ua.Apply(tc.request, membership.ApplyBoth)
 			require.NotNil(t, result)
 			require.Equalf(t, tc.expectError, result.Err, "Apply: got %v, expect: %v", result.Err, tc.expectError)
 		})
@@ -255,11 +255,11 @@ func TestUberApplier_Alarm_Deactivate(t *testing.T) {
 			MemberID: memberID,
 			Alarm:    pb.AlarmType_NOSPACE,
 		},
-	})
+	}, membership.ApplyBoth)
 	require.NotNil(t, result)
 	require.NoError(t, result.Err)
 
-	result = ua.Apply(&pb.InternalRaftRequest{Put: &pb.PutRequest{Key: []byte(key)}})
+	result = ua.Apply(&pb.InternalRaftRequest{Put: &pb.PutRequest{Key: []byte(key)}}, membership.ApplyBoth)
 	require.NotNil(t, result)
 	require.Equalf(t, errors.ErrNoSpace, result.Err, "Apply: got %v, expect: %v", result.Err, errors.ErrNoSpace)
 
@@ -270,11 +270,11 @@ func TestUberApplier_Alarm_Deactivate(t *testing.T) {
 			MemberID: memberID,
 			Alarm:    pb.AlarmType_NOSPACE,
 		},
-	})
+	}, membership.ApplyBoth)
 	require.NotNil(t, result)
 	require.NoError(t, result.Err)
 
-	result = ua.Apply(&pb.InternalRaftRequest{Put: &pb.PutRequest{Key: []byte(key)}})
+	result = ua.Apply(&pb.InternalRaftRequest{Put: &pb.PutRequest{Key: []byte(key)}}, membership.ApplyBoth)
 	require.NotNil(t, result)
 	assert.NoError(t, result.Err)
 }

server/etcdserver/server.go

@@ -62,7 +62,6 @@ import (
 	"go.etcd.io/etcd/server/v3/etcdserver/apply"
 	"go.etcd.io/etcd/server/v3/etcdserver/cindex"
 	"go.etcd.io/etcd/server/v3/etcdserver/errors"
-	"go.etcd.io/etcd/server/v3/etcdserver/txn"
 	serverversion "go.etcd.io/etcd/server/v3/etcdserver/version"
 	"go.etcd.io/etcd/server/v3/features"
 	"go.etcd.io/etcd/server/v3/lease"
@@ -1985,7 +1984,7 @@ func (s *EtcdServer) applyEntryNormal(e *raftpb.Entry, shouldApplyV3 membership.
 		if !needResult && raftReq.Txn != nil {
 			removeNeedlessRangeReqs(raftReq.Txn)
 		}
-		ar = s.applyInternalRaftRequest(&raftReq, shouldApplyV3)
+		ar = s.uberApply.Apply(&raftReq, shouldApplyV3)
 	}
 
 	// do not re-toApply applied entries.
@@ -2021,42 +2020,6 @@ func (s *EtcdServer) applyEntryNormal(e *raftpb.Entry, shouldApplyV3 membership.
 	})
 }
 
-func (s *EtcdServer) applyInternalRaftRequest(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3) *apply.Result {
-	if r.ClusterVersionSet == nil && r.ClusterMemberAttrSet == nil && r.DowngradeInfoSet == nil && r.DowngradeVersionTest == nil {
-		if !shouldApplyV3 {
-			return nil
-		}
-		return s.uberApply.Apply(r)
-	}
-	membershipApplier := apply.NewApplierMembership(s.lg, s.cluster, s)
-	op := "unknown"
-	defer func(start time.Time) {
-		txn.ApplySecObserve("v3", op, true, time.Since(start))
-		txn.WarnOfExpensiveRequest(s.lg, s.Cfg.WarningApplyDuration, start, &pb.InternalRaftStringer{Request: r}, nil, nil)
-	}(time.Now())
-	switch {
-	case r.ClusterVersionSet != nil:
-		op = "ClusterVersionSet" // Implemented in 3.5.x
-		membershipApplier.ClusterVersionSet(r.ClusterVersionSet, shouldApplyV3)
-		return &apply.Result{}
-	case r.ClusterMemberAttrSet != nil:
-		op = "ClusterMemberAttrSet" // Implemented in 3.5.x
-		membershipApplier.ClusterMemberAttrSet(r.ClusterMemberAttrSet, shouldApplyV3)
-	case r.DowngradeInfoSet != nil:
-		op = "DowngradeInfoSet" // Implemented in 3.5.x
-		membershipApplier.DowngradeInfoSet(r.DowngradeInfoSet, shouldApplyV3)
-	case r.DowngradeVersionTest != nil:
-		op = "DowngradeVersionTest" // Implemented in 3.6 for test only
-		// do nothing, we are just to ensure etcdserver don't panic in case
-		// users(test cases) intentionally inject DowngradeVersionTestRequest
-		// into the WAL files.
-	default:
-		s.lg.Panic("not implemented apply", zap.Stringer("raft-request", r))
-		return nil
-	}
-	return &apply.Result{}
-}
-
 func noSideEffect(r *pb.InternalRaftRequest) bool {
 	return r.Range != nil || r.AuthUserGet != nil || r.AuthRoleGet != nil || r.AuthStatus != nil
 }

server/etcdserver/server_test.go

@@ -149,7 +149,7 @@ func TestApplyRepeat(t *testing.T) {
 
 type uberApplierMock struct{}
 
-func (uberApplierMock) Apply(r *pb.InternalRaftRequest) *apply2.Result {
+func (uberApplierMock) Apply(r *pb.InternalRaftRequest, shouldApplyV3 membership.ShouldApplyV3) *apply2.Result {
 	return &apply2.Result{}
 }