Set connection expiration timeouts (#19524)

sdk/core/Azure.Core/Azure.Core.sln

@@ -27,6 +27,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.Azure.Core.Spatia
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Azure.Core.Perf", "perf\Azure.Core.Perf.csproj", "{B6D7909F-4DE6-4895-BF39-EF892BA64BA3}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Azure.Test.Perf", "..\..\..\common\Perf\Azure.Test.Perf\Azure.Test.Perf.csproj", "{33A10110-D88A-459B-82C1-FECEF86A822A}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -81,6 +83,10 @@ Global
 		{B6D7909F-4DE6-4895-BF39-EF892BA64BA3}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B6D7909F-4DE6-4895-BF39-EF892BA64BA3}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B6D7909F-4DE6-4895-BF39-EF892BA64BA3}.Release|Any CPU.Build.0 = Release|Any CPU
+		{33A10110-D88A-459B-82C1-FECEF86A822A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{33A10110-D88A-459B-82C1-FECEF86A822A}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{33A10110-D88A-459B-82C1-FECEF86A822A}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{33A10110-D88A-459B-82C1-FECEF86A822A}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

sdk/core/Azure.Core/CHANGELOG.md

@@ -6,6 +6,7 @@
 
 - Check the `JsonIgnoreAttribute.Condition` property added in .NET 5 when discovering members with `JsonObjectSerializer`.
 - `ETag` now returns `string.Empty` if it is constructed with a null value.
+- Keep-Alive connections are recycled every 300 seconds to observe DNS changes. 
 
 ## 1.10.0 (2021-03-09)
 

sdk/core/Azure.Core/src/Azure.Core.csproj

@@ -5,10 +5,12 @@
     <Version>1.11.0-beta.1</Version>
     <!--The ApiCompatVersion is managed automatically and should not generally be modified manually.-->
     <ApiCompatVersion>1.10.0</ApiCompatVersion>
+    <!-- TODO: remove when we have a released package with the netcoreapp2.1 target -->
+    <ApiCompatVersion Condition="$(TargetFramework) == 'netcoreapp2.1'"></ApiCompatVersion>
     <PackageTags>Microsoft Azure Client Pipeline</PackageTags>
     <Nullable>enable</Nullable>
     <DefineConstants>$(DefineConstants);AZURE_NULLABLE</DefineConstants>
-    <TargetFrameworks>$(RequiredTargetFrameworks);net461;net5.0</TargetFrameworks>
+    <TargetFrameworks>$(RequiredTargetFrameworks);net461;netcoreapp2.1;net5.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <EnableClientSdkAnalyzers>true</EnableClientSdkAnalyzers>
   </PropertyGroup>

sdk/core/Azure.Core/src/Internal/AzureBaseBuffersExtensions.cs

@@ -16,7 +16,7 @@ internal static class AzureBaseBuffersExtensions
         public static async Task WriteAsync(this Stream stream, ReadOnlyMemory<byte> buffer, CancellationToken cancellation = default)
         {
             Argument.AssertNotNull(stream, nameof(stream));
-#if NET5_0
+#if NETCOREAPP
             await stream.WriteAsync(buffer, cancellation).ConfigureAwait(false);
 #else
 
@@ -58,7 +58,7 @@ public static async Task WriteAsync(this Stream stream, ReadOnlySequence<byte> b
             {
                 foreach (ReadOnlyMemory<byte> segment in buffer)
                 {
-#if NET5_0
+#if NETCOREAPP
                     await stream.WriteAsync(segment, cancellation).ConfigureAwait(false);
 #else
                     if (MemoryMarshal.TryGetArray(segment, out ArraySegment<byte> arraySegment))

sdk/core/Azure.Core/src/Pipeline/HttpClientTransport.cs

@@ -127,17 +127,20 @@ private async ValueTask ProcessAsync(HttpMessage message, bool async)
 
         private static HttpClient CreateDefaultClient()
         {
-            var httpClientHandler = new HttpClientHandler();
+#if NETFRAMEWORK || NETSTANDARD
+            HttpClientHandler httpMessageHandler = new HttpClientHandler();
+#else
+
+            SocketsHttpHandler httpMessageHandler = new SocketsHttpHandler();
+#endif
             if (HttpEnvironmentProxy.TryCreate(out IWebProxy webProxy))
             {
-                httpClientHandler.Proxy = webProxy;
+                httpMessageHandler.Proxy = webProxy;
             }
 
-#if NETFRAMEWORK
-            ServicePointHelpers.SetLimits(httpClientHandler);
-#endif
+            ServicePointHelpers.SetLimits(httpMessageHandler);
 
-            return new HttpClient(httpClientHandler)
+            return new HttpClient(httpMessageHandler)
             {
                 // Timeouts are handled by the pipeline
                 Timeout = Timeout.InfiniteTimeSpan

sdk/core/Azure.Core/src/Pipeline/ServicePointHelpers.cs

@@ -1,15 +1,33 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+using System;
 using System.Net;
 using System.Net.Http;
+using System.Threading;
 
 namespace Azure.Core.Pipeline
 {
+    // This type manages changing HttpClient/HttpWebRequest defaults to more appropriate values
+    // There are two limits we target:
+    // - Per Server Connection Limit
+    // - Keep Alive Connection Timeout
+    // On .NET Core 2.1 & NET 5.0 the HttpClientTransport would default to using the SocketClientHandler
+    //   we adjust both limits on the client handler
+    // On .NET Standard & NET 4.6+ the HttpClientTransport would default to using the HttpClientHandler
+    //   and there is no easy way to set Keep Alive Connection Timeout but it's mitigated by WebHttpRequestTransport
+    //   being the default on NET 4.6.1
+    // The default transport on NET 4.6.1 is WebHttpRequestTransport the default and we are updating both
+    //  limits on the service point
+
     internal static class ServicePointHelpers
     {
         private const int RuntimeDefaultConnectionLimit = 2;
         private const int IncreasedConnectionLimit = 50;
+        private const int IncreasedConnectionLeaseTimeout = 300 * 1000;
+
+#if NETFRAMEWORK || NETSTANDARD
+        private const int DefaultConnectionLeaseTimeout = Timeout.Infinite;
 
         public static void SetLimits(ServicePoint requestServicePoint)
         {
@@ -18,15 +36,36 @@ public static void SetLimits(ServicePoint requestServicePoint)
             {
                 requestServicePoint.ConnectionLimit = IncreasedConnectionLimit;
             }
+
+            if (requestServicePoint.ConnectionLeaseTimeout == DefaultConnectionLeaseTimeout)
+            {
+                requestServicePoint.ConnectionLeaseTimeout = IncreasedConnectionLeaseTimeout;
+            }
         }
 
-        public static void SetLimits(HttpClientHandler requestServicePoint)
+        public static void SetLimits(HttpClientHandler httpClientHandler)
         {
             // Only change when the default runtime limit is used
-            if (requestServicePoint.MaxConnectionsPerServer == RuntimeDefaultConnectionLimit)
+            if (httpClientHandler.MaxConnectionsPerServer == RuntimeDefaultConnectionLimit)
+            {
+                httpClientHandler.MaxConnectionsPerServer = IncreasedConnectionLimit;
+            }
+        }
+#else // NETCOREAPP +
+        private static TimeSpan DefaultConnectionLeaseTimeoutTimeSpan = Timeout.InfiniteTimeSpan;
+        private static TimeSpan IncreasedConnectionLeaseTimeoutTimeSpan = TimeSpan.FromMilliseconds(IncreasedConnectionLeaseTimeout);
+
+        public static void SetLimits(SocketsHttpHandler socketsHttpHandler)
+        {
+            if (socketsHttpHandler.MaxConnectionsPerServer == RuntimeDefaultConnectionLimit)
+            {
+                socketsHttpHandler.MaxConnectionsPerServer = IncreasedConnectionLimit;
+            }
+            if (socketsHttpHandler.PooledConnectionLifetime == DefaultConnectionLeaseTimeoutTimeSpan)
             {
-                requestServicePoint.MaxConnectionsPerServer = IncreasedConnectionLimit;
+                socketsHttpHandler.PooledConnectionLifetime = IncreasedConnectionLeaseTimeoutTimeSpan;
             }
         }
+#endif
     }
 }

sdk/core/Azure.Core/src/Shared/NullableAttributes.cs

@@ -6,7 +6,7 @@
 #pragma warning disable SA1402 // File may only contain a single type
 #pragma warning disable SA1649 // File name should match first type name
 
-#if !NETCOREAPP
+#if !NET5_0
 namespace System.Diagnostics.CodeAnalysis
 {
     /// <summary>Specifies that null is allowed as an input even if the corresponding type disallows it.</summary>