opentelemetry-datadog

Released 2026-Jul-28

Added

• Added OpenTelemetry trace support
• Configurable route extraction with built-in extractors:
  • NoRouteExtractor - No route, safest for cardinality
  • PathExtractor - Uses the URL path without query params (e.g., /users/123)
  • AxumMatchedPathExtractor - Uses Axum's MatchedPath for route templates (requires axum feature)
  • FnRouteExtractor - Custom function-based extraction via with_route_extractor_fn()
• Default route extractor depends on features:
  • With axum feature: Uses AxumMatchedPathExtractor (route templates, low cardinality)
  • Without axum feature: Uses NoRouteExtractor (safest)
• If a route is extracted, the same value is used for both the http.route attribute and the tracing span name. If no route is extracted, the span name is the HTTP method only, per semantic conventions.

Changed

• BREAKING: Removed public with_meter() method. The middleware now uses global meter and tracer providers by default via opentelemetry::global::meter() and opentelemetry::global::tracer(). The with_meter() method is retained as a non-public test utility to allow injecting custom meters without relying on global state.
• BREAKING: Renamed types. Use the new names:
  • HTTPMetricsLayer → HTTPLayer
  • HTTPMetricsService → HTTPService
  • HTTPMetricsResponseFuture → ResponseFuture
  • HTTPMetricsLayerBuilder → HTTPLayerBuilder
• BREAKING: Update default http.server.request.duration histogram boundaries to OTel semantic conventions.
• BREAKING: Remove with_request_duration_bounds builder method. Alternate histogram bucket boundaries can be applied with the standard OpenTelemetry Views; see examples directory in crate for usage.

Migration Guide

Route Extraction Configuration

use opentelemetry_instrumentation_tower::{
    HTTPLayerBuilder,
    NoRouteExtractor,
    PathExtractor,
};

// No route (default without axum feature) - span name: "GET"
let layer = HTTPLayerBuilder::builder()
    .with_route_extractor(NoRouteExtractor)
    .build()
    .unwrap();

// Path (strips query params) - span name: "GET /users/123"
let layer = HTTPLayerBuilder::builder()
    .with_route_extractor(PathExtractor)
    .build()
    .unwrap();

// Custom function - return Some(route) or None for method-only
let layer = HTTPLayerBuilder::builder()
    .with_route_extractor_fn(|req: &http::Request<_>| {
        Some(req.uri().path().to_owned())
    })
    .build()
    .unwrap();

API Changes

Before:

use opentelemetry_instrumentation_tower::HTTPMetricsLayerBuilder;

let layer = HTTPMetricsLayerBuilder::builder()
.with_meter(meter)
.build()
.unwrap();

After:

use opentelemetry_instrumentation_tower::HTTPLayer;

// Set global providers
global::set_meter_provider(meter_provider);
global::set_tracer_provider(tracer_provider); // for tracing support

// Then create the layer - simple API using global providers
let layer = HTTPLayer::new();

Type Name Changes

• Replace HTTPMetricsLayerBuilder with HTTPLayerBuilder
• Replace HTTPMetricsLayer with HTTPLayer
• Replace HTTPMetricsService with HTTPService
• Replace HTTPMetricsResponseFuture with ResponseFuture

Changed

• Update to OpenTelemetry v0.31
• Migrate to use opentelemetry-semantic-conventions package for metric names and attribute keys instead of hardcoded strings
• Add dependency on otel semantic conventions crate and use constants from it instead of hardcoded attribute names. The values are unchanged
  • HTTP_SERVER_ACTIVE_REQUESTS_METRIC now uses semconv::metric::HTTP_SERVER_ACTIVE_REQUESTS
  • HTTP_SERVER_REQUEST_BODY_SIZE_METRIC now uses semconv::metric::HTTP_SERVER_REQUEST_BODY_SIZE
  • HTTP_SERVER_RESPONSE_BODY_SIZE_METRIC now uses semconv::metric::HTTP_SERVER_RESPONSE_BODY_SIZE
  • HTTP_SERVER_DURATION_METRIC now uses semconv::metric::HTTP_SERVER_REQUEST_DURATION
• Update attribute keys to use semantic conventions constants:
  • NETWORK_PROTOCOL_NAME_LABEL now uses semconv::attribute::NETWORK_PROTOCOL_NAME
  • HTTP_REQUEST_METHOD_LABEL now uses semconv::attribute::HTTP_REQUEST_METHOD
  • HTTP_ROUTE_LABEL now uses semconv::attribute::HTTP_ROUTE
  • HTTP_RESPONSE_STATUS_CODE_LABEL now uses semconv::attribute::HTTP_RESPONSE_STATUS_CODE

Added

• Add comprehensive test coverage for all HTTP server metrics with attribute validation

Initial release of OpenTelemetry Tower instrumentation middleware for HTTP metrics collection.

Added

• HTTP server metrics middleware for Tower-compatible services
• Support for Axum framework via axum feature flag
• Metrics collection for:
  • http.server.request.duration - Request duration histogram
  • http.server.active_requests - Active requests counter
  • http.server.request.body.size - Request body size histogram
  • http.server.response.body.size - Response body size histogram
• Configurable request duration histogram boundaries
• Custom request and response attribute extractors
• Automatic protocol version, HTTP method, URL scheme, and status code labeling
• Route extraction for Axum applications

Released 2026-Sep-21

• Bump OpenTelemetry dependencies to 0.33.

• Breaking: Replace UserEventsTracerProviderBuilderExt::with_user_events_exporter with a public Processor and ProcessorBuilder. The processor can now be wrapped by filtering or other custom processors before it is added to an SdkTracerProvider, and invalid configuration is returned to the caller.

• Add links field to Part B (serialized as JSON array of {toTraceId, toSpanId})

• Add statusMessage field to Part B for error spans with descriptions

• Breaking: Update well-known attribute mappings to use stable OTel semantic conventions. The Common Schema output field names are unchanged, but the OTel attribute keys that trigger the mapping have been updated:

  • db.system → db.system.name, db.name → db.namespace, db.statement → db.query.text, messaging.destination → messaging.destination.name
  • Added rpc.system.name → rpcSystem, rpc.response.status_code → rpcGrpcStatusCode

• Fix PartA.time and PartB.startTime to use UTC ISO 8601 with trailing Z instead of +00:00

Released 2026-May-13

• Bump opentelemetry and opentelemetry_sdk versions to 0.32
• Bump eventheader and eventheader_dynamic versions to 0.5.0
• Breaking UserEventsSpanExporter::shutdown now takes &self instead of &mut self, matching the upstream SpanExporter trait change in 0.32.

• Bump opentelemetry and opentelemetry_sdk versions to 0.31

Released 2025-July-24

• Add support for RoleName,RoleInstance population from Resource.
• Add mapping of well-known (OTel Semantic Conventions) attributes to PartB.
• Only export parentId field when parent span ID is valid (not INVALID).

Released 2025-May-27

• Bump opentelemetry and opentelemetry_sdk versions to 0.30

Added

• Initial Alpha implementation