SNOW-834807: Allow users to configure ServicePointManager.ConnectionLimit property (#1224)

sfc-gh-ext-simba-lf · sfc-gh-mgemra · web-flow · commit 07abb0d67ae7 · 2025-10-27T16:03:21.000+01:00
Co-authored-by: Marcin Gemra &lt;marcin.gemra@snowflake.com&gt;
diff --git a/Snowflake.Data.Tests/IntegrationTests/CertificateRevocationIT.cs b/Snowflake.Data.Tests/IntegrationTests/CertificateRevocationIT.cs
@@ -26,6 +26,7 @@ public void TestCertificate()
                 false,
                 false,
                 3,
+                20,
                 true,
                 CertRevocationCheckMode.Enabled.ToString(),
                 true,
diff --git a/Snowflake.Data.Tests/UnitTests/HttpUtilTest.cs b/Snowflake.Data.Tests/UnitTests/HttpUtilTest.cs
@@ -35,7 +35,7 @@ public async Task TestNonRetryableHttpExceptionThrowsError()
             .ThrowsAsync(new HttpRequestException("", new AuthenticationException()));
 
             var httpClient = HttpUtil.Instance.GetHttpClient(
-                new HttpClientConfig("fakeHost", "fakePort", "user", "password", "fakeProxyList", false, false, 7, certRevocationCheckMode: "ENABLED"),
+                new HttpClientConfig("fakeHost", "fakePort", "user", "password", "fakeProxyList", false, false, 7, 20, certRevocationCheckMode: "ENABLED"),
                 handler.Object);
 
             try
@@ -150,7 +150,8 @@ public void TestCreateHttpClientHandlerWithProxy()
                 "localhost",
                 false,
                 false,
-                7
+                7,
+                20
             );
 
             // act
@@ -173,6 +174,7 @@ public void TestCreateHttpClientHandlerWithoutProxy()
                 null,
                 false,
                 false,
+                20,
                 0
             );
 
diff --git a/Snowflake.Data.Tests/UnitTests/Revocation/CertificateRevocationVerifierTest.cs b/Snowflake.Data.Tests/UnitTests/Revocation/CertificateRevocationVerifierTest.cs
@@ -277,6 +277,7 @@ private HttpClientConfig GetHttpConfig(CertRevocationCheckMode checkMode = CertR
                 false,
                 false,
                 3,
+                20,
                 true,
                 checkMode.ToString(),
                 false,
diff --git a/Snowflake.Data.Tests/UnitTests/Session/SFHttpClientPropertiesTest.cs b/Snowflake.Data.Tests/UnitTests/Session/SFHttpClientPropertiesTest.cs
@@ -53,6 +53,86 @@ public void TestConvertToMapOnly2Properties(
             Assert.AreEqual(clientStoreTemporaryCredential, parameterMap[SFSessionParameter.CLIENT_STORE_TEMPORARY_CREDENTIAL]);
         }
 
+        [Test]
+        [TestCase(1)]
+        [TestCase(10)]
+        [TestCase(100)]
+        public void TestSettingConnectionLimitProperty(int expectedConnectionLimit)
+        {
+            // arrange
+            var connectionString = $"ACCOUNT=account;USER=test;PASSWORD=test;SERVICE_POINT_CONNECTION_LIMIT={expectedConnectionLimit}";
+            var properties = SFSessionProperties.ParseConnectionString(connectionString, new SessionPropertiesContext());
+
+            // act
+            var extractedProperties = SFSessionHttpClientProperties.ExtractAndValidate(properties);
+
+            // assert
+            Assert.AreEqual(expectedConnectionLimit, extractedProperties._servicePointConnectionLimit);
+        }
+
+        [Test]
+        public void TestSettingConnectionLimitPropertyToLessThan1()
+        {
+            // arrange
+            var connectionString = $"ACCOUNT=account;USER=test;PASSWORD=test;SERVICE_POINT_CONNECTION_LIMIT={0}";
+            var properties = SFSessionProperties.ParseConnectionString(connectionString, new SessionPropertiesContext());
+
+            // act
+            var extractedProperties = SFSessionHttpClientProperties.ExtractAndValidate(properties);
+
+            // assert
+            Assert.AreEqual(SFSessionHttpClientProperties.DefaultConnectionLimit, extractedProperties._servicePointConnectionLimit);
+        }
+
+        [Test]
+        public void TestSettingConnectionLimitPropertyToGreaterThanMaxConnectionLimit()
+        {
+            // arrange
+            var connectionString = $"ACCOUNT=account;USER=test;PASSWORD=test;SERVICE_POINT_CONNECTION_LIMIT={SFSessionHttpClientProperties.MaxConnectionLimit + 1}";
+            var properties = SFSessionProperties.ParseConnectionString(connectionString, new SessionPropertiesContext());
+
+            // act
+            var extractedProperties = SFSessionHttpClientProperties.ExtractAndValidate(properties);
+
+            // assert
+            Assert.AreEqual(SFSessionHttpClientProperties.DefaultConnectionLimit, extractedProperties._servicePointConnectionLimit);
+        }
+
+        [Test]
+        public void TestSettingConnectionLimitPropertyToNoValue()
+        {
+            // arrange
+            var connectionString = $"ACCOUNT=account;USER=test;PASSWORD=test;SERVICE_POINT_CONNECTION_LIMIT=";
+            var properties = SFSessionProperties.ParseConnectionString(connectionString, new SessionPropertiesContext());
+
+            // act
+            var extractedProperties = SFSessionHttpClientProperties.ExtractAndValidate(properties);
+
+            // assert
+            Assert.AreEqual(SFSessionHttpClientProperties.DefaultConnectionLimit, extractedProperties._servicePointConnectionLimit);
+        }
+
+        [Test]
+        [TestCase("abc")]
+        [TestCase("1.5")]
+        [TestCase("true")]
+        [TestCase("-2.3")]
+        [TestCase("null")]
+        public void TestThrowsExceptionWhenSettingConnectionLimitPropertyToNonIntegerValue(string nonIntegerValue)
+        {
+            // arrange
+            var parameterName = "SERVICE_POINT_CONNECTION_LIMIT";
+            var expectedErrorMessage = $"Error: Invalid parameter value  for {parameterName}";
+            var connectionString = $"ACCOUNT=account;USER=test;PASSWORD=test;{parameterName}={nonIntegerValue}";
+
+            // act
+            var thrown = Assert.Throws<SnowflakeDbException>(() => SFSessionProperties.ParseConnectionString(connectionString, new SessionPropertiesContext()));
+
+            // assert
+            Assert.AreEqual(SFError.INVALID_CONNECTION_PARAMETER_VALUE.GetAttribute<SFErrorAttr>().errorCode, thrown.ErrorCode);
+            Assert.IsTrue(thrown.Message.Contains(expectedErrorMessage));
+        }
+
         [Test]
         public void TestBuildHttpClientConfig()
         {
diff --git a/Snowflake.Data/Core/HttpUtil.cs b/Snowflake.Data/Core/HttpUtil.cs
@@ -27,6 +27,7 @@ public HttpClientConfig(
             bool disableRetry,
             bool forceRetryOn404,
             int maxHttpRetries,
+            int connectionLimit,
             bool includeRetryReason = true,
             string certRevocationCheckMode = "DISABLED",
             bool enableCRLDiskCaching = true,
@@ -46,6 +47,7 @@ public HttpClientConfig(
             ForceRetryOn404 = forceRetryOn404;
             MaxHttpRetries = maxHttpRetries;
             IncludeRetryReason = includeRetryReason;
+            ConnectionLimit = connectionLimit;
             CertRevocationCheckMode = (CertRevocationCheckMode)Enum.Parse(typeof(CertRevocationCheckMode), certRevocationCheckMode, true);
             EnableCRLDiskCaching = enableCRLDiskCaching;
             EnableCRLInMemoryCaching = enableCRLInMemoryCaching;
@@ -65,6 +67,7 @@ public HttpClientConfig(
                     forceRetryOn404.ToString(),
                     maxHttpRetries.ToString(),
                     includeRetryReason.ToString(),
+                    connectionLimit.ToString(),
                     certRevocationCheckMode,
                     enableCRLDiskCaching.ToString(),
                     enableCRLInMemoryCaching.ToString(),
@@ -84,6 +87,7 @@ public HttpClientConfig(
         public readonly bool ForceRetryOn404;
         public readonly int MaxHttpRetries;
         public readonly bool IncludeRetryReason;
+        public readonly int ConnectionLimit;
         internal readonly CertRevocationCheckMode CertRevocationCheckMode;
         internal readonly bool EnableCRLDiskCaching;
         internal readonly bool EnableCRLInMemoryCaching;
@@ -178,7 +182,7 @@ private HttpClient RegisterNewHttpClientIfNecessary(HttpClientConfig config, Del
 
         internal HttpClient CreateNewHttpClient(HttpClientConfig config, DelegatingHandler customHandler = null) =>
             new HttpClient(
-                new RetryHandler(SetupCustomHttpHandler(config, customHandler), config.DisableRetry, config.ForceRetryOn404, config.MaxHttpRetries, config.IncludeRetryReason))
+                new RetryHandler(SetupCustomHttpHandler(config, customHandler), config.DisableRetry, config.ForceRetryOn404, config.MaxHttpRetries, config.IncludeRetryReason, config.ConnectionLimit))
             {
                 Timeout = Timeout.InfiniteTimeSpan
             };
@@ -451,13 +455,15 @@ private class RetryHandler : DelegatingHandler
             private bool forceRetryOn404;
             private int maxRetryCount;
             private bool includeRetryReason;
+            private int connectionLimit;
 
-            internal RetryHandler(HttpMessageHandler innerHandler, bool disableRetry, bool forceRetryOn404, int maxRetryCount, bool includeRetryReason) : base(innerHandler)
+            internal RetryHandler(HttpMessageHandler innerHandler, bool disableRetry, bool forceRetryOn404, int maxRetryCount, bool includeRetryReason, int connectionLimit) : base(innerHandler)
             {
                 this.disableRetry = disableRetry;
                 this.forceRetryOn404 = forceRetryOn404;
                 this.maxRetryCount = maxRetryCount;
                 this.includeRetryReason = includeRetryReason;
+                this.connectionLimit = connectionLimit;
             }
 
             protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage requestMessage,
@@ -474,7 +480,7 @@ protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage
                 ServicePoint p = ServicePointManager.FindServicePoint(requestMessage.RequestUri);
                 p.Expect100Continue = false; // Saves about 100 ms per request
                 p.UseNagleAlgorithm = false; // Saves about 200 ms per request
-                p.ConnectionLimit = 20;      // Default value is 2, we need more connections for performing multiple parallel queries
+                p.ConnectionLimit = connectionLimit;    // Default value is 2, we need more connections for performing multiple parallel queries
 
                 TimeSpan httpTimeout = (TimeSpan)requestMessage.Properties[BaseRestRequest.HTTP_REQUEST_TIMEOUT_KEY];
                 TimeSpan restTimeout = (TimeSpan)requestMessage.Properties[BaseRestRequest.REST_REQUEST_TIMEOUT_KEY];
diff --git a/Snowflake.Data/Core/Session/SFSessionHttpClientProperties.cs b/Snowflake.Data/Core/Session/SFSessionHttpClientProperties.cs
@@ -21,8 +21,10 @@ internal class SFSessionHttpClientProperties
         public static readonly TimeSpan DefaultExpirationTimeout = TimeSpan.FromHours(1);
         public const bool DefaultPoolingEnabled = true;
         public const int DefaultMaxHttpRetries = 7;
+        public const int DefaultConnectionLimit = 20;
         public static readonly TimeSpan DefaultRetryTimeout = TimeSpan.FromSeconds(300);
         private static readonly SFLogger s_logger = SFLoggerFactory.GetLogger<SFSessionHttpClientProperties>();
+        internal static readonly int MaxConnectionLimit = 1000;
 
         internal bool validateDefaultParameters;
         internal bool clientSessionKeepAlive;
@@ -41,6 +43,7 @@ internal class SFSessionHttpClientProperties
         private TimeSpan _expirationTimeout;
         private bool _poolingEnabled;
         internal bool _clientStoreTemporaryCredential;
+        internal int _servicePointConnectionLimit;
         internal CertRevocationCheckMode _certRevocationCheckMode;
         internal bool _enableCrlDiskCaching;
         internal bool _enableCrlInMemoryCaching;
@@ -99,6 +102,7 @@ private void CheckPropertiesAreValid()
                 ValidateHttpRetries();
                 ValidateMinMaxPoolSize();
                 ValidateWaitingForSessionIdleTimeout();
+                ValidateConnectionLimit();
             }
             catch (SnowflakeDbException)
             {
@@ -188,6 +192,15 @@ private void ValidateWaitingForSessionIdleTimeout()
             }
         }
 
+        private void ValidateConnectionLimit()
+        {
+            if (_servicePointConnectionLimit < 1 || _servicePointConnectionLimit > MaxConnectionLimit)
+            {
+                s_logger.Warn($"Connection limit must be between 1 and {MaxConnectionLimit}. Using the default value of {DefaultConnectionLimit}");
+                _servicePointConnectionLimit = DefaultConnectionLimit;
+            }
+        }
+
         public HttpClientConfig BuildHttpClientConfig()
         {
             return new HttpClientConfig(
@@ -199,6 +212,7 @@ public HttpClientConfig BuildHttpClientConfig()
                 disableRetry,
                 forceRetryOn404,
                 maxHttpRetries,
+                _servicePointConnectionLimit,
                 includeRetryReason,
                 _certRevocationCheckMode.ToString(),
                 _enableCrlDiskCaching,
@@ -267,6 +281,7 @@ public SFSessionHttpClientProperties ExtractProperties(SFSessionProperties prope
                     _poolingEnabled = extractor.ExtractBooleanWithDefaultValue(SFSessionProperty.POOLINGENABLED),
                     _disableSamlUrlCheck = extractor.ExtractBooleanWithDefaultValue(SFSessionProperty.DISABLE_SAML_URL_CHECK),
                     _clientStoreTemporaryCredential = Boolean.Parse(propertiesDictionary[SFSessionProperty.CLIENT_STORE_TEMPORARY_CREDENTIAL]),
+                    _servicePointConnectionLimit = int.Parse(propertiesDictionary[SFSessionProperty.SERVICE_POINT_CONNECTION_LIMIT]),
                     _certRevocationCheckMode = (CertRevocationCheckMode)Enum.Parse(typeof(CertRevocationCheckMode), propertiesDictionary[SFSessionProperty.CERTREVOCATIONCHECKMODE], true),
                     _enableCrlDiskCaching = Boolean.Parse(propertiesDictionary[SFSessionProperty.ENABLECRLDISKCACHING]),
                     _enableCrlInMemoryCaching = Boolean.Parse(propertiesDictionary[SFSessionProperty.ENABLECRLINMEMORYCACHING]),
diff --git a/Snowflake.Data/Core/Session/SFSessionProperty.cs b/Snowflake.Data/Core/Session/SFSessionProperty.cs
@@ -132,6 +132,8 @@ internal enum SFSessionProperty
         WORKLOAD_IDENTITY_ENTRA_RESOURCE,
         [SFSessionPropertyAttr(required = false, defaultValue = "false")]
         OAUTHENABLESINGLEUSEREFRESHTOKENS,
+        [SFSessionPropertyAttr(required = false, defaultValue = "20")]
+        SERVICE_POINT_CONNECTION_LIMIT,
         [SFSessionPropertyAttr(required = false, defaultValue = "disabled")]
         CERTREVOCATIONCHECKMODE,
         [SFSessionPropertyAttr(required = false, defaultValue = "true")]
@@ -302,6 +304,7 @@ internal static SFSessionProperties ParseConnectionString(string connectionStrin
             ValidateAccountDomain(properties);
             WarnIfHttpUsed(properties);
             ValidateAuthenticatorFlowsProperties(properties);
+            ValidateServicePointConnectionLimit(properties);
             ValidateCrlParameters(properties);
             ValidateTlsParameters(properties);
 
@@ -860,6 +863,23 @@ private static void ValidateFileTransferMaxBytesInMemoryProperty(SFSessionProper
             }
         }
 
+        private static void ValidateServicePointConnectionLimit(SFSessionProperties properties)
+        {
+            if (properties.TryGetValue(SFSessionProperty.SERVICE_POINT_CONNECTION_LIMIT, out var servicePointConnectionLimit))
+            {
+                if (!int.TryParse(servicePointConnectionLimit, out _))
+                {
+                    var errorMessage = $"Invalid value of {SFSessionProperty.SERVICE_POINT_CONNECTION_LIMIT.ToString()} parameter";
+                    logger.Error(errorMessage);
+                    throw new SnowflakeDbException(
+                        new Exception(errorMessage),
+                        SFError.INVALID_CONNECTION_PARAMETER_VALUE,
+                        "",
+                        SFSessionProperty.SERVICE_POINT_CONNECTION_LIMIT.ToString());
+                }
+            }
+        }
+
         private static bool IsRequired(SFSessionProperty sessionProperty, SFSessionProperties properties)
         {
             if (sessionProperty.Equals(SFSessionProperty.PASSWORD))
diff --git a/doc/Connecting.md b/doc/Connecting.md

-Original file line number
+Diff line change
                 false,
                 false,
 ,
 +                20,
                 true,
                 CertRevocationCheckMode.Enabled.ToString(),
                 true,