Attempt to reduce provider lifetime issues (#2848)

docs/metrics/customizing-the-sdk/README.md

@@ -31,6 +31,16 @@ using OpenTelemetry.Metrics;
 using var meterProvider = Sdk.CreateMeterProviderBuilder().Build();
 ```
 
+In a typical application, a single `MeterProvider` is created at application
+startup and disposed at application shutdown. It is important to ensure that the
+provider is not disposed too early. Actual mechanism depends on the application
+type. For example, in a typical ASP.NET application, `MeterProvider` is created
+in `Application_Start`, and disposed in `Application_End` (both methods part of
+Global.asax.cs file) as shown [here](../../../examples/AspNet/Global.asax.cs). In
+a typical ASP.NET Core application, `MeterProvider` lifetime is managed by
+leveraging the built-in Dependency Injection container as shown
+[here](../../../examples/AspNetCore/Startup.cs).
+
 ## MeterProvider configuration
 
 `MeterProvider` holds the metrics configuration, which includes the following:

docs/trace/customizing-the-sdk/README.md

@@ -34,6 +34,16 @@ using OpenTelemetry.Trace;
 using var tracerProvider = Sdk.CreateTracerProviderBuilder().Build();
 ```
 
+In a typical application, a single `TracerProvider` is created at application
+startup and disposed at application shutdown. It is important to ensure that the
+provider is not disposed too early. Actual mechanism depends on the application
+type. For example, in a typical ASP.NET application, `TracerProvider` is created
+in `Application_Start`, and disposed in `Application_End` (both methods part of
+Global.asax.cs file) as shown [here](../../../examples/AspNet/Global.asax.cs). In
+a typical ASP.NET Core application, `TracerProvider` lifetime is managed by
+leveraging the built-in Dependency Injection container as shown
+[here](../../../examples/AspNetCore/Startup.cs).
+
 ## TracerProvider configuration
 
 `TracerProvider` holds the tracing configuration, which includes the following:

src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs

@@ -354,6 +354,12 @@ namespace OpenTelemetry.Internal
             this.WriteEvent(36, instrumentName, reason, fix);
         }
 
+        [Event(37, Message = "'{0}' Disposed.", Level = EventLevel.Informational)]
+        public void ProviderDisposed(string providerName)
+        {
+            this.WriteEvent(37, providerName);
+        }
+
 #if DEBUG
         public class OpenTelemetryEventListener : EventListener
         {

src/OpenTelemetry/Logs/OpenTelemetryLoggerProvider.cs

@@ -133,6 +133,7 @@ namespace OpenTelemetry.Logs
                 }
 
                 this.disposed = true;
+                OpenTelemetrySdkEventSource.Log.ProviderDisposed(nameof(OpenTelemetryLoggerProvider));
             }
 
             base.Dispose(disposing);

src/OpenTelemetry/Metrics/MeterProviderSdk.cs

@@ -491,6 +491,7 @@ namespace OpenTelemetry.Metrics
                 }
 
                 this.disposed = true;
+                OpenTelemetrySdkEventSource.Log.ProviderDisposed(nameof(MeterProvider));
             }
 
             base.Dispose(disposing);

src/OpenTelemetry/Trace/TracerProviderSdk.cs

@@ -375,6 +375,7 @@ namespace OpenTelemetry.Trace
                 }
 
                 this.disposed = true;
+                OpenTelemetrySdkEventSource.Log.ProviderDisposed(nameof(TracerProvider));
             }
 
             base.Dispose(disposing);