diff --git a/pkg/apis/proto/map/v1/map.pb.go b/pkg/apis/proto/map/v1/map.pb.go
index 7d615a9b..58f978de 100644
--- a/pkg/apis/proto/map/v1/map.pb.go
+++ b/pkg/apis/proto/map/v1/map.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/map/v1/map.proto
 
diff --git a/pkg/apis/proto/mapstream/v1/mapstream.pb.go b/pkg/apis/proto/mapstream/v1/mapstream.pb.go
index 2a2f2bd1..6a276ae2 100644
--- a/pkg/apis/proto/mapstream/v1/mapstream.pb.go
+++ b/pkg/apis/proto/mapstream/v1/mapstream.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/mapstream/v1/mapstream.proto
 
diff --git a/pkg/apis/proto/reduce/v1/reduce.pb.go b/pkg/apis/proto/reduce/v1/reduce.pb.go
index 5376e90a..597d4c7c 100644
--- a/pkg/apis/proto/reduce/v1/reduce.pb.go
+++ b/pkg/apis/proto/reduce/v1/reduce.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/reduce/v1/reduce.proto
 
diff --git a/pkg/apis/proto/sessionreduce/v1/sessionreduce.pb.go b/pkg/apis/proto/sessionreduce/v1/sessionreduce.pb.go
index 79cd3f65..fe19a9ae 100644
--- a/pkg/apis/proto/sessionreduce/v1/sessionreduce.pb.go
+++ b/pkg/apis/proto/sessionreduce/v1/sessionreduce.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/sessionreduce/v1/sessionreduce.proto
 
diff --git a/pkg/apis/proto/sideinput/v1/sideinput.pb.go b/pkg/apis/proto/sideinput/v1/sideinput.pb.go
index 5fd5b7cd..a117b3a1 100644
--- a/pkg/apis/proto/sideinput/v1/sideinput.pb.go
+++ b/pkg/apis/proto/sideinput/v1/sideinput.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/sideinput/v1/sideinput.proto
 
diff --git a/pkg/apis/proto/sink/v1/sink.pb.go b/pkg/apis/proto/sink/v1/sink.pb.go
index 0bc0a086..3f0dae1f 100644
--- a/pkg/apis/proto/sink/v1/sink.pb.go
+++ b/pkg/apis/proto/sink/v1/sink.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/sink/v1/sink.proto
 
@@ -22,6 +22,56 @@ const (
 	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
 )
 
+// Status is the status of the response.
+type Status int32
+
+const (
+	Status_SUCCESS  Status = 0
+	Status_FAILURE  Status = 1
+	Status_FALLBACK Status = 2
+)
+
+// Enum value maps for Status.
+var (
+	Status_name = map[int32]string{
+		0: "SUCCESS",
+		1: "FAILURE",
+		2: "FALLBACK",
+	}
+	Status_value = map[string]int32{
+		"SUCCESS":  0,
+		"FAILURE":  1,
+		"FALLBACK": 2,
+	}
+)
+
+func (x Status) Enum() *Status {
+	p := new(Status)
+	*p = x
+	return p
+}
+
+func (x Status) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (Status) Descriptor() protoreflect.EnumDescriptor {
+	return file_pkg_apis_proto_sink_v1_sink_proto_enumTypes[0].Descriptor()
+}
+
+func (Status) Type() protoreflect.EnumType {
+	return &file_pkg_apis_proto_sink_v1_sink_proto_enumTypes[0]
+}
+
+func (x Status) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Use Status.Descriptor instead.
+func (Status) EnumDescriptor() ([]byte, []int) {
+	return file_pkg_apis_proto_sink_v1_sink_proto_rawDescGZIP(), []int{0}
+}
+
 // *
 // SinkRequest represents a request element.
 type SinkRequest struct {
@@ -216,8 +266,8 @@ type SinkResponse_Result struct {
 
 	// id is the ID of the message, can be used to uniquely identify the message.
 	Id string `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
-	// success denotes the status of persisting to disk. if set to false, it means writing to sink for the message failed.
-	Success bool `protobuf:"varint,2,opt,name=success,proto3" json:"success,omitempty"`
+	// status denotes the status of persisting to sink. It can be SUCCESS, FAILURE, or FALLBACK.
+	Status Status `protobuf:"varint,2,opt,name=status,proto3,enum=sink.v1.Status" json:"status,omitempty"`
 	// err_msg is the error message, set it if success is set to false.
 	ErrMsg string `protobuf:"bytes,3,opt,name=err_msg,json=errMsg,proto3" json:"err_msg,omitempty"`
 }
@@ -261,11 +311,11 @@ func (x *SinkResponse_Result) GetId() string {
 	return ""
 }
 
-func (x *SinkResponse_Result) GetSuccess() bool {
+func (x *SinkResponse_Result) GetStatus() Status {
 	if x != nil {
-		return x.Success
+		return x.Status
 	}
-	return false
+	return Status_SUCCESS
 }
 
 func (x *SinkResponse_Result) GetErrMsg() string {
@@ -306,28 +356,32 @@ var file_pkg_apis_proto_sink_v1_sink_proto_rawDesc = []byte{
 	0x65, 0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x05, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x3a, 0x02,
 	0x38, 0x01, 0x22, 0x25, 0x0a, 0x0d, 0x52, 0x65, 0x61, 0x64, 0x79, 0x52, 0x65, 0x73, 0x70, 0x6f,
 	0x6e, 0x73, 0x65, 0x12, 0x14, 0x0a, 0x05, 0x72, 0x65, 0x61, 0x64, 0x79, 0x18, 0x01, 0x20, 0x01,
-	0x28, 0x08, 0x52, 0x05, 0x72, 0x65, 0x61, 0x64, 0x79, 0x22, 0x93, 0x01, 0x0a, 0x0c, 0x53, 0x69,
+	0x28, 0x08, 0x52, 0x05, 0x72, 0x65, 0x61, 0x64, 0x79, 0x22, 0xa2, 0x01, 0x0a, 0x0c, 0x53, 0x69,
 	0x6e, 0x6b, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x12, 0x36, 0x0a, 0x07, 0x72, 0x65,
 	0x73, 0x75, 0x6c, 0x74, 0x73, 0x18, 0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x1c, 0x2e, 0x73, 0x69,
 	0x6e, 0x6b, 0x2e, 0x76, 0x31, 0x2e, 0x53, 0x69, 0x6e, 0x6b, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e,
 	0x73, 0x65, 0x2e, 0x52, 0x65, 0x73, 0x75, 0x6c, 0x74, 0x52, 0x07, 0x72, 0x65, 0x73, 0x75, 0x6c,
-	0x74, 0x73, 0x1a, 0x4b, 0x0a, 0x06, 0x52, 0x65, 0x73, 0x75, 0x6c, 0x74, 0x12, 0x0e, 0x0a, 0x02,
-	0x69, 0x64, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x02, 0x69, 0x64, 0x12, 0x18, 0x0a, 0x07,
-	0x73, 0x75, 0x63, 0x63, 0x65, 0x73, 0x73, 0x18, 0x02, 0x20, 0x01, 0x28, 0x08, 0x52, 0x07, 0x73,
-	0x75, 0x63, 0x63, 0x65, 0x73, 0x73, 0x12, 0x17, 0x0a, 0x07, 0x65, 0x72, 0x72, 0x5f, 0x6d, 0x73,
-	0x67, 0x18, 0x03, 0x20, 0x01, 0x28, 0x09, 0x52, 0x06, 0x65, 0x72, 0x72, 0x4d, 0x73, 0x67, 0x32,
-	0x7a, 0x0a, 0x04, 0x53, 0x69, 0x6e, 0x6b, 0x12, 0x37, 0x0a, 0x06, 0x53, 0x69, 0x6e, 0x6b, 0x46,
-	0x6e, 0x12, 0x14, 0x2e, 0x73, 0x69, 0x6e, 0x6b, 0x2e, 0x76, 0x31, 0x2e, 0x53, 0x69, 0x6e, 0x6b,
-	0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x15, 0x2e, 0x73, 0x69, 0x6e, 0x6b, 0x2e, 0x76,
-	0x31, 0x2e, 0x53, 0x69, 0x6e, 0x6b, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x28, 0x01,
-	0x12, 0x39, 0x0a, 0x07, 0x49, 0x73, 0x52, 0x65, 0x61, 0x64, 0x79, 0x12, 0x16, 0x2e, 0x67, 0x6f,
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-	0x70, 0x74, 0x79, 0x1a, 0x16, 0x2e, 0x73, 0x69, 0x6e, 0x6b, 0x2e, 0x76, 0x31, 0x2e, 0x52, 0x65,
-	0x61, 0x64, 0x79, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x42, 0x38, 0x5a, 0x36, 0x67,
-	0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x6e, 0x75, 0x6d, 0x61, 0x70, 0x72,
-	0x6f, 0x6a, 0x2f, 0x6e, 0x75, 0x6d, 0x61, 0x66, 0x6c, 0x6f, 0x77, 0x2d, 0x67, 0x6f, 0x2f, 0x70,
-	0x6b, 0x67, 0x2f, 0x61, 0x70, 0x69, 0x73, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x73, 0x69,
-	0x6e, 0x6b, 0x2f, 0x76, 0x31, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+	0x74, 0x73, 0x1a, 0x5a, 0x0a, 0x06, 0x52, 0x65, 0x73, 0x75, 0x6c, 0x74, 0x12, 0x0e, 0x0a, 0x02,
+	0x69, 0x64, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52, 0x02, 0x69, 0x64, 0x12, 0x27, 0x0a, 0x06,
+	0x73, 0x74, 0x61, 0x74, 0x75, 0x73, 0x18, 0x02, 0x20, 0x01, 0x28, 0x0e, 0x32, 0x0f, 0x2e, 0x73,
+	0x69, 0x6e, 0x6b, 0x2e, 0x76, 0x31, 0x2e, 0x53, 0x74, 0x61, 0x74, 0x75, 0x73, 0x52, 0x06, 0x73,
+	0x74, 0x61, 0x74, 0x75, 0x73, 0x12, 0x17, 0x0a, 0x07, 0x65, 0x72, 0x72, 0x5f, 0x6d, 0x73, 0x67,
+	0x18, 0x03, 0x20, 0x01, 0x28, 0x09, 0x52, 0x06, 0x65, 0x72, 0x72, 0x4d, 0x73, 0x67, 0x2a, 0x30,
+	0x0a, 0x06, 0x53, 0x74, 0x61, 0x74, 0x75, 0x73, 0x12, 0x0b, 0x0a, 0x07, 0x53, 0x55, 0x43, 0x43,
+	0x45, 0x53, 0x53, 0x10, 0x00, 0x12, 0x0b, 0x0a, 0x07, 0x46, 0x41, 0x49, 0x4c, 0x55, 0x52, 0x45,
+	0x10, 0x01, 0x12, 0x0c, 0x0a, 0x08, 0x46, 0x41, 0x4c, 0x4c, 0x42, 0x41, 0x43, 0x4b, 0x10, 0x02,
+	0x32, 0x7a, 0x0a, 0x04, 0x53, 0x69, 0x6e, 0x6b, 0x12, 0x37, 0x0a, 0x06, 0x53, 0x69, 0x6e, 0x6b,
+	0x46, 0x6e, 0x12, 0x14, 0x2e, 0x73, 0x69, 0x6e, 0x6b, 0x2e, 0x76, 0x31, 0x2e, 0x53, 0x69, 0x6e,
+	0x6b, 0x52, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x1a, 0x15, 0x2e, 0x73, 0x69, 0x6e, 0x6b, 0x2e,
+	0x76, 0x31, 0x2e, 0x53, 0x69, 0x6e, 0x6b, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x28,
+	0x01, 0x12, 0x39, 0x0a, 0x07, 0x49, 0x73, 0x52, 0x65, 0x61, 0x64, 0x79, 0x12, 0x16, 0x2e, 0x67,
+	0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2e, 0x45,
+	0x6d, 0x70, 0x74, 0x79, 0x1a, 0x16, 0x2e, 0x73, 0x69, 0x6e, 0x6b, 0x2e, 0x76, 0x31, 0x2e, 0x52,
+	0x65, 0x61, 0x64, 0x79, 0x52, 0x65, 0x73, 0x70, 0x6f, 0x6e, 0x73, 0x65, 0x42, 0x38, 0x5a, 0x36,
+	0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x6e, 0x75, 0x6d, 0x61, 0x70,
+	0x72, 0x6f, 0x6a, 0x2f, 0x6e, 0x75, 0x6d, 0x61, 0x66, 0x6c, 0x6f, 0x77, 0x2d, 0x67, 0x6f, 0x2f,
+	0x70, 0x6b, 0x67, 0x2f, 0x61, 0x70, 0x69, 0x73, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2f, 0x73,
+	0x69, 0x6e, 0x6b, 0x2f, 0x76, 0x31, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -342,30 +396,33 @@ func file_pkg_apis_proto_sink_v1_sink_proto_rawDescGZIP() []byte {
 	return file_pkg_apis_proto_sink_v1_sink_proto_rawDescData
 }
 
+var file_pkg_apis_proto_sink_v1_sink_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
 var file_pkg_apis_proto_sink_v1_sink_proto_msgTypes = make([]protoimpl.MessageInfo, 5)
 var file_pkg_apis_proto_sink_v1_sink_proto_goTypes = []interface{}{
-	(*SinkRequest)(nil),           // 0: sink.v1.SinkRequest
-	(*ReadyResponse)(nil),         // 1: sink.v1.ReadyResponse
-	(*SinkResponse)(nil),          // 2: sink.v1.SinkResponse
-	nil,                           // 3: sink.v1.SinkRequest.HeadersEntry
-	(*SinkResponse_Result)(nil),   // 4: sink.v1.SinkResponse.Result
-	(*timestamppb.Timestamp)(nil), // 5: google.protobuf.Timestamp
-	(*emptypb.Empty)(nil),         // 6: google.protobuf.Empty
+	(Status)(0),                   // 0: sink.v1.Status
+	(*SinkRequest)(nil),           // 1: sink.v1.SinkRequest
+	(*ReadyResponse)(nil),         // 2: sink.v1.ReadyResponse
+	(*SinkResponse)(nil),          // 3: sink.v1.SinkResponse
+	nil,                           // 4: sink.v1.SinkRequest.HeadersEntry
+	(*SinkResponse_Result)(nil),   // 5: sink.v1.SinkResponse.Result
+	(*timestamppb.Timestamp)(nil), // 6: google.protobuf.Timestamp
+	(*emptypb.Empty)(nil),         // 7: google.protobuf.Empty
 }
 var file_pkg_apis_proto_sink_v1_sink_proto_depIdxs = []int32{
-	5, // 0: sink.v1.SinkRequest.event_time:type_name -> google.protobuf.Timestamp
-	5, // 1: sink.v1.SinkRequest.watermark:type_name -> google.protobuf.Timestamp
-	3, // 2: sink.v1.SinkRequest.headers:type_name -> sink.v1.SinkRequest.HeadersEntry
-	4, // 3: sink.v1.SinkResponse.results:type_name -> sink.v1.SinkResponse.Result
-	0, // 4: sink.v1.Sink.SinkFn:input_type -> sink.v1.SinkRequest
-	6, // 5: sink.v1.Sink.IsReady:input_type -> google.protobuf.Empty
-	2, // 6: sink.v1.Sink.SinkFn:output_type -> sink.v1.SinkResponse
-	1, // 7: sink.v1.Sink.IsReady:output_type -> sink.v1.ReadyResponse
-	6, // [6:8] is the sub-list for method output_type
-	4, // [4:6] is the sub-list for method input_type
-	4, // [4:4] is the sub-list for extension type_name
-	4, // [4:4] is the sub-list for extension extendee
-	0, // [0:4] is the sub-list for field type_name
+	6, // 0: sink.v1.SinkRequest.event_time:type_name -> google.protobuf.Timestamp
+	6, // 1: sink.v1.SinkRequest.watermark:type_name -> google.protobuf.Timestamp
+	4, // 2: sink.v1.SinkRequest.headers:type_name -> sink.v1.SinkRequest.HeadersEntry
+	5, // 3: sink.v1.SinkResponse.results:type_name -> sink.v1.SinkResponse.Result
+	0, // 4: sink.v1.SinkResponse.Result.status:type_name -> sink.v1.Status
+	1, // 5: sink.v1.Sink.SinkFn:input_type -> sink.v1.SinkRequest
+	7, // 6: sink.v1.Sink.IsReady:input_type -> google.protobuf.Empty
+	3, // 7: sink.v1.Sink.SinkFn:output_type -> sink.v1.SinkResponse
+	2, // 8: sink.v1.Sink.IsReady:output_type -> sink.v1.ReadyResponse
+	7, // [7:9] is the sub-list for method output_type
+	5, // [5:7] is the sub-list for method input_type
+	5, // [5:5] is the sub-list for extension type_name
+	5, // [5:5] is the sub-list for extension extendee
+	0, // [0:5] is the sub-list for field type_name
 }
 
 func init() { file_pkg_apis_proto_sink_v1_sink_proto_init() }
@@ -428,13 +485,14 @@ func file_pkg_apis_proto_sink_v1_sink_proto_init() {
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_pkg_apis_proto_sink_v1_sink_proto_rawDesc,
-			NumEnums:      0,
+			NumEnums:      1,
 			NumMessages:   5,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
 		GoTypes:           file_pkg_apis_proto_sink_v1_sink_proto_goTypes,
 		DependencyIndexes: file_pkg_apis_proto_sink_v1_sink_proto_depIdxs,
+		EnumInfos:         file_pkg_apis_proto_sink_v1_sink_proto_enumTypes,
 		MessageInfos:      file_pkg_apis_proto_sink_v1_sink_proto_msgTypes,
 	}.Build()
 	File_pkg_apis_proto_sink_v1_sink_proto = out.File
diff --git a/pkg/apis/proto/sink/v1/sink.proto b/pkg/apis/proto/sink/v1/sink.proto
index 5e47fe4c..0bdd5a27 100644
--- a/pkg/apis/proto/sink/v1/sink.proto
+++ b/pkg/apis/proto/sink/v1/sink.proto
@@ -35,6 +35,15 @@ message ReadyResponse {
   bool ready = 1;
 }
 
+/*
+  * Status is the status of the response.
+ */
+enum Status {
+  SUCCESS = 0;
+  FAILURE = 1;
+  FALLBACK = 2;
+}
+
 /**
  * SinkResponse is the individual response of each message written to the sink.
  */
@@ -42,8 +51,8 @@ message SinkResponse {
   message Result {
     // id is the ID of the message, can be used to uniquely identify the message.
     string id = 1;
-    // success denotes the status of persisting to disk. if set to false, it means writing to sink for the message failed.
-    bool success = 2;
+    // status denotes the status of persisting to sink. It can be SUCCESS, FAILURE, or FALLBACK.
+    Status status = 2;
     // err_msg is the error message, set it if success is set to false.
     string err_msg = 3;
   }
diff --git a/pkg/apis/proto/source/v1/source.pb.go b/pkg/apis/proto/source/v1/source.pb.go
index 1304f4ee..7927e25e 100644
--- a/pkg/apis/proto/source/v1/source.pb.go
+++ b/pkg/apis/proto/source/v1/source.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/source/v1/source.proto
 
diff --git a/pkg/apis/proto/sourcetransform/v1/transform.pb.go b/pkg/apis/proto/sourcetransform/v1/transform.pb.go
index 3a34e351..b56efc20 100644
--- a/pkg/apis/proto/sourcetransform/v1/transform.pb.go
+++ b/pkg/apis/proto/sourcetransform/v1/transform.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
-// 	protoc-gen-go v1.28.1
+// 	protoc-gen-go v1.33.0
 // 	protoc        v4.25.1
 // source: pkg/apis/proto/sourcetransform/v1/transform.proto
 
diff --git a/pkg/sinker/examples/log/Makefile b/pkg/sinker/examples/log/Makefile
index 0850b8dc..e94cbff6 100644
--- a/pkg/sinker/examples/log/Makefile
+++ b/pkg/sinker/examples/log/Makefile
@@ -10,7 +10,7 @@ image-push: build
 	docker buildx build -t "quay.io/numaio/numaflow-go/sink-log:${TAG}" --platform linux/amd64,linux/arm64 --target log . --push
 
 .PHONY: image
-imageimage: build
+image: build
 	docker build -t "quay.io/numaio/numaflow-go/sink-log:${TAG}" --target log .
 	@if [ "$(PUSH)" = "true" ]; then docker push "quay.io/numaio/numaflow-go/sink-log:${TAG}"; fi
 
diff --git a/pkg/sinker/examples/log/main.go b/pkg/sinker/examples/log/main.go
index 89f18a76..1f7c1156 100644
--- a/pkg/sinker/examples/log/main.go
+++ b/pkg/sinker/examples/log/main.go
@@ -20,6 +20,8 @@ func (l *logSink) Sink(ctx context.Context, datumStreamCh <-chan sinksdk.Datum)
 		fmt.Println("User Defined Sink:", string(d.Value()))
 		id := d.ID()
 		result = result.Append(sinksdk.ResponseOK(id))
+		// if we are not able to write to sink and if we have a fallback sink configured
+		// we can use sinksdk.ResponseFallback(id)) to write the message to fallback sink
 	}
 	return result
 }
diff --git a/pkg/sinker/options.go b/pkg/sinker/options.go
index a913ae8b..361cc2e5 100644
--- a/pkg/sinker/options.go
+++ b/pkg/sinker/options.go
@@ -1,5 +1,7 @@
 package sinker
 
+import "os"
+
 type options struct {
 	sockAddr           string
 	maxMessageSize     int
@@ -10,10 +12,19 @@ type options struct {
 type Option func(*options)
 
 func defaultOptions() *options {
+	defaultPath := serverInfoFilePath
+	defaultAddress := address
+
+	// If the container type is fallback sink, then use the fallback sink address and path.
+	if os.Getenv(EnvUDContainerType) == UDContainerFallbackSink {
+		defaultPath = fbServerInfoFilePath
+		defaultAddress = fbAddress
+	}
+
 	return &options{
-		sockAddr:           address,
+		sockAddr:           defaultAddress,
 		maxMessageSize:     defaultMaxMessageSize,
-		serverInfoFilePath: serverInfoFilePath,
+		serverInfoFilePath: defaultPath,
 	}
 }
 
diff --git a/pkg/sinker/service.go b/pkg/sinker/service.go
index 4ac48c15..67f99838 100644
--- a/pkg/sinker/service.go
+++ b/pkg/sinker/service.go
@@ -12,10 +12,14 @@ import (
 )
 
 const (
-	uds                   = "unix"
-	defaultMaxMessageSize = 1024 * 1024 * 64 // 64MB
-	address               = "/var/run/numaflow/sink.sock"
-	serverInfoFilePath    = "/var/run/numaflow/sinker-server-info"
+	uds                     = "unix"
+	defaultMaxMessageSize   = 1024 * 1024 * 64 // 64MB
+	address                 = "/var/run/numaflow/sink.sock"
+	fbAddress               = "/var/run/numaflow/fb-sink.sock"
+	serverInfoFilePath      = "/var/run/numaflow/sinker-server-info"
+	fbServerInfoFilePath    = "/var/run/numaflow/fb-sinker-server-info"
+	EnvUDContainerType      = "NUMAFLOW_UD_CONTAINER_TYPE"
+	UDContainerFallbackSink = "fb-udsink"
 )
 
 // handlerDatum implements the Datum interface and is used in the sink functions.
@@ -78,11 +82,23 @@ func (fs *Service) SinkFn(stream sinkpb.Sink_SinkFnServer) error {
 		defer wg.Done()
 		messages := fs.Sinker.Sink(ctx, datumStreamCh)
 		for _, msg := range messages {
-			resultList = append(resultList, &sinkpb.SinkResponse_Result{
-				Id:      msg.ID,
-				Success: msg.Success,
-				ErrMsg:  msg.Err,
-			})
+			if msg.Fallback {
+				resultList = append(resultList, &sinkpb.SinkResponse_Result{
+					Id:     msg.ID,
+					Status: sinkpb.Status_FALLBACK,
+				})
+			} else if msg.Success {
+				resultList = append(resultList, &sinkpb.SinkResponse_Result{
+					Id:     msg.ID,
+					Status: sinkpb.Status_SUCCESS,
+				})
+			} else {
+				resultList = append(resultList, &sinkpb.SinkResponse_Result{
+					Id:     msg.ID,
+					Status: sinkpb.Status_FAILURE,
+					ErrMsg: msg.Err,
+				})
+			}
 		}
 	}()
 
diff --git a/pkg/sinker/service_test.go b/pkg/sinker/service_test.go
index 176499a6..d6ad1b5b 100644
--- a/pkg/sinker/service_test.go
+++ b/pkg/sinker/service_test.go
@@ -86,19 +86,19 @@ func TestService_SinkFn(t *testing.T) {
 			}),
 			expected: []*sinkpb.SinkResponse_Result{
 				{
-					Success: true,
-					Id:      "one-processed",
-					ErrMsg:  "",
+					Status: sinkpb.Status_SUCCESS,
+					Id:     "one-processed",
+					ErrMsg: "",
 				},
 				{
-					Success: true,
-					Id:      "two-processed",
-					ErrMsg:  "",
+					Status: sinkpb.Status_SUCCESS,
+					Id:     "two-processed",
+					ErrMsg: "",
 				},
 				{
-					Success: true,
-					Id:      "three-processed",
-					ErrMsg:  "",
+					Status: sinkpb.Status_SUCCESS,
+					Id:     "three-processed",
+					ErrMsg: "",
 				},
 			},
 		},
@@ -140,19 +140,19 @@ func TestService_SinkFn(t *testing.T) {
 			}),
 			expected: []*sinkpb.SinkResponse_Result{
 				{
-					Success: false,
-					Id:      "one-processed",
-					ErrMsg:  "unknown error",
+					Status: sinkpb.Status_FAILURE,
+					Id:     "one-processed",
+					ErrMsg: "unknown error",
 				},
 				{
-					Success: false,
-					Id:      "two-processed",
-					ErrMsg:  "unknown error",
+					Status: sinkpb.Status_FAILURE,
+					Id:     "two-processed",
+					ErrMsg: "unknown error",
 				},
 				{
-					Success: false,
-					Id:      "three-processed",
-					ErrMsg:  "unknown error",
+					Status: sinkpb.Status_FAILURE,
+					Id:     "three-processed",
+					ErrMsg: "unknown error",
 				},
 			},
 		},
diff --git a/pkg/sinker/types.go b/pkg/sinker/types.go
index 3b33f47b..125b914c 100644
--- a/pkg/sinker/types.go
+++ b/pkg/sinker/types.go
@@ -8,6 +8,8 @@ type Response struct {
 	Success bool `json:"success"`
 	// Err represents the error message when "success" is false.
 	Err string `json:"err,omitempty"`
+	// Fallback is true if the message to be sent to the fallback sink.
+	Fallback bool `json:"fallback,omitempty"`
 }
 
 type Responses []Response
@@ -28,10 +30,20 @@ func (r Responses) Items() []Response {
 	return r
 }
 
+// ResponseOK creates a successful Response with the given id.
+// The Success field is set to true.
 func ResponseOK(id string) Response {
 	return Response{ID: id, Success: true}
 }
 
+// ResponseFailure creates a failed Response with the given id and error message.
+// The Success field is set to false and the Err field is set to the provided error message.
 func ResponseFailure(id, errMsg string) Response {
 	return Response{ID: id, Success: false, Err: errMsg}
 }
+
+// ResponseFallback creates a Response with the Fallback field set to true.
+// This indicates that the message should be sent to the fallback sink.
+func ResponseFallback(id string) Response {
+	return Response{ID: id, Fallback: true}
+}