OpenTelemetry .NET SDK Unlocks Parallel OTLP and Prometheus Dual-Exporting

The OpenTelemetry project has published official guidance detailing dual-export capabilities in the OpenTelemetry .NET SDK, enabling .NET applications to push metrics via the OpenTelemetry Protocol (OTLP) while simultaneously serving scrape endpoints for Prometheus collectors. By configuring the OpenTelemetry .NET SDK with both `AddOtlpExporter()` and `AddPrometheusExporter()` on the `MeterProviderBuilder`, developers can rely purely on standard .NET `System.Diagnostics.Metrics` primitives (`Counter`, `Gauge`, and `Histogram`) rather than binding application logic directly to vendor-specific or standalone Prometheus client libraries. This pattern addresses a longstanding operational bottleneck for platform teams: migrating production observability stacks. Traditionally, transitioning an enterprise telemetry pipeline from pull-based Prometheus scraping to an OTLP-native architecture required either duplicate instrumentations or high-risk cutover windows. Dual-exporting allows teams to run both telemetry pathways in parallel with minimal runtime overhead. Site reliability engineers can maintain established Prometheus alerts and Grafana dashboards while evaluating or standing up OTLP-compatible backends like SigNoz, Honeycomb, Tempo, or managed cloud collectors. This release reflects a broader standardization across the cloud-native ecosystem following OpenTelemetry's CNCF graduation. As organizations consolidate fragmented monitoring stacks across logs, traces, and metrics, interoperability mechanisms have become central to adoption strategies. Rather than forcing teams to choose between Prometheus pull architectures and OTLP push pipelines, the OpenTelemetry Collector and language SDKs are increasingly acting as universal ingestion and routing layers. Prometheus's own opt-in support for pushed OTLP payloads (`--web.enable-otlp-receiver`) further solidifies OTLP as the default wire format across heterogeneous environments. In practice, developers adopting this pattern must account for architectural nuances between the systems. In ASP.NET Core environments, registering `AddPrometheusExporter()` wires the pipeline internally, but teams must explicitly map the endpoint using `app.MapPrometheusScrapingEndpoint()` to serve `/metrics` requests. Additionally, practitioners must recognize format boundary limits: Prometheus summary types and native exponential histograms do not map directly from standard .NET Meter instruments, meaning legacy dashboards relying on specific Prometheus-native summary representations will require query refactoring before deprecating native scrape targets.