Metrics report diagnostics about your app. .NET 8 adds over a dozen useful metrics to ASP.NET Core, including HTTP request counts and duration, number of active HTTP requests, route matching results, rate limiting lease and queue durations, SignalR transport usage, low-level connection and TLS usage from Kestrel, error handling diagnostics, and more. Metrics are numerical measurements reported over time and can be exported to telemetry stores like Prometheus or Azure Monitor. They are useful for monitoring app health and activity, displaying graphs on a dashboard, triggering alerts in real-time, and more. ASP.NET Cores built-in metrics are automatically recorded and can be used with the .NET Aspire dashboard, an opinionated stack for building observable, distributed applications.
