OpenTelemetry: ActivityPub federation metrics

CHANGES.md

@@ -22,10 +22,43 @@ To be released.
     and delayed counts, and `ParallelMessageQueue` delegates depth reporting
     to its wrapped queue when supported.  [[#735], [#748]]
 
+ -  Added OpenTelemetry metrics for ActivityPub delivery attempts, permanent
+    delivery failures, inbox listener processing duration, and HTTP Signature
+    verification failures.  Applications can pass the new `meterProvider`
+    option to `createFederation()`, and `Context.meterProvider` exposes the
+    provider available to request, inbox, and outbox code.
+    [[#316], [#619], [#755]]
+
+ -  Added the `activitypub.delivery.failed` span event to queued outbox
+    delivery spans so retry and permanent-failure decisions include the
+    remote host, attempt number, and HTTP status code when available.
+    [[#316], [#619], [#755]]
+
+ -  *Breaking change*: Changed the `activitypub.activity.sent` span event to
+    record delivery metadata (`activitypub.inbox.url` and
+    `activitypub.activity.id`) instead of the full `activitypub.activity.json`
+    payload.  `FedifySpanExporter` now stores outbound records from those
+    attributes, and `TraceActivityRecord.activityJson` is present only when the
+    span event includes full activity JSON.  [[#316], [#619], [#755]]
+
+[#316]: https://github.com/fedify-dev/fedify/issues/316
+[#619]: https://github.com/fedify-dev/fedify/issues/619
 [#735]: https://github.com/fedify-dev/fedify/issues/735
 [#748]: https://github.com/fedify-dev/fedify/pull/748
 [#752]: https://github.com/fedify-dev/fedify/issues/752
 [#753]: https://github.com/fedify-dev/fedify/pull/753
+[#755]: https://github.com/fedify-dev/fedify/pull/755
+
+### @fedify/fixture
+
+ -  Added `createTestMeterProvider()` and `TestMetricRecorder` helpers for
+    asserting OpenTelemetry metric measurements in runtime-agnostic tests.
+    [[#316], [#619], [#755]]
+
+### @fedify/testing
+
+ -  Added a `meterProvider` option to `createFederation()` so mock contexts can
+    expose a test OpenTelemetry meter provider.  [[#316], [#619], [#755]]
 
 ### @fedify/amqp
 

deno.json

@@ -47,6 +47,7 @@
     "@opentelemetry/api": "npm:@opentelemetry/api@^1.9.0",
     "@opentelemetry/context-async-hooks": "npm:@opentelemetry/context-async-hooks@^2.5.0",
     "@opentelemetry/core": "npm:@opentelemetry/core@^2.5.0",
+    "@opentelemetry/sdk-metrics": "npm:@opentelemetry/sdk-metrics@2.5.0",
     "@opentelemetry/sdk-trace-base": "npm:@opentelemetry/sdk-trace-base@^2.5.0",
     "@opentelemetry/semantic-conventions": "npm:@opentelemetry/semantic-conventions@^1.39.0",
     "@optique/config": "jsr:@optique/config@^1.0.2",

docs/manual/federation.md

@@ -444,6 +444,18 @@ For more information, see the [*OpenTelemetry* section](./opentelemetry.md).
 
 [`trace.getTracerProvider()`]: https://open-telemetry.github.io/opentelemetry-js/classes/_opentelemetry_api._opentelemetry_api.TraceAPI.html#gettracerprovider
 
+### `meterProvider`
+
+*This API is available since Fedify 2.3.0.*
+
+The OpenTelemetry meter provider that the `Federation` object uses to record
+Fedify metrics.  If omitted, it is configured to use the default meter provider
+(i.e., [`metrics.getMeterProvider()`]).
+
+For more information, see the [*OpenTelemetry* section](./opentelemetry.md).
+
+[`metrics.getMeterProvider()`]: https://open-telemetry.github.io/opentelemetry-js/classes/_opentelemetry_api._opentelemetry_api.MetricsAPI.html#getmeterprovider
+
 
 Builder pattern for structuring
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