Fix sampleRate in AppInsightsSampler (#26771)

Author: lzchen

sdk/monitor/azure-monitor-opentelemetry-exporter/CHANGELOG.md

@@ -11,6 +11,9 @@
 
 ### Bugs Fixed
 
+- Fixed sampleRate field in ApplicationInsightsSampler, changed attribute to `_MS.sampleRate`
+    ([#26771](https://github.com/Azure/azure-sdk-for-python/pull/26771))
+
 ### Other Changes
 
 - Update `README.md`

sdk/monitor/azure-monitor-opentelemetry-exporter/azure/monitor/opentelemetry/exporter/_constants.py

@@ -98,3 +98,7 @@
 ]
 # cSpell:enable
 _INSTRUMENTATIONS_BIT_MAP = {_INSTRUMENTATIONS_LIST[i]: _BASE**i for i in range(len(_INSTRUMENTATIONS_LIST))}
+
+# sampleRate
+
+_SAMPLE_RATE_KEY = "_MS.sampleRate"

sdk/monitor/azure-monitor-opentelemetry-exporter/azure/monitor/opentelemetry/exporter/export/_base.py

@@ -58,6 +58,9 @@ def __init__(self, **kwargs: Any) -> None:
         """Azure Monitor base exporter for OpenTelemetry.
 
         :keyword str api_version: The service API version used. Defaults to latest.
+        :keyword str connection_string: The connection string used for your Application Insights resource.
+        :keyword bool enable_local_storage: Determines whether to store failed telemetry records for retry. Defaults to `True`.
+        :keyword str storage_path: Storage path in which to store retry files. Defaults to `<tempfile.gettempdir()>/opentelemetry-python-<your-instrumentation-key>`.
         :rtype: None
         """
         parsed_connection_string = ConnectionStringParser(kwargs.get('connection_string'))

sdk/monitor/azure-monitor-opentelemetry-exporter/azure/monitor/opentelemetry/exporter/export/trace/_exporter.py

@@ -11,6 +11,7 @@
 from opentelemetry.sdk.trace.export import SpanExporter, SpanExportResult
 from opentelemetry.trace import SpanKind
 
+from azure.monitor.opentelemetry.exporter._constants import _SAMPLE_RATE_KEY
 from azure.monitor.opentelemetry.exporter import _utils
 from azure.monitor.opentelemetry.exporter._generated.models import (
     MessageData,
@@ -45,6 +46,10 @@
     "code.",
 ]
 
+_STANDARD_AZURE_MONITOR_ATTRIBUTES = [
+    _SAMPLE_RATE_KEY,
+]
+
 
 class AzureMonitorTraceExporter(BaseExporter, SpanExporter):
     """Azure Monitor Trace exporter for OpenTelemetry."""
@@ -420,9 +425,13 @@ def _convert_span_to_envelope(span: ReadableSpan) -> TelemetryItem:
         if target:
             data.target = str(target)[:1024]
 
+    # sampleRate
+    if _SAMPLE_RATE_KEY in span.attributes:
+        envelope.sample_rate = span.attributes[_SAMPLE_RATE_KEY]
+
     data.properties = _utils._filter_custom_properties(
         span.attributes,
-        lambda key, val: not _is_opentelemetry_standard_attribute(key)
+        lambda key, val: not _is_standard_attribute(key)
     )
     if span.links:
         # Max length for value is 8192
@@ -450,7 +459,7 @@ def _convert_span_events_to_envelopes(span: ReadableSpan) -> Sequence[TelemetryI
             )
         properties = _utils._filter_custom_properties(
             event.attributes,
-            lambda key, val: not _is_opentelemetry_standard_attribute(key)
+            lambda key, val: not _is_standard_attribute(key)
         )
         if event.name == "exception":
             envelope.name = 'Microsoft.ApplicationInsights.Exception'
@@ -545,11 +554,12 @@ def _check_instrumentation_span(span: ReadableSpan) -> None:
         _utils.add_instrumentation(name)
 
 
-def _is_opentelemetry_standard_attribute(key: str) -> bool:
+def _is_standard_attribute(key: str) -> bool:
     for prefix in _STANDARD_OPENTELEMETRY_ATTRIBUTE_PREFIXES:
         if key.startswith(prefix):
             return True
-    return False
+    return key in _STANDARD_AZURE_MONITOR_ATTRIBUTES
+
 
 def _get_azure_sdk_target_source(attributes: Attributes) -> Optional[str]:
     # Currently logic only works for ServiceBus and EventHub

sdk/monitor/azure-monitor-opentelemetry-exporter/azure/monitor/opentelemetry/exporter/export/trace/_sampling.py

@@ -15,6 +15,8 @@
 from opentelemetry.trace.span import TraceState
 from opentelemetry.util.types import Attributes
 
+from azure.monitor.opentelemetry.exporter._constants import _SAMPLE_RATE_KEY
+
 
 _HASH = 5381
 _INTEGER_MAX = Int32.maxval
@@ -62,7 +64,7 @@ def should_sample(
         # Add sample rate as span attribute
         if attributes is None:
             attributes = {}
-        attributes["sampleRate"] = self._sample_rate
+        attributes[_SAMPLE_RATE_KEY] = self._sample_rate
         return SamplingResult(
             decision,
             attributes,

sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/README.md

@@ -10,7 +10,9 @@ products:
 
 These code samples show common champion scenario operations with the AzureMonitorMetricExporter.
 
+* Attributes: [sample_attributes.py](https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/sample_attributes.py)
 * Instruments: [sample_instruments.py](https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/sample_instruments.py)
+* Views: [sample_views.py](https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/sample_views.py)
 
 ## Installation
 
@@ -20,6 +22,17 @@ $ pip install azure-monitor-opentelemetry-exporter --pre
 
 ## Run the Applications
 
+### Metrics with attributes
+
+* Update `APPLICATIONINSIGHTS_CONNECTION_STRING` environment variable
+
+* Run the sample
+
+```sh
+$ # from this directory
+$ python sample_attributes.py
+```
+
 ### Instrument usage
 
 * Update `APPLICATIONINSIGHTS_CONNECTION_STRING` environment variable
@@ -31,6 +44,17 @@ $ # from this directory
 $ python sample_instruments.py
 ```
 
+### Configuring metrics with views
+
+* Update `APPLICATIONINSIGHTS_CONNECTION_STRING` environment variable
+
+* Run the sample
+
+```sh
+$ # from this directory
+$ python sample_views.py
+```
+
 ## Explore the data
 
 After running the applications, data would be available in [Azure](

sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/sample_attributes.py

@@ -3,7 +3,7 @@
 """
 An example to show an application using different attributes with instruments in the OpenTelemetry SDK.
 Metrics created and recorded using the sdk are tracked and telemetry is exported to application insights
-with the AzureMonitorMetricsExporter.
+with the AzureMonitorMetricExporter.
 """
 import os
 
@@ -16,7 +16,8 @@
 exporter = AzureMonitorMetricExporter.from_connection_string(
     os.environ["APPLICATIONINSIGHTS_CONNECTION_STRING"]
 )
-reader = PeriodicExportingMetricReader(exporter, export_interval_millis=5000)
+# Metrics are reported every 1 minute
+reader = PeriodicExportingMetricReader(exporter)
 metrics.set_meter_provider(MeterProvider(metric_readers=[reader]))
 
 attribute_set1 = {

sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/sample_instruments.py

@@ -1,9 +1,10 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
+# cSpell:disable
 """
 An example to show an application using all instruments in the OpenTelemetry SDK. Metrics created
 and recorded using the sdk are tracked and telemetry is exported to application insights with the
-AzureMonitorMetricsExporter.
+AzureMonitorMetricExporter.
 """
 import os
 from typing import Iterable
@@ -18,7 +19,8 @@
 exporter = AzureMonitorMetricExporter.from_connection_string(
     os.environ["APPLICATIONINSIGHTS_CONNECTION_STRING"]
 )
-reader = PeriodicExportingMetricReader(exporter, export_interval_millis=5000)
+# Metrics are reported every 1 minute
+reader = PeriodicExportingMetricReader(exporter)
 metrics.set_meter_provider(MeterProvider(metric_readers=[reader]))
 
 # Create a namespaced meter
@@ -63,3 +65,5 @@ def observable_gauge_func(options: CallbackOptions) -> Iterable[Observation]:
 
 # Async Gauge
 gauge = meter.create_observable_gauge("gauge", [observable_gauge_func])
+
+# cSpell:disable

sdk/monitor/azure-monitor-opentelemetry-exporter/samples/metrics/sample_views.py

@@ -3,7 +3,7 @@
 """
 This example shows how to customize the metrics that are output by the SDK using Views. Metrics created
 and recorded using the sdk are tracked and telemetry is exported to application insights with the
-AzureMonitorMetricsExporter.
+AzureMonitorMetricExporter.
 """
 import os
 
@@ -25,7 +25,8 @@
     name="my.counter.total",
 )
 
-reader = PeriodicExportingMetricReader(exporter, export_interval_millis=5000)
+# Metrics are reported every 1 minute
+reader = PeriodicExportingMetricReader(exporter)
 provider = MeterProvider(
     metric_readers=[
         reader,

sdk/monitor/azure-monitor-opentelemetry-exporter/samples/traces/sample_sampling.py

@@ -29,3 +29,5 @@
     # Approximately 25% of these spans should be sampled out
     with tracer.start_as_current_span("hello"):
         print("Hello, World!")
+
+input()

sdk/monitor/azure-monitor-opentelemetry-exporter/tests/trace/test_sampling.py

@@ -1,6 +1,7 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 import unittest
+from unittest import mock
 
 from azure.monitor.opentelemetry.exporter.export.trace._sampling import (
     ApplicationInsightsSampler,
@@ -21,3 +22,19 @@ def test_invalid_ratio(self):
         self.assertRaises(
             ValueError, lambda: ApplicationInsightsSampler(-0.01)
         )
+
+    @mock.patch.object(ApplicationInsightsSampler, '_get_DJB2_sample_score')
+    def test_should_sample(self, score_mock):
+        sampler = ApplicationInsightsSampler(0.75)
+        score_mock.return_value = 0.7
+        result = sampler.should_sample(None, 0, "test")
+        self.assertEqual(result.attributes["_MS.sampleRate"], 75)
+        self.assertTrue(result.decision.is_sampled())
+
+    @mock.patch.object(ApplicationInsightsSampler, '_get_DJB2_sample_score')
+    def test_should_sample_not_sampled(self, score_mock):
+        sampler = ApplicationInsightsSampler(0.5)
+        score_mock.return_value = 0.7
+        result = sampler.should_sample(None, 0, "test")
+        self.assertEqual(result.attributes["_MS.sampleRate"], 50)
+        self.assertFalse(result.decision.is_sampled())

sdk/monitor/azure-monitor-opentelemetry-exporter/tests/trace/test_trace.py

@@ -976,6 +976,34 @@ def test_span_to_envelope_success_error(self):
         envelope = exporter._span_to_envelope(span)
         self.assertFalse(envelope.data.base_data.success)
 
+    def test_span_to_envelope_sample_rate(self):
+        exporter = self._exporter
+        start_time = 1575494316027613500
+        end_time = start_time + 1001000000
+
+        span = trace._Span(
+            name="test",
+            context=SpanContext(
+                trace_id=36873507687745823477771305566750195431,
+                span_id=12030755672171557337,
+                is_remote=False,
+            ),
+            attributes={
+                "test": "asd",
+                "http.method": "GET",
+                "http.url": "https://www.wikipedia.org/wiki/Rabbit",
+                "http.status_code": 200,
+                "_MS.sampleRate": 50,
+            },
+            kind=SpanKind.CLIENT,
+        )
+        span._status = Status(status_code=StatusCode.OK)
+        span.start(start_time=start_time)
+        span.end(end_time=end_time)
+        envelope = exporter._span_to_envelope(span)
+        self.assertEqual(envelope.sample_rate, 50)
+        self.assertIsNone(envelope.data.base_data.properties.get("_MS.sampleRate"))
+
     def test_span_to_envelope_properties(self):
         exporter = self._exporter
         start_time = 1575494316027613500