lease: Persist remainingTTL to prevent indefinite auto-renewal of long lived leases

Documentation/dev-guide/api_reference_v3.md

@@ -476,6 +476,31 @@ Empty field.
 
 
 
+##### message `LeaseCheckpoint` (etcdserver/etcdserverpb/rpc.proto)
+
+| Field | Description | Type |
+| ----- | ----------- | ---- |
+| ID | ID is the lease ID to checkpoint. | int64 |
+| remaining_TTL | Remaining_TTL is the remaining time until expiry of the lease. | int64 |
+
+
+
+##### message `LeaseCheckpointRequest` (etcdserver/etcdserverpb/rpc.proto)
+
+| Field | Description | Type |
+| ----- | ----------- | ---- |
+| checkpoints |  | (slice of) LeaseCheckpoint |
+
+
+
+##### message `LeaseCheckpointResponse` (etcdserver/etcdserverpb/rpc.proto)
+
+| Field | Description | Type |
+| ----- | ----------- | ---- |
+| header |  | ResponseHeader |
+
+
+
 ##### message `LeaseGrantRequest` (etcdserver/etcdserverpb/rpc.proto)
 
 | Field | Description | Type |
@@ -903,6 +928,7 @@ Empty field.
 | ----- | ----------- | ---- |
 | ID |  | int64 |
 | TTL |  | int64 |
+| RemainingTTL |  | int64 |
 
 
 

clientv3/snapshot/v3_snapshot.go

@@ -373,7 +373,7 @@ func (s *v3Manager) saveDB() error {
 	be := backend.NewDefaultBackend(dbpath)
 
 	// a lessor never timeouts leases
-	lessor := lease.NewLessor(be, math.MaxInt64)
+	lessor := lease.NewLessor(s.lg, be, lease.LessorConfig{MinLeaseTTL: math.MaxInt64})
 
 	mvs := mvcc.NewStore(s.lg, be, lessor, (*initIndex)(&commit))
 	txn := mvs.Write()

etcdserver/apply.go

@@ -58,6 +58,8 @@ type applierV3 interface {
 	LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error)
 	LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error)
 
+	LeaseCheckpoint(lc *pb.LeaseCheckpointRequest) (*pb.LeaseCheckpointResponse, error)
+
 	Alarm(*pb.AlarmRequest) (*pb.AlarmResponse, error)
 
 	Authenticate(r *pb.InternalAuthenticateRequest) (*pb.AuthenticateResponse, error)
@@ -130,6 +132,8 @@ func (a *applierV3backend) Apply(r *pb.InternalRaftRequest) *applyResult {
 		ar.resp, ar.err = a.s.applyV3.LeaseGrant(r.LeaseGrant)
 	case r.LeaseRevoke != nil:
 		ar.resp, ar.err = a.s.applyV3.LeaseRevoke(r.LeaseRevoke)
+	case r.LeaseCheckpoint != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseCheckpoint(r.LeaseCheckpoint)
 	case r.Alarm != nil:
 		ar.resp, ar.err = a.s.applyV3.Alarm(r.Alarm)
 	case r.Authenticate != nil:
@@ -582,6 +586,16 @@ func (a *applierV3backend) LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevo
 	return &pb.LeaseRevokeResponse{Header: newHeader(a.s)}, err
 }
 
+func (a *applierV3backend) LeaseCheckpoint(lc *pb.LeaseCheckpointRequest) (*pb.LeaseCheckpointResponse, error) {
+	for _, c := range lc.Checkpoints {
+		err := a.s.lessor.Checkpoint(lease.LeaseID(c.ID), c.Remaining_TTL)
+		if err != nil {
+			return &pb.LeaseCheckpointResponse{Header: newHeader(a.s)}, err
+		}
+	}
+	return &pb.LeaseCheckpointResponse{Header: newHeader(a.s)}, nil
+}
+
 func (a *applierV3backend) Alarm(ar *pb.AlarmRequest) (*pb.AlarmResponse, error) {
 	resp := &pb.AlarmResponse{}
 	oldCount := len(a.s.alarmStore.Get(ar.Alarm))

etcdserver/config.go

@@ -140,6 +140,9 @@ type ServerConfig struct {
 	Debug bool
 
 	ForceNewCluster bool
+
+	// LeaseCheckpointInterval time.Duration is the wait duration between lease checkpoints.
+	LeaseCheckpointInterval time.Duration
 }
 
 // VerifyBootstrap sanity-checks the initial config for bootstrap case