From 80ce884f64e754823cc240921393c66bca300c14 Mon Sep 17 00:00:00 2001
From: Gaurav Goel <gaurav.goel111@gmail.com>
Date: Sun, 9 Oct 2022 17:51:51 +0530
Subject: [PATCH] Logging state during building of TracerProvider

---
 .../Internal/OpenTelemetrySdkEventSource.cs   |  7 ++++++
 src/OpenTelemetry/Trace/TracerProviderSdk.cs  | 23 +++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs b/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs
index f9f6b6f2ed8..8cbb811afa6 100644
--- a/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs
+++ b/src/OpenTelemetry/Internal/OpenTelemetrySdkEventSource.cs
@@ -408,6 +408,13 @@ public void OpenTelemetryLoggerProviderForceFlushInvoked(int timeoutMilliseconds
             this.WriteEvent(45, timeoutMilliseconds);
         }
 
+        [Event(46, Message = "TracerProviderSdk event: '{0}'", Level = EventLevel.Verbose)]
+        public void TracerProviderSdkEvent(string message)
+        {
+            this.WriteEvent(46, message);
+        }
+
+
 #if DEBUG
         public class OpenTelemetryEventListener : EventListener
         {
diff --git a/src/OpenTelemetry/Trace/TracerProviderSdk.cs b/src/OpenTelemetry/Trace/TracerProviderSdk.cs
index 13d3d969cb0..b8b0f14919f 100644
--- a/src/OpenTelemetry/Trace/TracerProviderSdk.cs
+++ b/src/OpenTelemetry/Trace/TracerProviderSdk.cs
@@ -21,6 +21,7 @@
 using System.Diagnostics;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using System.Text;
 using OpenTelemetry.Internal;
 using OpenTelemetry.Resources;
 
@@ -49,12 +50,17 @@ internal TracerProviderSdk(
                 Debug.Assert(this.OwnedServiceProvider != null, "serviceProvider was not IDisposable");
             }
 
+            OpenTelemetrySdkEventSource.Log.TracerProviderSdkEvent("Building TracerProvider.");
+
             var state = new TracerProviderBuilderState(serviceProvider);
 
             TracerProviderBuilderServiceCollectionHelper.InvokeRegisteredConfigureStateCallbacks(
                 serviceProvider,
                 state);
 
+            StringBuilder processorsAdded = new StringBuilder();
+            StringBuilder instrumentationFactoriesAdded = new StringBuilder();
+
             if (state.SetErrorStatusOnException)
             {
                 state.EnableErrorStatusOnException();
@@ -79,11 +85,27 @@ internal TracerProviderSdk(
             foreach (var processor in state.Processors)
             {
                 this.AddProcessor(processor);
+                processorsAdded.Append(processor.GetType());
+                processorsAdded.Append(';');
             }
 
             foreach (var instrumentation in state.Instrumentation)
             {
                 this.instrumentations.Add(instrumentation.Instance);
+                instrumentationFactoriesAdded.Append(instrumentation.Name);
+                instrumentationFactoriesAdded.Append(';');
+            }
+
+            if (processorsAdded.Length != 0)
+            {
+                processorsAdded.Remove(processorsAdded.Length - 1, 1);
+                OpenTelemetrySdkEventSource.Log.TracerProviderSdkEvent($"Processors added = \"{processorsAdded}\".");
+            }
+
+            if (instrumentationFactoriesAdded.Length != 0)
+            {
+                instrumentationFactoriesAdded.Remove(instrumentationFactoriesAdded.Length - 1, 1);
+                OpenTelemetrySdkEventSource.Log.TracerProviderSdkEvent($"Instrumentations added = \"{instrumentationFactoriesAdded}\".");
             }
 
             var listener = new ActivityListener();
@@ -264,6 +286,7 @@ internal TracerProviderSdk(
 
             ActivitySource.AddActivityListener(listener);
             this.listener = listener;
+            OpenTelemetrySdkEventSource.Log.TracerProviderSdkEvent("TracerProvider built successfully.");
         }
 
         internal Resource Resource { get; }