我的ASP.NET 4.0生产应用程序遇到了重新发生的问题，导致网站因超时错误而无法响应。
以下是该应用程序的简要概述。该应用程序驻留在3台服务器上; Web服务器，应用程序服务器和运行SQL Server 2008的数据库服务器。所有服务器都在Windows Server 2008上运行.Web服务器驻留在公共域中。应用服务器驻留在DMZ中，通过端口80和443通过WCF在Web服务器之间进行开放式通信。数据库服务器驻留在私有域中，通过端口1433与应用服务器进行开放式通信。该应用程序已经生产了一段时间，并且只在上周经常遇到这些问题。没有代码更改，托管服务提供商表示最近没有对服务器进行任何更改。
在Web服务器上，应用程序遇到下面发布的错误（错误1）。快速修复解决方案是重新启动应用服务器IIS进程，但是，这是一个反复出现的问题，并导致业务所有者出现重大中断。
应用程序的DAL使用Enterprise Library v4.1打开与数据库的连接。我已经包含了2个代码片段，负责启动呼叫（代码1和代码2）。以各种其他方法重复该方法。 ExecuteReader方法可能没有正确关闭连接吗？没有覆盖允许我指定ConnectionBehavior来关闭连接的方法。
我们执行了SQL配置文件分析，并确定没有与数据库的延迟打开连接。
在研究问题时，有人建议企业库可能存在连接未被妥善处理的错误，但是在帖子上没有验证。如何确定问题的原因？或者解决问题的适当行动方案是什么？我可以增加池大小，但这似乎只是一个临时解决方案。
错误1：
***System.ServiceModel.FaultException: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached. at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at Microsoft.Practices.EnterpriseLibrary.Data.Database.GetNewOpenConnection() at Microsoft.Practices.EnterpriseLibrary.Data.Database.GetOpenConnection(Boolean disposeInnerConnection) at Microsoft.Practices.EnterpriseLibrary.Data.Database.ExecuteReader(DbCommand command) at Microsoft.Practices.EnterpriseLibrary.Data.Database.ExecuteReader(String storedProcedureName, Object[] parameterValues) at CityStoreDAL.NavigationProvider.GetNavigator(Int32 navigatorID) in c:\TFS\CityStore\DEV\SRC\CityStoreDAL\NavigationProvider.cs:line 41 at CityStoreBLL.Navigation.GetNavigator(Int32 navigatorID) in c:\TFS\CityStore\DEV\SRC\CityStoreBLL\Navigation.cs:line 15 at CityStoreService.CityStoreService.GetNavigator(Int32 navigato rID) in c:\TFS\CityStore\DEV\SRC\CityStoreService\Navigation.cs:line 21 at SyncInvokeGetNavigator(Object , Object[] , Object[] ) at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs) at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc) at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)***
Generated: Wed, 12 Nov 2014 19:40:22 GMT
System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.ServiceModel.FaultException: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached. at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
at System.Data.SqlClient.SqlConnection.Open()
at Microsoft.Practices.EnterpriseLibrary.Data.Database.GetNewOpenConnection()
at Microsoft.Practices.EnterpriseLibrary.Data.Database.GetOpenConnection(Boolean disposeInnerConnection)
at Microsoft.Practices.EnterpriseLibrary.Data.Database.ExecuteReader(DbCommand command)
at Microsoft.Practices.EnterpriseLibrary.Data.Database.ExecuteReader(String storedProcedureName, Object[] parameterValues)
at CityStoreDAL.NavigationProvider.GetNavigator(Int32 navigatorID) in c:\TFS\CityStore\DEV\SRC\CityStoreDAL\NavigationProvider.cs:line 41
at CityStoreBLL.Navigation.GetNavigator(Int32 navigatorID) in c:\TFS\CityStore\DEV\SRC\CityStoreBLL\Navigation.cs:line 15
at CityStoreService.CityStoreService.GetNavigator(Int32 navigatorID) in c:\TFS\CityStore\DEV\SRC\CityStoreService\Navigation.cs:line 21
at SyncInvokeGetNavigator(Object , Object[] , Object[] )
at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)
Server stack trace:
at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
Exception rethrown at [0]:
at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
at CityStoreWeb.CityStoreServiceReference.INavigation.GetNavigator(Int32 navigatorID)
at CityStoreWeb.Product.<>c__DisplayClass1.<BindCategoryMenuAndInfo>b__0(INavigation proxy) in c:\TFS\CityStore\DEV\SRC\CityStoreWeb\Product.aspx.cs:line 73
at CityStoreWeb.Common.Service'1.Use(UseServiceDelegate'1 codeBlock) in c:\TFS\CityStore\DEV\SRC\CityStoreWeb\Common\Utils.cs:line 243
at CityStoreWeb.Product.BindCategoryMenuAndInfo(Int32 navigatorID) in c:\TFS\CityStore\DEV\SRC\CityStoreWeb\Product.aspx.cs:line 71
at CityStoreWeb.Product.SetupPage(Int32 navigatorID, Int32 categoryID, Int32 productID) in c:\TFS\CityStore\DEV\SRC\CityStoreWeb\Product.aspx.cs:line 64
at CityStoreWeb.Product.Page_Load(Object sender, EventArgs e) in c:\TFS\CityStore\DEV\SRC\CityStoreWeb\Product.aspx.cs:line 37
at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
at System.Web.UI.Control.OnLoad(EventArgs e)
at CityStoreWeb.Common.BasePage.OnLoad(EventArgs e) in c:\TFS\CityStore\DEV\SRC\CityStoreWeb\Common\BasePage.cs:line 26
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
--- End of inner exception stack trace ---
at System.Web.UI.Page.HandleError(Exception e)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.product_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
代码1：
public static NavigatorEntity GetNavigator(int navigatorID)
{
Database db = DatabaseFactory.CreateDatabase();
object[] spParams;
spParams = new object[1];
spParams[0] = navigatorID;
using (IDataReader reader = db.ExecuteReader("GetNavigator", spParams))
{
if (reader == null)k
{
throw new ArgumentNullException("reader");
}
NavigatorEntity myNav = null;
if (reader.Read())
{
myNav = GetNavigatorEntityFromReader(reader);
}
if (myNav != null)
{
reader.NextResult();
myNav.Categories = GetCategoriesCollectionFromReader(reader);
reader.NextResult();
myNav.RecommendedProducts =
ProductProvider.GetRecommendedProductCollectionFromReader(reader, false);
}
return myNav;
}
}
代码2：
public static List<NavigatorEntity> GetNavigatorsAll()
{
Database db = DatabaseFactory.CreateDatabase();
using (IDataReader myReader = db.ExecuteReader("GetNavigatorsAll"))
{
return GetNavigatorCollectionFromReader(myReader);
}
}
private static List<NavigatorEntity> GetNavigatorCollectionFromReader(IDataReader reader)
{
List<NavigatorEntity> navigators = new List<NavigatorEntity>();
while (reader.Read())
{
navigators.Add(GetNavigatorEntityFromReader(reader));
}
return navigators;
}
更新
显然，问题不在于ASP.NET错误中引用的任何方法。他们抛出一个异常，因为到达它们时，问题（耗尽的连接池）已经发生，并且会在任何打开新连接的进行方法上抛出异常。
在分析了数据访问层中的所有代码之后，我确定了一些未正确使用using语句的rouge方法，从而使池中的开放连接保持累积。在隔离方法并使用性能监视器观察NumberOfPooledConnections之后，我确认这些方法应该受到责备。
修复方法是将rouge方法包装在适当的using语句中。
导致问题的方法之一：
public static List<TaxCodeEntity> CMSGetTaxCodes()
{
Database db = DatabaseFactory.CreateDatabase();
return GetTaxCodeCollectionFromReader(db.ExecuteReader("CMS_GetTaxCodes"));
}
修复：
public static List<TaxCodeEntity> CMSGetTaxCodes()
{
Database db = DatabaseFactory.CreateDatabase();
using (DbCommand dbCmd = db.GetStoredProcCommand("CMS_GetTaxCodes"))
{
using (IDataReader myReader = db.ExecuteReader(dbCmd))
{
return GetTaxCodeCollectionFromReader(myReader);
}
}
}
答案 0 :(得分：2)
一旦Reader打开，我可以看到许多动作发生。如果在依赖函数上引发任何异常，例如：myNav.Categories = GetCategoriesCollectionFromReader（reader）;可以让读者保持开放。安全方专门关闭读者。像这样：
public static NavigatorEntity GetNavigator(int navigatorID)
{
Database db = DatabaseFactory.CreateDatabase();
object[] spParams;
spParams = new object[1];
spParams[0] = navigatorID;
using (IDataReader reader = db.ExecuteReader("GetNavigator", spParams))
{
try
{
if (reader == null)
{
throw new ArgumentNullException("reader");
}
NavigatorEntity myNav = null;
if (reader.Read())
{
myNav = GetNavigatorEntityFromReader(reader);
}
if (myNav != null)
{
reader.NextResult();
myNav.Categories = GetCategoriesCollectionFromReader(reader);
reader.NextResult();
myNav.RecommendedProducts =
ProductProvider.GetRecommendedProductCollectionFromReader(reader, false);
}
return myNav;
}
catch
{
}
finally
{
reader.Close();
}
}
}
还要关注你的sql server：
从sys.sysprocesses中选择DB_NAME（dbid），COUNT（dbid），loginame，其中dbid＆gt; 0 GROUP BY dbid，loginame
答案 1 :(得分：1)
调试的一种方法是将性能计数器添加到跟踪/日志/异常处理。 NumberOfActiveConnectionPoolGroups，NumberOfActiveConnectionPools和NumberOfPooledConnections可能是调试问题所需的计数器值。
MSDN Link