v3rpc, rpctypes: add error types for timeouts

etcdserver/api/v3rpc/rpctypes/error.go

@@ -51,9 +51,11 @@ var (
 	ErrGRPCPermissionNotGranted = grpc.Errorf(codes.FailedPrecondition, "etcdserver: permission is not granted to the role")
 	ErrGRPCAuthNotEnabled       = grpc.Errorf(codes.FailedPrecondition, "etcdserver: authentication is not enabled")
 
-	ErrGRPCNoLeader   = grpc.Errorf(codes.Unavailable, "etcdserver: no leader")
-	ErrGRPCNotCapable = grpc.Errorf(codes.Unavailable, "etcdserver: not capable")
-	ErrGRPCStopped    = grpc.Errorf(codes.Unavailable, "etcdserver: server stopped")
+	ErrGRPCNoLeader               = grpc.Errorf(codes.Unavailable, "etcdserver: no leader")
+	ErrGRPCNotCapable             = grpc.Errorf(codes.Unavailable, "etcdserver: not capable")
+	ErrGRPCStopped                = grpc.Errorf(codes.Unavailable, "etcdserver: server stopped")
+	ErrGRPCTimeout                = grpc.Errorf(codes.Unavailable, "etcdserver: request timed out")
+	ErrGRPCTimeoutDueToLeaderFail = grpc.Errorf(codes.Unavailable, "etcdserver: request timed out, possibly due to previous leader failure")
 
 	errStringToError = map[string]error{
 		grpc.ErrorDesc(ErrGRPCEmptyKey):     ErrGRPCEmptyKey,
@@ -86,9 +88,11 @@ var (
 		grpc.ErrorDesc(ErrGRPCPermissionNotGranted): ErrGRPCPermissionNotGranted,
 		grpc.ErrorDesc(ErrGRPCAuthNotEnabled):       ErrGRPCAuthNotEnabled,
 
-		grpc.ErrorDesc(ErrGRPCNoLeader):   ErrGRPCNoLeader,
-		grpc.ErrorDesc(ErrGRPCNotCapable): ErrGRPCNotCapable,
-		grpc.ErrorDesc(ErrGRPCStopped):    ErrGRPCStopped,
+		grpc.ErrorDesc(ErrGRPCNoLeader):               ErrGRPCNoLeader,
+		grpc.ErrorDesc(ErrGRPCNotCapable):             ErrGRPCNotCapable,
+		grpc.ErrorDesc(ErrGRPCStopped):                ErrGRPCStopped,
+		grpc.ErrorDesc(ErrGRPCTimeout):                ErrGRPCTimeout,
+		grpc.ErrorDesc(ErrGRPCTimeoutDueToLeaderFail): ErrGRPCTimeoutDueToLeaderFail,
 	}
 
 	// client-side error
@@ -122,9 +126,11 @@ var (
 	ErrPermissionNotGranted = Error(ErrGRPCPermissionNotGranted)
 	ErrAuthNotEnabled       = Error(ErrGRPCAuthNotEnabled)
 
-	ErrNoLeader   = Error(ErrGRPCNoLeader)
-	ErrNotCapable = Error(ErrGRPCNotCapable)
-	ErrStopped    = Error(ErrGRPCStopped)
+	ErrNoLeader               = Error(ErrGRPCNoLeader)
+	ErrNotCapable             = Error(ErrGRPCNotCapable)
+	ErrStopped                = Error(ErrGRPCStopped)
+	ErrTimeout                = Error(ErrGRPCTimeout)
+	ErrTimeoutDueToLeaderFail = Error(ErrGRPCTimeoutDueToLeaderFail)
 )
 
 // EtcdError defines gRPC server errors.

etcdserver/api/v3rpc/util.go

@@ -32,7 +32,6 @@ func togRPCError(err error) error {
 		return rpctypes.ErrGRPCFutureRev
 	case lease.ErrLeaseNotFound:
 		return rpctypes.ErrGRPCLeaseNotFound
-	// TODO: handle error from raft and timeout
 	case etcdserver.ErrRequestTooLarge:
 		return rpctypes.ErrGRPCRequestTooLarge
 	case etcdserver.ErrNoSpace:
@@ -40,6 +39,15 @@ func togRPCError(err error) error {
 	case etcdserver.ErrTooManyRequests:
 		return rpctypes.ErrTooManyRequests
 
+	case etcdserver.ErrNoLeader:
+		return rpctypes.ErrGRPCNoLeader
+	case etcdserver.ErrStopped:
+		return rpctypes.ErrGRPCStopped
+	case etcdserver.ErrTimeout:
+		return rpctypes.ErrGRPCTimeout
+	case etcdserver.ErrTimeoutDueToLeaderFail:
+		return rpctypes.ErrGRPCTimeoutDueToLeaderFail
+
 	case auth.ErrRootUserNotExist:
 		return rpctypes.ErrGRPCRootUserNotExist
 	case auth.ErrRootRoleNotExist: