Metrics: Replace <string, string> labels with attributes (open-teleme…

…try#283)

Signed-off-by: Bogdan Drutu <[email protected]>

CHANGELOG.md

@@ -29,6 +29,8 @@ Full list of differences found in [this compare.](https://github.com/open-teleme
 * :stop_sign: [DEPRECATION] Deprecate IntSum, IntGauge, and IntDataPoint (#278)
 * :stop_sign: [DEPRECATION] Deprecate IntExemplar (#281)
 * :stop_sign: [DEPRECATION] Deprecate IntHistogram (#270)
+* :stop_sign: [BREAKING] Deprecate `labels` field from NumberDataPoint, HistogramDataPoint, SummaryDataPoint and add equivalent `attributes` field (#283)
+* :stop_sign: [BREAKING] Deprecate `filtered_labels` field from Exemplars and add equivalent `filtered_attributes` field (#283)
 * :stop_sign: [BREAKING] Rename DoubleGauge to Gauge (#278)
 * :stop_sign: [BREAKING] Rename DoubleSum to Sum (#278)
 * :stop_sign: [BREAKING] Rename DoubleDataPoint to NumberDataPoint (#278)

opentelemetry/proto/common/v1/common.proto

@@ -65,6 +65,8 @@ message KeyValue {
 // StringKeyValue is a pair of key/value strings. This is the simpler (and faster) version
 // of KeyValue that only supports string values.
 message StringKeyValue {
+  option deprecated = true;
+
   string key = 1;
   string value = 2;
 }

opentelemetry/proto/metrics/v1/metrics.proto

@@ -350,8 +350,19 @@ message IntDataPoint {
 // NumberDataPoint is a single data point in a timeseries that describes the
 // time-varying value of a double metric.
 message NumberDataPoint {
-  // The set of labels that uniquely identify this timeseries.
-  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1;
+  // The set of key/value pairs that uniquely identify the timeseries from 
+  // where this point belongs. The list may be empty (may contain 0 elements).
+  repeated opentelemetry.proto.common.v1.KeyValue attributes = 7;
+
+  // Labels is deprecated and will be removed soon.
+  // 1. Old senders and receivers that are not aware of this change will
+  // continue using the `labels` field.
+  // 2. New senders, which are aware of this change MUST send only `attributes`.
+  // 3. New receivers, which are aware of this change MUST convert this into
+  // `labels` by simply converting all int64 values into float.
+  //
+  // This field will be removed in ~3 months, on July 1, 2021.
+  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1 [deprecated = true];
 
   // start_time_unix_nano is the last time when the aggregation value was reset
   // to "zero". For some metric types this is ignored, see data types for more
@@ -474,8 +485,19 @@ message IntHistogramDataPoint {
 // "explicit_bounds" and "bucket_counts" must be omitted and only "count" and
 // "sum" are known.
 message HistogramDataPoint {
-  // The set of labels that uniquely identify this timeseries.
-  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1;
+  // The set of key/value pairs that uniquely identify the timeseries from 
+  // where this point belongs. The list may be empty (may contain 0 elements).
+  repeated opentelemetry.proto.common.v1.KeyValue attributes = 9;
+
+  // Labels is deprecated and will be removed soon.
+  // 1. Old senders and receivers that are not aware of this change will
+  // continue using the `labels` field.
+  // 2. New senders, which are aware of this change MUST send only `attributes`.
+  // 3. New receivers, which are aware of this change MUST convert this into
+  // `labels` by simply converting all int64 values into float.
+  //
+  // This field will be removed in ~3 months, on July 1, 2021.
+  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1 [deprecated = true];
 
   // start_time_unix_nano is the last time when the aggregation value was reset
   // to "zero". For some metric types this is ignored, see data types for more
@@ -540,8 +562,19 @@ message HistogramDataPoint {
 // SummaryDataPoint is a single data point in a timeseries that describes the
 // time-varying values of a Summary metric.
 message SummaryDataPoint {
-  // The set of labels that uniquely identify this timeseries.
-  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1;
+  // The set of key/value pairs that uniquely identify the timeseries from 
+  // where this point belongs. The list may be empty (may contain 0 elements).
+  repeated opentelemetry.proto.common.v1.KeyValue attributes = 7;
+
+  // Labels is deprecated and will be removed soon.
+  // 1. Old senders and receivers that are not aware of this change will
+  // continue using the `labels` field.
+  // 2. New senders, which are aware of this change MUST send only `attributes`.
+  // 3. New receivers, which are aware of this change MUST convert this into
+  // `labels` by simply converting all int64 values into float.
+  //
+  // This field will be removed in ~3 months, on July 1, 2021.
+  repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1 [deprecated = true];
 
   // start_time_unix_nano is the last time when the aggregation value was reset
   // to "zero". For some metric types this is ignored, see data types for more
@@ -629,10 +662,21 @@ message IntExemplar {
 // was recorded, for example the span and trace ID of the active span when the
 // exemplar was recorded.
 message Exemplar {
-  // The set of labels that were filtered out by the aggregator, but recorded
-  // alongside the original measurement. Only labels that were filtered out
-  // by the aggregator should be included
-  repeated opentelemetry.proto.common.v1.StringKeyValue filtered_labels = 1;
+  // The set of key/value pairs that were filtered out by the aggregator, but
+  // recorded alongside the original measurement. Only key/value pairs that were
+  // filtered out by the aggregator should be included
+  repeated opentelemetry.proto.common.v1.KeyValue filtered_attributes = 7;
+
+  // Labels is deprecated and will be removed soon.
+  // 1. Old senders and receivers that are not aware of this change will
+  // continue using the `filtered_labels` field.
+  // 2. New senders, which are aware of this change MUST send only
+  // `filtered_attributes`.
+  // 3. New receivers, which are aware of this change MUST convert this into
+  // `filtered_labels` by simply converting all int64 values into float.
+  //
+  // This field will be removed in ~3 months, on July 1, 2021.
+  repeated opentelemetry.proto.common.v1.StringKeyValue filtered_labels = 1 [deprecated = true];
 
   // time_unix_nano is the exact time when this exemplar was recorded
   //