diff --git a/output/cloud/expv2/pbcloud/metric.pb.go b/output/cloud/expv2/pbcloud/metric.pb.go
index 76e053b50867..6b4723554191 100644
--- a/output/cloud/expv2/pbcloud/metric.pb.go
+++ b/output/cloud/expv2/pbcloud/metric.pb.go
@@ -797,6 +797,65 @@ func (x *RateValue) GetTotalCount() uint32 {
 	return 0
 }
 
+// BucketSpan represents the consecutive and significant (non-zero) buckets.
+// The concept is imported from the Prometheus' native histogram.
+// It should simplify an eventual transition to Prometheus.
+// https://github.com/prometheus/prometheus/blob/f399f386cef3b19c48157e9678a4f50997db3f41/prompb/io/prometheus/client/metrics.proto#L115-L124
+type BucketSpan struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	Offset uint32 `protobuf:"varint,1,opt,name=offset,proto3" json:"offset,omitempty"` // Gap to previous span, or starting point for 1st span.
+	Length uint32 `protobuf:"varint,2,opt,name=length,proto3" json:"length,omitempty"` // Length of the next consecutive buckets.
+}
+
+func (x *BucketSpan) Reset() {
+	*x = BucketSpan{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_metric_proto_msgTypes[11]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *BucketSpan) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*BucketSpan) ProtoMessage() {}
+
+func (x *BucketSpan) ProtoReflect() protoreflect.Message {
+	mi := &file_metric_proto_msgTypes[11]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use BucketSpan.ProtoReflect.Descriptor instead.
+func (*BucketSpan) Descriptor() ([]byte, []int) {
+	return file_metric_proto_rawDescGZIP(), []int{11}
+}
+
+func (x *BucketSpan) GetOffset() uint32 {
+	if x != nil {
+		return x.Offset
+	}
+	return 0
+}
+
+func (x *BucketSpan) GetLength() uint32 {
+	if x != nil {
+		return x.Length
+	}
+	return 0
+}
+
 type TrendHdrValue struct {
 	state         protoimpl.MessageState
 	sizeCache     protoimpl.SizeCache
@@ -804,32 +863,31 @@ type TrendHdrValue struct {
 
 	// Required.
 	Time *timestamppb.Timestamp `protobuf:"bytes,1,opt,name=time,proto3" json:"time,omitempty"`
-	// buckets
-	Counters []uint32 `protobuf:"varint,2,rep,packed,name=counters,proto3" json:"counters,omitempty"`
-	// index of first bucket in `counters`
-	LowerCounterIndex uint32 `protobuf:"varint,3,opt,name=lower_counter_index,json=lowerCounterIndex,proto3" json:"lower_counter_index,omitempty"`
+	// positive buckets starting from bucket 1, each counter is an absolute value.
+	Counters []uint32      `protobuf:"varint,2,rep,packed,name=counters,proto3" json:"counters,omitempty"`
+	Spans    []*BucketSpan `protobuf:"bytes,3,rep,name=spans,proto3" json:"spans,omitempty"`
 	// sum of observations
-	Sum float64 `protobuf:"fixed64,4,opt,name=sum,proto3" json:"sum,omitempty"`
+	Sum float64 `protobuf:"fixed64,5,opt,name=sum,proto3" json:"sum,omitempty"`
 	// count of observations
-	Count uint32 `protobuf:"varint,5,opt,name=count,proto3" json:"count,omitempty"`
+	Count uint32 `protobuf:"varint,6,opt,name=count,proto3" json:"count,omitempty"`
 	// smallest and largest observed value
-	MinValue float64 `protobuf:"fixed64,6,opt,name=min_value,json=minValue,proto3" json:"min_value,omitempty"`
-	MaxValue float64 `protobuf:"fixed64,7,opt,name=max_value,json=maxValue,proto3" json:"max_value,omitempty"`
-	// counters for zero and infinity buckets
-	ExtraLowValuesCounter  *uint32 `protobuf:"varint,8,opt,name=extra_low_values_counter,json=extraLowValuesCounter,proto3,oneof" json:"extra_low_values_counter,omitempty"`
-	ExtraHighValuesCounter *uint32 `protobuf:"varint,9,opt,name=extra_high_values_counter,json=extraHighValuesCounter,proto3,oneof" json:"extra_high_values_counter,omitempty"`
+	MinValue float64 `protobuf:"fixed64,7,opt,name=min_value,json=minValue,proto3" json:"min_value,omitempty"`
+	MaxValue float64 `protobuf:"fixed64,8,opt,name=max_value,json=maxValue,proto3" json:"max_value,omitempty"`
+	// counters for zero- and infinity-buckets
+	ExtraLowValuesCounter  *uint32 `protobuf:"varint,9,opt,name=extra_low_values_counter,json=extraLowValuesCounter,proto3,oneof" json:"extra_low_values_counter,omitempty"`
+	ExtraHighValuesCounter *uint32 `protobuf:"varint,10,opt,name=extra_high_values_counter,json=extraHighValuesCounter,proto3,oneof" json:"extra_high_values_counter,omitempty"`
 	// histogram parameter - value multiplier aka smallest value
 	// default = 1.0
-	MinResolution *float64 `protobuf:"fixed64,10,opt,name=min_resolution,json=minResolution,proto3,oneof" json:"min_resolution,omitempty"`
+	MinResolution *float64 `protobuf:"fixed64,11,opt,name=min_resolution,json=minResolution,proto3,oneof" json:"min_resolution,omitempty"`
 	// histogram parameter - number of significant digits used to calculate buckets formula
 	// default = 2
-	SignificantDigits *uint32 `protobuf:"varint,11,opt,name=significant_digits,json=significantDigits,proto3,oneof" json:"significant_digits,omitempty"`
+	SignificantDigits *uint32 `protobuf:"varint,12,opt,name=significant_digits,json=significantDigits,proto3,oneof" json:"significant_digits,omitempty"`
 }
 
 func (x *TrendHdrValue) Reset() {
 	*x = TrendHdrValue{}
 	if protoimpl.UnsafeEnabled {
-		mi := &file_metric_proto_msgTypes[11]
+		mi := &file_metric_proto_msgTypes[12]
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		ms.StoreMessageInfo(mi)
 	}
@@ -842,7 +900,7 @@ func (x *TrendHdrValue) String() string {
 func (*TrendHdrValue) ProtoMessage() {}
 
 func (x *TrendHdrValue) ProtoReflect() protoreflect.Message {
-	mi := &file_metric_proto_msgTypes[11]
+	mi := &file_metric_proto_msgTypes[12]
 	if protoimpl.UnsafeEnabled && x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -855,7 +913,7 @@ func (x *TrendHdrValue) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use TrendHdrValue.ProtoReflect.Descriptor instead.
 func (*TrendHdrValue) Descriptor() ([]byte, []int) {
-	return file_metric_proto_rawDescGZIP(), []int{11}
+	return file_metric_proto_rawDescGZIP(), []int{12}
 }
 
 func (x *TrendHdrValue) GetTime() *timestamppb.Timestamp {
@@ -872,11 +930,11 @@ func (x *TrendHdrValue) GetCounters() []uint32 {
 	return nil
 }
 
-func (x *TrendHdrValue) GetLowerCounterIndex() uint32 {
+func (x *TrendHdrValue) GetSpans() []*BucketSpan {
 	if x != nil {
-		return x.LowerCounterIndex
+		return x.Spans
 	}
-	return 0
+	return nil
 }
 
 func (x *TrendHdrValue) GetSum() float64 {
@@ -1020,54 +1078,58 @@ var file_metric_proto_rawDesc = []byte{
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+	0x47, 0x45, 0x10, 0x02, 0x12, 0x14, 0x0a, 0x10, 0x4d, 0x45, 0x54, 0x52, 0x49, 0x43, 0x5f, 0x54,
+	0x59, 0x50, 0x45, 0x5f, 0x52, 0x41, 0x54, 0x45, 0x10, 0x03, 0x12, 0x15, 0x0a, 0x11, 0x4d, 0x45,
+	0x54, 0x52, 0x49, 0x43, 0x5f, 0x54, 0x59, 0x50, 0x45, 0x5f, 0x54, 0x52, 0x45, 0x4e, 0x44, 0x10,
+	0x04, 0x42, 0x28, 0x5a, 0x26, 0x67, 0x6f, 0x2e, 0x6b, 0x36, 0x2e, 0x69, 0x6f, 0x2f, 0x6b, 0x36,
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+	0x70, 0x76, 0x32, 0x2f, 0x70, 0x62, 0x63, 0x6c, 0x6f, 0x75, 0x64, 0x62, 0x06, 0x70, 0x72, 0x6f,
+	0x74, 0x6f, 0x33,
 }
 
 var (
@@ -1083,7 +1145,7 @@ func file_metric_proto_rawDescGZIP() []byte {
 }
 
 var file_metric_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
-var file_metric_proto_msgTypes = make([]protoimpl.MessageInfo, 12)
+var file_metric_proto_msgTypes = make([]protoimpl.MessageInfo, 13)
 var file_metric_proto_goTypes = []interface{}{
 	(MetricType)(0),               // 0: metrics.MetricType
 	(*MetricSet)(nil),             // 1: metrics.MetricSet
@@ -1097,8 +1159,9 @@ var file_metric_proto_goTypes = []interface{}{
 	(*CounterValue)(nil),          // 9: metrics.CounterValue
 	(*GaugeValue)(nil),            // 10: metrics.GaugeValue
 	(*RateValue)(nil),             // 11: metrics.RateValue
-	(*TrendHdrValue)(nil),         // 12: metrics.TrendHdrValue
-	(*timestamppb.Timestamp)(nil), // 13: google.protobuf.Timestamp
+	(*BucketSpan)(nil),            // 12: metrics.BucketSpan
+	(*TrendHdrValue)(nil),         // 13: metrics.TrendHdrValue
+	(*timestamppb.Timestamp)(nil), // 14: google.protobuf.Timestamp
 }
 var file_metric_proto_depIdxs = []int32{
 	2,  // 0: metrics.MetricSet.metrics:type_name -> metrics.Metric
@@ -1112,16 +1175,17 @@ var file_metric_proto_depIdxs = []int32{
 	9,  // 8: metrics.CounterSamples.values:type_name -> metrics.CounterValue
 	10, // 9: metrics.GaugeSamples.values:type_name -> metrics.GaugeValue
 	11, // 10: metrics.RateSamples.values:type_name -> metrics.RateValue
-	12, // 11: metrics.TrendHdrSamples.values:type_name -> metrics.TrendHdrValue
-	13, // 12: metrics.CounterValue.time:type_name -> google.protobuf.Timestamp
-	13, // 13: metrics.GaugeValue.time:type_name -> google.protobuf.Timestamp
-	13, // 14: metrics.RateValue.time:type_name -> google.protobuf.Timestamp
-	13, // 15: metrics.TrendHdrValue.time:type_name -> google.protobuf.Timestamp
-	16, // [16:16] is the sub-list for method output_type
-	16, // [16:16] is the sub-list for method input_type
-	16, // [16:16] is the sub-list for extension type_name
-	16, // [16:16] is the sub-list for extension extendee
-	0,  // [0:16] is the sub-list for field type_name
+	13, // 11: metrics.TrendHdrSamples.values:type_name -> metrics.TrendHdrValue
+	14, // 12: metrics.CounterValue.time:type_name -> google.protobuf.Timestamp
+	14, // 13: metrics.GaugeValue.time:type_name -> google.protobuf.Timestamp
+	14, // 14: metrics.RateValue.time:type_name -> google.protobuf.Timestamp
+	14, // 15: metrics.TrendHdrValue.time:type_name -> google.protobuf.Timestamp
+	12, // 16: metrics.TrendHdrValue.spans:type_name -> metrics.BucketSpan
+	17, // [17:17] is the sub-list for method output_type
+	17, // [17:17] is the sub-list for method input_type
+	17, // [17:17] is the sub-list for extension type_name
+	17, // [17:17] is the sub-list for extension extendee
+	0,  // [0:17] is the sub-list for field type_name
 }
 
 func init() { file_metric_proto_init() }
@@ -1263,6 +1327,18 @@ func file_metric_proto_init() {
 			}
 		}
 		file_metric_proto_msgTypes[11].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*BucketSpan); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_metric_proto_msgTypes[12].Exporter = func(v interface{}, i int) interface{} {
 			switch v := v.(*TrendHdrValue); i {
 			case 0:
 				return &v.state
@@ -1281,14 +1357,14 @@ func file_metric_proto_init() {
 		(*TimeSeries_RateSamples)(nil),
 		(*TimeSeries_TrendHdrSamples)(nil),
 	}
-	file_metric_proto_msgTypes[11].OneofWrappers = []interface{}{}
+	file_metric_proto_msgTypes[12].OneofWrappers = []interface{}{}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_metric_proto_rawDesc,
 			NumEnums:      1,
-			NumMessages:   12,
+			NumMessages:   13,
 			NumExtensions: 0,
 			NumServices:   0,
 		},
diff --git a/output/cloud/expv2/pbcloud/metric.proto b/output/cloud/expv2/pbcloud/metric.proto
index 6aefdc57db33..4e66cae57e3a 100644
--- a/output/cloud/expv2/pbcloud/metric.proto
+++ b/output/cloud/expv2/pbcloud/metric.proto
@@ -115,30 +115,40 @@ message RateValue {
   uint32 total_count = 3;
 }
 
+// BucketSpan represents the consecutive and significant (non-zero) buckets.
+// The concept is imported from the Prometheus' native histogram.
+// It should simplify an eventual transition to Prometheus.
+// https://github.com/prometheus/prometheus/blob/f399f386cef3b19c48157e9678a4f50997db3f41/prompb/io/prometheus/client/metrics.proto#L115-L124
+message BucketSpan {
+  uint32 offset = 1; // Gap to previous span, or starting point for 1st span.
+  uint32 length = 2; // Length of the next consecutive buckets.
+}
+
 message TrendHdrValue {
   // Required.
   google.protobuf.Timestamp time = 1;
 
-  // buckets
+  // positive buckets starting from bucket 1, each counter is an absolute value.
   repeated uint32 counters = 2;
-  // index of first bucket in `counters`
-  uint32 lower_counter_index = 3;
+  repeated BucketSpan spans = 3;
+
   // sum of observations
-  double sum = 4;
+  double sum = 5;
   // count of observations
-  uint32 count = 5;
+  uint32 count = 6;
   // smallest and largest observed value
-  double min_value = 6;
-  double max_value = 7;
+  double min_value = 7;
+  double max_value = 8;
 
-  // counters for zero and infinity buckets
-  optional uint32 extra_low_values_counter = 8;
-  optional uint32 extra_high_values_counter = 9;
+  // counters for zero- and infinity-buckets
+  optional uint32 extra_low_values_counter = 9;
+  optional uint32 extra_high_values_counter = 10;
 
   // histogram parameter - value multiplier aka smallest value
   // default = 1.0
-  optional double min_resolution = 10;
+  optional double min_resolution = 11;
+
   // histogram parameter - number of significant digits used to calculate buckets formula
   // default = 2
-  optional uint32 significant_digits = 11;
+  optional uint32 significant_digits = 12;
 }