Address PR feedback

Author: amcasey

src/Servers/Kestrel/Core/src/Internal/Http2/Http2Connection.cs

@@ -48,9 +48,22 @@ internal sealed partial class Http2Connection : IHttp2StreamLifetimeHandler, IHt
 
     private const string EnhanceYourCalmMaximumCountProperty = "Microsoft.AspNetCore.Server.Kestrel.Http2.EnhanceYourCalmCount";
 
-    private static readonly int _enhanceYourCalmMaximumCount = AppContext.GetData(EnhanceYourCalmMaximumCountProperty) is int eycMaxCount
-        ? eycMaxCount
-        : 10;
+    private static readonly int _enhanceYourCalmMaximumCount = GetEnhanceYourCalmMaximumCount();
+
+    private static int GetEnhanceYourCalmMaximumCount()
+    {
+        var data = AppContext.GetData(EnhanceYourCalmMaximumCountProperty);
+        if (data is int count)
+        {
+            return count;
+        }
+        if (data is string countStr && int.TryParse(countStr, out var parsed))
+        {
+            return parsed;
+        }
+
+        return 20; // Empirically derived
+    }
 
     // Accumulate _enhanceYourCalmCount over the course of EnhanceYourCalmTickWindowCount ticks.
     // This should make bursts less likely to trigger disconnects.

src/Servers/Kestrel/Core/src/Internal/Http2/Http2FrameWriter.cs

@@ -43,6 +43,8 @@ internal sealed class Http2FrameWriter
 
     private readonly int _maximumFlowControlQueueSize;
 
+    private bool IsMaximumFlowControlQueueSizeEnabled => _maximumFlowControlQueueSize > 0;
+
     private readonly object _writeLock = new object();
     private readonly Http2Frame _outgoingFrame;
     private readonly Http2HeadersEnumerator _headersEnumerator = new Http2HeadersEnumerator();
@@ -106,7 +108,7 @@ public Http2FrameWriter(
             ? 4 * maxStreamsPerConnection
             : (int)ConfiguredMaximumFlowControlQueueSize;
 
-        if (_maximumFlowControlQueueSize < maxStreamsPerConnection)
+        if (IsMaximumFlowControlQueueSizeEnabled && _maximumFlowControlQueueSize < maxStreamsPerConnection)
         {
             _log.Http2FlowControlQueueMaximumTooLow(_connectionContext.ConnectionId, maxStreamsPerConnection, _maximumFlowControlQueueSize);
             _maximumFlowControlQueueSize = maxStreamsPerConnection;
@@ -977,7 +979,7 @@ private void EnqueueWaitingForMoreConnectionWindow(Http2OutputProducer producer)
         _waitingForMoreConnectionWindow.Enqueue(producer);
         // This is re-entrant because abort will cause a final enqueue.
         // Easier to check for that condition than to make each enqueuer reason about what to call.
-        if (!_aborted && _maximumFlowControlQueueSize > 0 && _waitingForMoreConnectionWindow.Count > _maximumFlowControlQueueSize)
+        if (!_aborted && IsMaximumFlowControlQueueSizeEnabled && _waitingForMoreConnectionWindow.Count > _maximumFlowControlQueueSize)
         {
             _log.Http2FlowControlQueueOperationsExceeded(_connectionId, _maximumFlowControlQueueSize);
             _http2Connection.Abort(new ConnectionAbortedException("HTTP/2 connection exceeded the outgoing flow control maximum queue size."));

src/Servers/Kestrel/Core/src/Internal/Infrastructure/KestrelTrace.Http2.cs

@@ -146,13 +146,13 @@ private static partial class Http2Log
 
         // Highest shared ID is 63. New consecutive IDs start at 64
 
-        [LoggerMessage(64, LogLevel.Error, @"Connection id ""{ConnectionId}"" aborted since at least ""{Count}"" ENHANCE_YOUR_CALM responses were required per second.", EventName = "Http2TooManyEnhanceYourCalms")]
+        [LoggerMessage(64, LogLevel.Debug, @"Connection id ""{ConnectionId}"" aborted since at least ""{Count}"" ENHANCE_YOUR_CALM responses were required per second.", EventName = "Http2TooManyEnhanceYourCalms")]
         public static partial void Http2TooManyEnhanceYourCalms(ILogger logger, string connectionId, int count);
 
-        [LoggerMessage(65, LogLevel.Error, @"Connection id ""{ConnectionId}"" exceeded the output flow control maximum queue size of ""{Count}"".", EventName = "Http2FlowControlQueueOperationsExceeded")]
+        [LoggerMessage(65, LogLevel.Debug, @"Connection id ""{ConnectionId}"" exceeded the output flow control maximum queue size of ""{Count}"".", EventName = "Http2FlowControlQueueOperationsExceeded")]
         public static partial void Http2FlowControlQueueOperationsExceeded(ILogger logger, string connectionId, int count);
 
-        [LoggerMessage(66, LogLevel.Trace, @"Connection id ""{ConnectionId}"" configured maximum flow control queue size ""{Actual}"" is less than the maximum streams per connection ""{Expected}"" - increasing to match.", EventName = "Http2FlowControlQueueMaximumTooLow")]
+        [LoggerMessage(66, LogLevel.Debug, @"Connection id ""{ConnectionId}"" configured maximum flow control queue size ""{Actual}"" is less than the maximum streams per connection ""{Expected}"" - increasing to match.", EventName = "Http2FlowControlQueueMaximumTooLow")]
         public static partial void Http2FlowControlQueueMaximumTooLow(ILogger logger, string connectionId, int expected, int actual);
     }
 }