v9.0.0-rc.2

9.0.0-rc.2 (2026-04-09)

⚠ BREAKING CHANGES

• Metrics system replaced: OpenCensus has been replaced with OpenTelemetry. Direct integrations for Datadog, Stackdriver, and Prometheus have been removed. Config sections [Datadog], [Stackdriver], [Prometheus] and their environment variables (USE_DATADOG, USE_STACKDRIVER, USE_PROMETHEUS, DATADOG_*, STACKDRIVER_*, PROMETHEUS_*) are no longer supported. Use the new [OpenTelemetry] config section with USE_OTLP, OTEL_SERVICE_NAME, OTEL_EXPORTER_OTLP_ENDPOINT, OTEL_EXPORTER_OTLP_PROTOCOL, and OTEL_EXPORTER_OTLP_HEADERS to export metrics via OTLP to any compatible backend.
• Metric names changed to follow OTEL semantic conventions: connections is now http.server.active_requests, newconnections has been removed, and requests has been replaced by the http.server.request.duration histogram.
• Metric attribute names changed: relayId is now relay.id, platformCategory is now platform.category, userAgent is now user_agent, sdkWrapper is now sdk.wrapper, env is now environment.name, route is now http.route, method is now http.request.method. New attributes added: url.scheme, application.id, application.version, instance.id.
• Module path changed from ld-relay/v8 to ld-relay/v9.
• Minimum Go version bumped from 1.24 to 1.25.

Features

• Add FDv2 client-side streaming and polling support for mobile and JS client SDKs
• Add http.server.request.duration histogram metric with per-endpoint granularity, response status codes, and protocol version attributes
• Add event processing OTEL metrics for ingestion, forwarding, errors, drops, and queue depth
• Add OTLP metrics export support via gRPC or HTTP to any compatible backend

Bug Fixes

• deps: bump google.golang.org/grpc from 1.61.0 to 1.79.3
• deps: bump supported Go versions to 1.26.2 and 1.25.9
• deps: update Dockerfiles from 3.23.2 to alpine:3.23.3