Change to an activity based timeout

docs/docfx/articles/config-files.md

@@ -196,9 +196,10 @@ For additional fields see [ClusterConfig](xref:Yarp.ReverseProxy.Configuration.C
           "RequestHeaderEncoding" : "Latin1" // How to interpret non ASCII characters in header values
         },
         "HttpRequest" : { // Options for sending request to destination
-          "Timeout" : "00:02:00",
+          "ActivityTimeout" : "00:02:00",
           "Version" : "2",
-          "VersionPolicy" : "RequestVersionOrLower"
+          "VersionPolicy" : "RequestVersionOrLower",
+          "AllowResponseBuffering" : "false"
         },
         "MetaData" : { // Custom Key value pairs
           "TransportFailureRateHealthPolicy.RateLimit": "0.5", // Used by Passive health policy

docs/docfx/articles/direct-forwarding.md

@@ -56,7 +56,7 @@ public void Configure(IApplicationBuilder app, IHttpForwarder forwarder)
         UseCookies = false
     });
     var transformer = new CustomTransformer(); // or HttpTransformer.Default;
-    var requestOptions = new RequestProxyOptions { Timeout = TimeSpan.FromSeconds(100) };
+    var requestConfig = new ForwarderRequestConfig { ActivityTimeout = TimeSpan.FromSeconds(100) };
 
     app.UseRouting();
     app.UseAuthorization();
@@ -65,7 +65,7 @@ public void Configure(IApplicationBuilder app, IHttpForwarder forwarder)
         endpoints.Map("/{**catch-all}", async httpContext =>
         {
             var error = await forwarder.SendAsync(httpContext, "https://localhost:10000/",
-                httpClient, requestOptions, transformer);
+                httpClient, requestConfig, transformer);
             // Check if the operation was successful
             if (error != ForwarderError.None)
             {

docs/docfx/articles/http-client-config.md

@@ -84,15 +84,15 @@ At the moment, there is no solution for changing encoding for response headers i
 HTTP request configuration is based on [ForwarderRequestConfig](xref:Yarp.ReverseProxy.Forwarder.ForwarderRequestConfig) and represented by the following configuration schema.
 ```JSON
 "HttpRequest": {
-    "Timeout": "<timespan>",
+    "ActivityTimeout": "<timespan>",
     "Version": "<string>",
     "VersionPolicy": ["RequestVersionOrLower", "RequestVersionOrHigher", "RequestVersionExact"],
     "AllowResponseBuffering": "<bool>"
 }
 ```
 
 Configuration settings:
-- Timeout - the timeout for the outgoing request sent by [HttpMessageInvoker.SendAsync](https://docs.microsoft.com/dotnet/api/system.net.http.httpmessageinvoker.sendasync). If not specified, 100 seconds is used.
+- ActivityTimeout - how long a request is allowed to remain idle between any operation completing, after which it will be canceled. The default is 100 seconds. The timeout will reset when response headers are received or after successfully reading or writing any request, response, or streaming data like gRPC or WebSockets. TCP keep-alives and HTTP/2 protocol pings will not reset the timeout, but WebSocket pings will.
 - Version - outgoing request [version](https://docs.microsoft.com/dotnet/api/system.net.http.httprequestmessage.version). The supported values at the moment are `1.0`, `1.1` and `2`. Default value is 2.
 - VersionPolicy - defines how the final version is selected for the outgoing requests. **This feature is available from .NET 5.0**, see [HttpRequestMessage.VersionPolicy](https://docs.microsoft.com/dotnet/api/system.net.http.httprequestmessage.versionpolicy). The default value is `RequestVersionOrLower`.
 - AllowResponseBuffering - allows to use write buffering when sending a response back to the client, if the server hosting YARP (e.g. IIS) supports it. **NOTE**: enabling it can break SSE (server side event) scenarios.
@@ -115,7 +115,7 @@ The below example shows 2 samples of HTTP client and request configurations for
                 "DangerousAcceptAnyServerCertificate": "true"
             },
             "HttpRequest": {
-                "Timeout": "00:00:30"
+                "ActivityTimeout": "00:00:30"
             },
             "Destinations": {
                 "cluster1/destination1": {

samples/ReverseProxy.Direct.Sample/Startup.cs

@@ -43,7 +43,7 @@ public void Configure(IApplicationBuilder app, IHttpForwarder forwarder)
 
             // Setup our own request transform class
             var transformer = new CustomTransformer(); // or HttpTransformer.Default;
-            var requestOptions = new ForwarderRequestConfig { Timeout = TimeSpan.FromSeconds(100) };
+            var requestOptions = new ForwarderRequestConfig { ActivityTimeout = TimeSpan.FromSeconds(100) };
 
             app.UseRouting();
             app.UseEndpoints(endpoints =>

src/ReverseProxy/Configuration/ConfigProvider/ConfigurationConfigProvider.cs

@@ -362,7 +362,7 @@ private static RouteQueryParameter CreateRouteQueryParameter(IConfigurationSecti
 
             return new ForwarderRequestConfig
             {
-                Timeout = section.ReadTimeSpan(nameof(ForwarderRequestConfig.Timeout)),
+                ActivityTimeout = section.ReadTimeSpan(nameof(ForwarderRequestConfig.ActivityTimeout)),
                 Version = section.ReadVersion(nameof(ForwarderRequestConfig.Version)),
 #if NET
                 VersionPolicy = section.ReadEnum<HttpVersionPolicy>(nameof(ForwarderRequestConfig.VersionPolicy)),

src/ReverseProxy/Configuration/HeaderMatchMode.cs

@@ -31,7 +31,7 @@ public enum HeaderMatchMode
         /// </summary>
         Contains,
 
-        // <summary>
+        /// <summary>
         /// The header name must exist and the value must be non-empty and not match, subject to case sensitivity settings.
         /// If there are multiple values then it needs to not contain ANY of the values 
         /// Only single headers are supported. If there are multiple headers with the same name then the match fails.

src/ReverseProxy/Forwarder/ForwarderRequestConfig.cs

@@ -17,10 +17,12 @@ public sealed record ForwarderRequestConfig
         public static ForwarderRequestConfig Empty { get; } = new();
 
         /// <summary>
-        /// The time allowed to send the request and receive the response headers. This may include
-        /// the time needed to send the request body. The default is 100 seconds.
+        /// How long a request is allowed to remain idle between any operation completing, after which it will be canceled.
+        /// The default is 100 seconds. The timeout will reset when response headers are received or after successfully reading or
+        /// writing any request, response, or streaming data like gRPC or WebSockets. TCP keep-alives and HTTP/2 protocol pings will
+        /// not reset the timeout, but WebSocket pings will.
         /// </summary>
-        public TimeSpan? Timeout { get; init; }
+        public TimeSpan? ActivityTimeout { get; init; }
 
         /// <summary>
         /// Preferred version of the outgoing request.
@@ -50,7 +52,7 @@ public bool Equals(ForwarderRequestConfig? other)
                 return false;
             }
 
-            return Timeout == other.Timeout
+            return ActivityTimeout == other.ActivityTimeout
 #if NET
                 && VersionPolicy == other.VersionPolicy
 #endif
@@ -60,7 +62,7 @@ public bool Equals(ForwarderRequestConfig? other)
 
         public override int GetHashCode()
         {
-            return HashCode.Combine(Timeout,
+            return HashCode.Combine(ActivityTimeout,
 #if NET
                 VersionPolicy,
 #endif

src/ReverseProxy/Forwarder/HttpForwarder.cs

@@ -106,8 +106,9 @@ public async ValueTask<ForwarderError> SendAsync(
 
             ForwarderTelemetry.Log.ForwarderStart(destinationPrefix);
 
-            var requestCancellationSource = CancellationTokenSource.CreateLinkedTokenSource(context.RequestAborted);
-            requestCancellationSource.CancelAfter(requestConfig?.Timeout ?? DefaultTimeout);
+            var activityCancellationSource = CancellationTokenSource.CreateLinkedTokenSource(context.RequestAborted);
+            var activityTimeout = requestConfig?.ActivityTimeout ?? DefaultTimeout;
+            activityCancellationSource.CancelAfter(activityTimeout);
             try
             {
                 var isClientHttp2 = ProtocolHelper.IsHttp2(context.Request.Protocol);
@@ -118,22 +119,22 @@ public async ValueTask<ForwarderError> SendAsync(
 
                 // :: Step 1-3: Create outgoing HttpRequestMessage
                 var (destinationRequest, requestContent) = await CreateRequestMessageAsync(
-                    context, destinationPrefix, transformer, requestConfig, isStreamingRequest, requestCancellationSource.Token);
+                    context, destinationPrefix, transformer, requestConfig, isStreamingRequest, activityCancellationSource, activityTimeout);
 
                 // :: Step 4: Send the outgoing request using HttpClient
                 HttpResponseMessage destinationResponse;
                 try
                 {
                     ForwarderTelemetry.Log.ForwarderStage(ForwarderStage.SendAsyncStart);
-                    destinationResponse = await httpClient.SendAsync(destinationRequest, requestCancellationSource.Token);
+                    destinationResponse = await httpClient.SendAsync(destinationRequest, activityCancellationSource.Token);
                     ForwarderTelemetry.Log.ForwarderStage(ForwarderStage.SendAsyncStop);
 
-                    // Remove the timeout, only listen to the linked token / manual Cancel from now on
-                    requestCancellationSource.CancelAfter(Timeout.Infinite);
+                    // Reset the timeout since we received the response headers.
+                    activityCancellationSource.CancelAfter(activityTimeout);
                 }
                 catch (Exception requestException)
                 {
-                    return await HandleRequestFailureAsync(context, requestContent, requestException, transformer, requestCancellationSource);
+                    return await HandleRequestFailureAsync(context, requestContent, requestException, transformer, activityCancellationSource);
                 }
 
                 // Detect connection downgrade, which may be problematic for e.g. gRPC.
@@ -156,7 +157,7 @@ public async ValueTask<ForwarderError> SendAsync(
 
                         if (requestContent is not null && requestContent.InProgress)
                         {
-                            requestCancellationSource.Cancel();
+                            activityCancellationSource.Cancel();
                             await requestContent.ConsumptionTask;
                         }
 
@@ -169,7 +170,7 @@ public async ValueTask<ForwarderError> SendAsync(
 
                     if (requestContent is not null && requestContent.InProgress)
                     {
-                        requestCancellationSource.Cancel();
+                        activityCancellationSource.Cancel();
                         await requestContent.ConsumptionTask;
                     }
 
@@ -184,7 +185,7 @@ public async ValueTask<ForwarderError> SendAsync(
                 if (destinationResponse.StatusCode == HttpStatusCode.SwitchingProtocols)
                 {
                     Debug.Assert(requestContent?.Started != true);
-                    return await HandleUpgradedResponse(context, destinationResponse, context.RequestAborted);
+                    return await HandleUpgradedResponse(context, destinationResponse, activityCancellationSource, activityTimeout);
                 }
 
                 // NOTE: it may *seem* wise to call `context.Response.StartAsync()` at this point
@@ -198,11 +199,11 @@ public async ValueTask<ForwarderError> SendAsync(
                 // and clients misbehave if the initial headers response does not indicate stream end.
 
                 // :: Step 7-B: Copy response body Client ◄-- Proxy ◄-- Destination
-                var (responseBodyCopyResult, responseBodyException) = await CopyResponseBodyAsync(destinationResponse.Content, context.Response.Body, context.RequestAborted);
+                var (responseBodyCopyResult, responseBodyException) = await CopyResponseBodyAsync(destinationResponse.Content, context.Response.Body, activityCancellationSource, activityTimeout);
 
                 if (responseBodyCopyResult != StreamCopyResult.Success)
                 {
-                    return await HandleResponseBodyErrorAsync(context, requestContent, responseBodyCopyResult, responseBodyException!, requestCancellationSource);
+                    return await HandleResponseBodyErrorAsync(context, requestContent, responseBodyCopyResult, responseBodyException!, activityCancellationSource);
                 }
 
                 // :: Step 8: Copy response trailer headers and finish response Client ◄-- Proxy ◄-- Destination
@@ -247,15 +248,15 @@ public async ValueTask<ForwarderError> SendAsync(
             }
             finally
             {
-                requestCancellationSource.Dispose();
+                activityCancellationSource.Dispose();
                 ForwarderTelemetry.Log.ForwarderStop(context.Response.StatusCode);
             }
 
             return ForwarderError.None;
         }
 
         private async ValueTask<(HttpRequestMessage, StreamCopyHttpContent?)> CreateRequestMessageAsync(HttpContext context, string destinationPrefix,
-            HttpTransformer transformer, ForwarderRequestConfig? requestConfig, bool isStreamingRequest, CancellationToken contentCancellation)
+            HttpTransformer transformer, ForwarderRequestConfig? requestConfig, bool isStreamingRequest, CancellationTokenSource activityToken, TimeSpan activityTimeout)
         {
             // "http://a".Length = 8
             if (destinationPrefix == null || destinationPrefix.Length < 8)
@@ -287,7 +288,7 @@ public async ValueTask<ForwarderError> SendAsync(
 
             // :: Step 2: Setup copy of request body (background) Client --► Proxy --► Destination
             // Note that we must do this before step (3) because step (3) may also add headers to the HttpContent that we set up here.
-            var requestContent = SetupRequestBodyCopy(context.Request, isStreamingRequest, contentCancellation);
+            var requestContent = SetupRequestBodyCopy(context.Request, isStreamingRequest, activityToken, activityTimeout);
             destinationRequest.Content = requestContent;
 
             // :: Step 3: Copy request headers Client --► Proxy --► Destination
@@ -333,7 +334,7 @@ private static void RestoreUpgradeHeaders(HttpContext context, HttpRequestMessag
             }
         }
 
-        private StreamCopyHttpContent? SetupRequestBodyCopy(HttpRequest request, bool isStreamingRequest, CancellationToken contentCancellation)
+        private StreamCopyHttpContent? SetupRequestBodyCopy(HttpRequest request, bool isStreamingRequest, CancellationTokenSource activityToken, TimeSpan activityTimeout)
         {
             // If we generate an HttpContent without a Content-Length then for HTTP/1.1 HttpClient will add a Transfer-Encoding: chunked header
             // even if it's a GET request. Some servers reject requests containing a Transfer-Encoding header if they're not expecting a body.
@@ -409,7 +410,8 @@ private static void RestoreUpgradeHeaders(HttpContext context, HttpRequestMessag
                     source: request.Body,
                     autoFlushHttpClientOutgoingStream: isStreamingRequest,
                     clock: _clock,
-                    cancellation: contentCancellation);
+                    activityToken,
+                    activityTimeout);
             }
 
             return null;
@@ -544,7 +546,7 @@ private static void RestoreUpgradeHeaders(HttpContext context, HttpResponseMessa
         }
 
         private async ValueTask<ForwarderError> HandleUpgradedResponse(HttpContext context, HttpResponseMessage destinationResponse,
-            CancellationToken longCancellation)
+            CancellationTokenSource activityCancellationSource, TimeSpan activityTimeout)
         {
             ForwarderTelemetry.Log.ForwarderStage(ForwarderStage.ResponseUpgrade);
 
@@ -576,10 +578,8 @@ private async ValueTask<ForwarderError> HandleUpgradedResponse(HttpContext conte
             // :: Step 7-A-2: Copy duplex streams
             using var destinationStream = await destinationResponse.Content.ReadAsStreamAsync();
 
-            using var abortTokenSource = CancellationTokenSource.CreateLinkedTokenSource(longCancellation);
-
-            var requestTask = StreamCopier.CopyAsync(isRequest: true, clientStream, destinationStream, _clock, abortTokenSource.Token).AsTask();
-            var responseTask = StreamCopier.CopyAsync(isRequest: false, destinationStream, clientStream, _clock, abortTokenSource.Token).AsTask();
+            var requestTask = StreamCopier.CopyAsync(isRequest: true, clientStream, destinationStream, _clock, activityCancellationSource, activityTimeout).AsTask();
+            var responseTask = StreamCopier.CopyAsync(isRequest: false, destinationStream, clientStream, _clock, activityCancellationSource, activityTimeout).AsTask();
 
             // Make sure we report the first failure.
             var firstTask = await Task.WhenAny(requestTask, responseTask);
@@ -593,7 +593,7 @@ private async ValueTask<ForwarderError> HandleUpgradedResponse(HttpContext conte
             {
                 error = ReportResult(context, requestFinishedFirst, firstResult, firstException);
                 // Cancel the other direction
-                abortTokenSource.Cancel();
+                activityCancellationSource.Cancel();
                 // Wait for this to finish before exiting so the resources get cleaned up properly.
                 await secondTask;
             }
@@ -627,7 +627,7 @@ ForwarderError ReportResult(HttpContext context, bool reqeuest, StreamCopyResult
         }
 
         private async ValueTask<(StreamCopyResult, Exception?)> CopyResponseBodyAsync(HttpContent destinationResponseContent, Stream clientResponseStream,
-            CancellationToken cancellation)
+            CancellationTokenSource activityCancellationSource, TimeSpan activityTimeout)
         {
             // SocketHttpHandler and similar transports always provide an HttpContent object, even if it's empty.
             // In 3.1 this is only likely to return null in tests.
@@ -636,7 +636,7 @@ ForwarderError ReportResult(HttpContext context, bool reqeuest, StreamCopyResult
             if (destinationResponseContent != null)
             {
                 using var destinationResponseStream = await destinationResponseContent.ReadAsStreamAsync();
-                return await StreamCopier.CopyAsync(isRequest: false, destinationResponseStream, clientResponseStream, _clock, cancellation);
+                return await StreamCopier.CopyAsync(isRequest: false, destinationResponseStream, clientResponseStream, _clock, activityCancellationSource, activityTimeout);
             }
 
             return (StreamCopyResult.Success, null);