Clean up.

examples/AspNetCore/Program.cs

@@ -40,8 +40,7 @@
     serviceVersion: Assembly.GetExecutingAssembly().GetName().Version?.ToString() ?? "unknown",
     serviceInstanceId: Environment.MachineName);
 
-// Configure OpenTelemetry tracing & metrics with auto-start using the
-// StartWithHost extension from OpenTelemetry.Extensions.Hosting.
+// Configure OpenTelemetry tracing & metrics.
 appBuilder.Services.AddOpenTelemetry()
     .ConfigureResource(configureResource)
     .WithTracing(builder =>

src/OpenTelemetry.Exporter.Jaeger/README.md

@@ -98,8 +98,7 @@ services.AddOpenTelemetry()
                 client.DefaultRequestHeaders.Add("X-MyCustomHeader", "value");
                 return client;
             };
-        }))
-    .StartWithHost();
+        }));
 ```
 
 For users using

src/OpenTelemetry.Exporter.OpenTelemetryProtocol/README.md

@@ -135,8 +135,7 @@ services.AddOpenTelemetry()
                 client.DefaultRequestHeaders.Add("X-MyCustomHeader", "value");
                 return client;
             };
-        }))
-    .StartWithHost();
+        }));
 ```
 
 For users using

src/OpenTelemetry.Exporter.Prometheus.AspNetCore/README.md

@@ -28,8 +28,7 @@ dotnet add package --prerelease OpenTelemetry.Exporter.Prometheus.AspNetCore
     ```csharp
     services.AddOpenTelemetry()
         .WithMetrics(builder => builder
-            .AddPrometheusExporter())
-        .StartWithHost();
+            .AddPrometheusExporter());
     ```
 
 * Or configure directly:

src/OpenTelemetry.Exporter.Zipkin/README.md

@@ -87,8 +87,7 @@ services.AddOpenTelemetry()
             HttpClient client = new HttpClient();
             client.DefaultRequestHeaders.Add("X-MyCustomHeader", "value");
             return client;
-        }))
-    .StartWithHost();
+        }));
 ```
 
 For users using

src/OpenTelemetry.Extensions.Hosting/README.md

@@ -21,17 +21,6 @@ and metrics (`MeterProvider`) in [ASP.NET
 
 ## Extension method reference
 
-### Current OpenTelemetry SDK v1.4.0 and newer extensions
-
-Targeting `OpenTelemetry.OpenTelemetryBuilder`:
-
-* `StartWithHost`: Registers an
-  [IHostedService](https://learn.microsoft.com/dotnet/api/microsoft.extensions.hosting.ihostedservice)
-  to automatically start tracing and/or metric services in the supplied
-  [IServiceCollection](https://learn.microsoft.com/dotnet/api/microsoft.extensions.dependencyinjection.iservicecollection).
-
-### Obsolete OpenTelemetry SDK pre-1.4.0 extensions
-
 > **Note**
 > The below extension methods should be called by application host code
 only. Library authors see: [Registration extension method guidance for library
@@ -72,10 +61,9 @@ using OpenTelemetry.Trace;
 
 var appBuilder = WebApplication.CreateBuilder(args);
 
-appBuilder.Services.AddOpenTelemetry()
-    .WithTracing(builder => builder.AddConsoleExporter())
-    .WithMetrics(builder => builder.AddConsoleExporter())
-    .StartWithHost();
+appBuilder.Services.AddOpenTelemetryTracing(builder => builder.AddConsoleExporter());
+
+appBuilder.Services.AddOpenTelemetryMetrics(builder => builder.AddConsoleExporter());
 
 var app = appBuilder.Build();
 

src/OpenTelemetry.Instrumentation.AspNetCore/README.md

@@ -58,8 +58,7 @@ public void ConfigureServices(IServiceCollection services)
     services.AddOpenTelemetry()
         .WithTracing(builder => builder
             .AddAspNetCoreInstrumentation()
-            .AddJaegerExporter())
-        .StartWithHost();
+            .AddJaegerExporter());
 }
 ```
 
@@ -88,8 +87,7 @@ services.Configure<AspNetCoreInstrumentationOptions>(options =>
 services.AddOpenTelemetry()
     .WithTracing(builder => builder
         .AddAspNetCoreInstrumentation()
-        .AddJaegerExporter())
-    .StartWithHost();
+        .AddJaegerExporter());
 ```
 
 ### Filter
@@ -112,8 +110,7 @@ services.AddOpenTelemetry()
             // only collect telemetry about HTTP GET requests
             return httpContext.Request.Method.Equals("GET");
         })
-        .AddJaegerExporter())
-    .StartWithHost();
+        .AddJaegerExporter());
 ```
 
 It is important to note that this `Filter` option is specific to this
@@ -150,8 +147,7 @@ services.AddOpenTelemetry()
             {
                 activity.SetTag("exceptionType", exception.GetType().ToString());
             };
-        }))
-    .StartWithHost();
+        }));
 ```
 
 [Processor](../../docs/trace/extending-the-sdk/README.md#processor),

src/OpenTelemetry.Instrumentation.GrpcNetClient/README.md

@@ -120,8 +120,7 @@ services.AddOpenTelemetry()
             {
                 activity.SetTag("responseVersion", httpResponseMessage.Version);
             };
-        })
-    .StartWithHost();
+        });
 ```
 
 [Processor](../../docs/trace/extending-the-sdk/README.md#processor),