Add Exponential Histogram

CHANGELOG.md

@@ -11,7 +11,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix formatting of ConsoleMetricExporter.
   ([#3197](https://github.com/open-telemetry/opentelemetry-python/pull/3197))
 
-## Version 1.16.0/0.37b0 (2023-02-17)
+- Add exponential histogram
+  ([#2964](https://github.com/open-telemetry/opentelemetry-python/pull/2964))
+
+## Version 1.16.0/0.37b0 (2023-02-15)
+
 - Change ``__all__`` to be statically defined.
   ([#3143](https://github.com/open-telemetry/opentelemetry-python/pull/3143))
 - Remove the ability to set a global metric prefix for Prometheus exporter

exporter/opentelemetry-exporter-otlp-proto-grpc/src/opentelemetry/exporter/otlp/proto/grpc/metric_exporter/__init__.py

@@ -60,6 +60,7 @@
     ResourceMetrics,
     ScopeMetrics,
     Sum,
+    ExponentialHistogram as ExponentialHistogramType,
 )
 
 _logger = getLogger(__name__)
@@ -266,6 +267,51 @@ def _translate_data(
                                 metric.data.is_monotonic
                             )
                             pb2_metric.sum.data_points.append(pt)
+
+                    elif isinstance(metric.data, ExponentialHistogramType):
+                        for data_point in metric.data.data_points:
+
+                            if data_point.positive.bucket_counts:
+                                positive = pb2.ExponentialHistogramDataPoint.Buckets(
+                                    offset=data_point.positive.offset,
+                                    bucket_counts=data_point.positive.bucket_counts,
+                                )
+                            else:
+                                positive = None
+
+                            if data_point.negative.bucket_counts:
+                                negative = pb2.ExponentialHistogramDataPoint.Buckets(
+                                    offset=data_point.negative.offset,
+                                    bucket_counts=data_point.negative.bucket_counts,
+                                )
+                            else:
+                                negative = None
+
+                            pt = pb2.ExponentialHistogramDataPoint(
+                                attributes=self._translate_attributes(
+                                    data_point.attributes
+                                ),
+                                time_unix_nano=data_point.time_unix_nano,
+                                start_time_unix_nano=(
+                                    data_point.start_time_unix_nano
+                                ),
+                                count=data_point.count,
+                                sum=data_point.sum,
+                                scale=data_point.scale,
+                                zero_count=data_point.zero_count,
+                                positive=positive,
+                                negative=negative,
+                                flags=data_point.flags,
+                                max=data_point.max,
+                                min=data_point.min,
+                            )
+                            pb2_metric.exponential_histogram.aggregation_temporality = (
+                                metric.data.aggregation_temporality
+                            )
+                            pb2_metric.exponential_histogram.data_points.append(
+                                pt
+                            )
+
                     else:
                         _logger.warning(
                             "unsupported data type %s",

exporter/opentelemetry-exporter-otlp-proto-grpc/tests/test_otlp_metrics_exporter.py

@@ -62,7 +62,14 @@
     ObservableUpDownCounter,
     UpDownCounter,
 )
-from opentelemetry.sdk.metrics.export import AggregationTemporality, Gauge
+from opentelemetry.sdk.metrics.export import AggregationTemporality, Buckets
+from opentelemetry.sdk.metrics.export import (
+    ExponentialHistogram as ExponentialHistogramType,
+)
+from opentelemetry.sdk.metrics.export import (
+    ExponentialHistogramDataPoint,
+    Gauge,
+)
 from opentelemetry.sdk.metrics.export import Histogram as HistogramType
 from opentelemetry.sdk.metrics.export import (
     HistogramDataPoint,
@@ -163,6 +170,31 @@ def setUp(self):
             ),
         )
 
+        exponential_histogram = Metric(
+            name="exponential_histogram",
+            description="description",
+            unit="unit",
+            data=ExponentialHistogramType(
+                data_points=[
+                    ExponentialHistogramDataPoint(
+                        attributes={"a": 1, "b": True},
+                        start_time_unix_nano=0,
+                        time_unix_nano=1,
+                        count=2,
+                        sum=3,
+                        scale=4,
+                        zero_count=5,
+                        positive=Buckets(offset=6, bucket_counts=[7, 8]),
+                        negative=Buckets(offset=9, bucket_counts=[10, 11]),
+                        flags=12,
+                        min=13.0,
+                        max=14.0,
+                    )
+                ],
+                aggregation_temporality=AggregationTemporality.DELTA,
+            ),
+        )
+
         self.metrics = {
             "sum_int": MetricsData(
                 resource_metrics=[
@@ -276,6 +308,28 @@ def setUp(self):
                     )
                 ]
             ),
+            "exponential_histogram": MetricsData(
+                resource_metrics=[
+                    ResourceMetrics(
+                        resource=Resource(
+                            attributes={"a": 1, "b": False},
+                            schema_url="resource_schema_url",
+                        ),
+                        scope_metrics=[
+                            ScopeMetrics(
+                                scope=SDKInstrumentationScope(
+                                    name="first_name",
+                                    version="first_version",
+                                    schema_url="insrumentation_scope_schema_url",
+                                ),
+                                metrics=[exponential_histogram],
+                                schema_url="instrumentation_scope_schema_url",
+                            )
+                        ],
+                        schema_url="resource_schema_url",
+                    )
+                ]
+            ),
         }
 
         self.multiple_scope_histogram = MetricsData(
@@ -896,6 +950,80 @@ def test_translate_histogram(self):
         actual = self.exporter._translate_data(self.metrics["histogram"])
         self.assertEqual(expected, actual)
 
+    def test_translate_exponential_histogram(self):
+        expected = ExportMetricsServiceRequest(
+            resource_metrics=[
+                pb2.ResourceMetrics(
+                    resource=OTLPResource(
+                        attributes=[
+                            KeyValue(key="a", value=AnyValue(int_value=1)),
+                            KeyValue(
+                                key="b", value=AnyValue(bool_value=False)
+                            ),
+                        ]
+                    ),
+                    scope_metrics=[
+                        pb2.ScopeMetrics(
+                            scope=InstrumentationScope(
+                                name="first_name", version="first_version"
+                            ),
+                            metrics=[
+                                pb2.Metric(
+                                    name="exponential_histogram",
+                                    unit="unit",
+                                    description="description",
+                                    exponential_histogram=pb2.ExponentialHistogram(
+                                        data_points=[
+                                            pb2.ExponentialHistogramDataPoint(
+                                                attributes=[
+                                                    KeyValue(
+                                                        key="a",
+                                                        value=AnyValue(
+                                                            int_value=1
+                                                        ),
+                                                    ),
+                                                    KeyValue(
+                                                        key="b",
+                                                        value=AnyValue(
+                                                            bool_value=True
+                                                        ),
+                                                    ),
+                                                ],
+                                                start_time_unix_nano=0,
+                                                time_unix_nano=1,
+                                                count=2,
+                                                sum=3,
+                                                scale=4,
+                                                zero_count=5,
+                                                positive=pb2.ExponentialHistogramDataPoint.Buckets(
+                                                    offset=6,
+                                                    bucket_counts=[7, 8],
+                                                ),
+                                                negative=pb2.ExponentialHistogramDataPoint.Buckets(
+                                                    offset=9,
+                                                    bucket_counts=[10, 11],
+                                                ),
+                                                flags=12,
+                                                exemplars=[],
+                                                min=13.0,
+                                                max=14.0,
+                                            )
+                                        ],
+                                        aggregation_temporality=AggregationTemporality.DELTA,
+                                    ),
+                                )
+                            ],
+                        )
+                    ],
+                )
+            ]
+        )
+        # pylint: disable=protected-access
+        actual = self.exporter._translate_data(
+            self.metrics["exponential_histogram"]
+        )
+        self.assertEqual(expected, actual)
+
     def test_translate_multiple_scope_histogram(self):
         expected = ExportMetricsServiceRequest(
             resource_metrics=[