Getting Started (ASP.NET Core)

Configuration

In order to add the Server Timing API support to an application a required service and middleware must be registered. The library provides extensions which make it really simple.

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        ...

        services.AddServerTiming();

        ...
    }

    public void Configure(IApplicationBuilder app)
    {
        ...

        app.UseServerTiming();

        ...
    }
}

Options can be set when registering the middleware - e.g. to set URLs that are allowed to see values from timing APIs (which would otherwise be reported as zero due to cross-origin restrictions), or to only send timings in a development environment.

public class Startup
{
    ...

    public void Configure(IApplicationBuilder app, IHostEnvironment env)
    {
        ...

        app.UseServerTiming(options => {
            options.AllowedOrigins.Add("https://tpeczek.com");
            options.AllowedOrigins.Add("https://developer.tpeczek.com");
            options.RestrictToDevelopment(env)
        }

        ...
    }
}

Adding Metrics

In order to add timing metrics values for current request the instance of the IServerTiming service should be obtained (it's a scoped service). Once that is done, the values can simply be added to metrics collection.

serverTiming.Metrics.Add(new ServerTimingMetric("cache", 300, "Cache"));
serverTiming.Metrics.Add(new ServerTimingMetric("sql", 900, "Sql Server"));
serverTiming.Metrics.Add(new ServerTimingMetric("fs", 600, "FileSystem"));
serverTiming.Metrics.Add(new ServerTimingMetric("cpu", 1230, "Total CPU"));

The values will be available in Server-Timing header, which browsers can visualise.