我遇到了一个仅出现在一台服务器上的间歇性问题，并导致所有 MVC 页面无法加载并显示错误“已添加具有相同密钥的项目”。
重新启动应用程序池可以解决问题，但在此之前，加载任何 mvc 页面都会引发以下异常：
Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 10/11/2012 08:09:24
Event time (UTC): 10/11/2012 08:09:24
Event ID: d76264aedc4241d4bce9247692510466
Event sequence: 6407
Event occurrence: 30
Event detail code: 0
Application information:
Application domain: /LM/W3SVC/21/ROOT-2-129969647741292058
Trust level: Full
Application Virtual Path: /
Application Path: d:\websites\SiteAndAppPoolName\
Machine name: UKSERVER
Process information:
Process ID: 6156
Process name: w3wp.exe
Account name: IIS APPPOOL\SiteAndAppPoolName
Exception information:
Exception type: ArgumentException
Exception message: An item with the same key has already been added.
Server stack trace:
at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
at System.Linq.Enumerable.ToDictionary[TSource,TKey,TElement](IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer)
at System.Web.WebPages.Scope.WebConfigScopeDictionary.<>c__DisplayClass4.<.ctor>b__0()
at System.Lazy`1.CreateValue()
Exception rethrown at [0]:
at System.Lazy`1.get_Value()
at System.Web.WebPages.Scope.WebConfigScopeDictionary.TryGetValue(Object key, Object& value)
at System.Web.Mvc.ViewContext.ScopeGet[TValue](IDictionary`2 scope, String name, TValue defaultValue)
at System.Web.Mvc.ViewContext.ScopeCache.Get(IDictionary`2 scope, HttpContextBase httpContext)
at System.Web.Mvc.ViewContext.GetClientValidationEnabled(IDictionary`2 scope, HttpContextBase httpContext)
at System.Web.Mvc.Html.FormExtensions.FormHelper(HtmlHelper htmlHelper, String formAction, FormMethod method, IDictionary`2 htmlAttributes)
at System.Web.Mvc.Html.FormExtensions.BeginForm(HtmlHelper htmlHelper, String actionName, String controllerName)
at ASP._Page_Views_Dashboard_Functions_BookingQuickLookup_cshtml.Execute() in d:\Websites\SiteAndAppPoolName\Views\Dashboard\Functions\BookingQuickLookup.cshtml:line 3
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
at ASP._Page_Views_Dashboard_Functions_cshtml.Execute() in d:\Websites\SiteAndAppPoolName\Views\Dashboard\Functions.cshtml:line 5
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.Html.RenderPartialExtensions.RenderPartial(HtmlHelper htmlHelper, String partialViewName, Object model)
at ASP._Page_Views_Dashboard_Index_cshtml.Execute() in d:\Websites\SiteAndAppPoolName\Views\Dashboard\Index.cshtml:line 9
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)
at System.Web.Mvc.Controller.ExecuteCore()
at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext)
at System.Web.Mvc.MvcHandler.<>c__DisplayClass6.<>c__DisplayClassb.<BeginProcessRequest>b__5()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.<MakeVoidDelegate>b__0()
at System.Web.Mvc.MvcHandler.<>c__DisplayClasse.<EndProcessRequest>b__d()
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Request information:
Request URL: http://SiteAndAppPoolName.spawtz.com/Dashboard
Request path: /Dashboard
User host address: 86.164.135.41
User:
Is authenticated: False
Authentication Type:
Thread account name: IIS APPPOOL\SiteAndAppPoolName
Thread information:
Thread ID: 17
Thread account name: IIS APPPOOL\SiteAndAppPoolName
Is impersonating: False
Stack trace: at System.Lazy`1.get_Value()
at System.Web.WebPages.Scope.WebConfigScopeDictionary.TryGetValue(Object key, Object& value)
at System.Web.Mvc.ViewContext.ScopeGet[TValue](IDictionary`2 scope, String name, TValue defaultValue)
at System.Web.Mvc.ViewContext.ScopeCache.Get(IDictionary`2 scope, HttpContextBase httpContext)
at System.Web.Mvc.ViewContext.GetClientValidationEnabled(IDictionary`2 scope, HttpContextBase httpContext)
at System.Web.Mvc.Html.FormExtensions.FormHelper(HtmlHelper htmlHelper, String formAction, FormMethod method, IDictionary`2 htmlAttributes)
at System.Web.Mvc.Html.FormExtensions.BeginForm(HtmlHelper htmlHelper, String actionName, String controllerName)
at ASP._Page_Views_Dashboard_Functions_BookingQuickLookup_cshtml.Execute() in d:\Websites\SiteAndAppPoolName\Views\Dashboard\Functions\BookingQuickLookup.cshtml:line 3
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
at ASP._Page_Views_Dashboard_Functions_cshtml.Execute() in d:\Websites\SiteAndAppPoolName\Views\Dashboard\Functions.cshtml:line 5
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.Html.RenderPartialExtensions.RenderPartial(HtmlHelper htmlHelper, String partialViewName, Object model)
at ASP._Page_Views_Dashboard_Index_cshtml.Execute() in d:\Websites\SiteAndAppPoolName\Views\Dashboard\Index.cshtml:line 9
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)
at System.Web.Mvc.Controller.ExecuteCore()
at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext)
at System.Web.Mvc.MvcHandler.<>c__DisplayClass6.<>c__DisplayClassb.<BeginProcessRequest>b__5()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.<MakeVoidDelegate>b__0()
at System.Web.Mvc.MvcHandler.<>c__DisplayClasse.<EndProcessRequest>b__d()
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Custom event details:
如前所述，在重新启动应用程序池之前，每个 MVC 操作都会引发此错误，并且该错误似乎发生在System.Web.WebPages.Scope.WebConfigScopeDictionary.TryGetValue(Object key, Object& value)
有没有人见过这个问题？它只发生在此服务器上，在服务器上的任何应用程序池上（不限于此），并且应用程序池重新启动对其进行排序。
非常感谢任何帮助。
干杯，
马修
编辑：
这是 web.config 文件：
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
<section name="listManagers" type="Spawtz.ListManagersConfigSection, SpawtzConfiguration" />
<sectionGroup name="elmah">
<section name="security" requirePermission="false" type="Elmah.SecuritySectionHandler, Elmah" />
<section name="errorLog" requirePermission="false" type="Elmah.ErrorLogSectionHandler, Elmah" />
<section name="errorMail" requirePermission="false" type="Elmah.ErrorMailSectionHandler, Elmah" />
<section name="errorFilter" requirePermission="false" type="Elmah.ErrorFilterSectionHandler, Elmah" />
</sectionGroup>
<sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
<section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
</sectionGroup>
</configSections>
<appSettings>
<add key="ConnectionString" value="cs" />
</appSettings>
<log4net>
<appender name="SmtpAppender" type="log4net.Appender.SmtpAppender">
<to value="spawtzerror@spawtz.com" />
<from value="matthew@spawtz.com" />
<subject value="Error in SiteAndAppPoolName Spawtz Application" />
<smtpHost value="127.0.0.1" />
<bufferSize value="1" />
<lossy value="true" />
<evaluator type="log4net.spi.LevelEvaluator">
<threshold value="WARN" />
</evaluator>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="User: %X{User} %n%d [%t] %-5p %c [%x] - %m%n%n%n" />
</layout>
</appender>
<root>
</root>
<logger name="Error">
<level value="ERROR" />
<appender-ref ref="SmtpAppender" />
</logger>
</log4net>
<system.web>
<!-- DYNAMIC DEBUG COMPILATION
Set compilation debug="true" to enable ASPX debugging. Otherwise, setting this value to
false will improve runtime performance of this application.
Set compilation debug="true" to insert debugging symbols (.pdb information)
into the compiled page. Because this creates a larger file that executes
more slowly, you should set this value to true only when debugging and to
false at all other times. For more information, refer to the documentation about
debugging ASP.NET files.
-->
<compilation defaultLanguage="c#" debug="true" targetFramework="4.0">
<assemblies>
<add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.Helpers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Web.WebPages, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add assembly="System.Data.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
</assemblies>
</compilation>
<!-- CUSTOM ERROR MESSAGES
Set customErrors mode="On" or "RemoteOnly" to enable custom error messages, "Off" to disable.
Add <error> tags for each of the errors you want to handle.
"On" Always display custom (friendly) messages.
"Off" Always display detailed ASP.NET error information.
"RemoteOnly" Display custom (friendly) messages only to users not running
on the local Web server. This setting is recommended for security purposes, so
that you do not display application detail information to remote clients.
-->
<!--<customErrors mode="On" defaultRedirect="Error.aspx" />-->
<customErrors mode="Off" />
<!-- AUTHENTICATION
This section sets the authentication policies of the application. Possible modes are "Windows",
"Forms", "Passport" and "None"
"None" No authentication is performed.
"Windows" IIS performs authentication (Basic, Digest, or Integrated Windows) according to
its settings for the application. Anonymous access must be disabled in IIS.
"Forms" You provide a custom form (Web page) for users to enter their credentials, and then
you authenticate them in your application. A user credential token is stored in a cookie.
"Passport" Authentication is performed via a centralized authentication service provided
by Microsoft that offers a single logon and core profile services for member sites.
-->
<authentication mode="Forms" />
<!-- AUTHORIZATION
This section sets the authorization policies of the application. You can allow or deny access
to application resources by user or role. Wildcards: "*" mean everyone, "?" means anonymous
(unauthenticated) users.
-->
<authorization>
<allow users="*" />
<!-- Allow all users -->
<!-- <allow users="[comma separated list of users]"
roles="[comma separated list of roles]"/>
<deny users="[comma separated list of users]"
roles="[comma separated list of roles]"/>
-->
</authorization>
<!-- APPLICATION-LEVEL TRACE LOGGING
Application-level tracing enables trace log output for every page within an application.
Set trace enabled="true" to enable application trace logging. If pageOutput="true", the
trace information will be displayed at the bottom of each page. Otherwise, you can view the
application trace log by browsing the "trace.axd" page from your web application
root.
-->
<trace enabled="false" requestLimit="10" pageOutput="false" traceMode="SortByTime" localOnly="true" />
<!-- SESSION STATE SETTINGS
By default ASP.NET uses cookies to identify which requests belong to a particular session.
If cookies are not available, a session can be tracked by adding a session identifier to the URL.
To disable cookies, set sessionState cookieless="true".
-->
<sessionState mode="InProc" stateConnectionString="tcpip=127.0.0.1:42424" sqlConnectionString="data source=127.0.0.1;Trusted_Connection=yes" cookieless="false" timeout="20" />
<!-- GLOBALIZATION
This section sets the globalization settings of the application.
-->
<globalization requestEncoding="utf-8" responseEncoding="utf-8" />
<pages validateRequest="false" controlRenderingCompatibilityVersion="4.0" clientIDMode="AutoID" pageParserFilterType="System.Web.Mvc.ViewTypeParserFilter, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" pageBaseType="System.Web.Mvc.ViewPage, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" userControlBaseType="System.Web.Mvc.ViewUserControl, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
<namespaces>
<add namespace="System.Web.Helpers" />
<add namespace="System.Web.Mvc" />
<add namespace="System.Web.Mvc.Ajax" />
<add namespace="System.Web.Mvc.Html" />
<add namespace="System.Web.Routing" />
<add namespace="System.Web.WebPages" />
<add namespace="System.Linq" />
<add namespace="System.Collections.Generic" />
<add namespace="SpawtzController.ViewModels" />
<add namespace="SpawtzController" />
</namespaces>
<controls>
<add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" namespace="System.Web.Mvc" tagPrefix="mvc" />
</controls>
</pages>
<httpHandlers>
<add path="*" verb="/Views/*" type="System.Web.HttpNotFoundHandler" />
<add verb="*" path="*.mvc" validate="false" type="System.Web.Mvc.MvcHttpHandler, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<add path="Telerik.Web.UI.WebResource.axd" verb="*" type="Telerik.Web.UI.WebResource, Telerik.Web.UI" validate="false" />
<add path="Telerik.Web.UI.DialogHandler.aspx" type="Telerik.Web.UI.DialogHandler" verb="*" validate="false" />
<add verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" />
</httpHandlers>
<httpModules>
<add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" />
<add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" />
<add name="FixIIS5xWildcardMapping" type="Elmah.FixIIS5xWildcardMappingModule, Elmah" />
</httpModules>
</system.web>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
<bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="3.0.0.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="MvcContrib" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-2.0.34.0" newVersion="2.0.34.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Castle.Core" publicKeyToken="407dd0808d44fbdc" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-2.5.1.0" newVersion="2.5.1.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Castle.Windsor" publicKeyToken="407dd0808d44fbdc" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-2.5.1.0" newVersion="2.5.1.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<system.web.webPages.razor>
<host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<pages pageBaseType="System.Web.Mvc.WebViewPage">
<namespaces>
<add namespace="System.Web.Mvc" />
<add namespace="System.Web.Mvc.Ajax" />
<add namespace="System.Web.Mvc.Html" />
<add namespace="System.Web.Routing" />
</namespaces>
</pages>
</system.web.webPages.razor>
<connectionStrings>
<add name="Spawtz" connectionString="cs" />
</connectionStrings>
<elmah>
<errorLog type="Elmah.SqlErrorLog, Elmah" connectionStringName="Spawtz" applicationName="SiteAndAppPoolName" />
<security allowRemoteAccess="yes" />
<errorFilter>
<test>
<equal binding="HttpStatusCode" value="404" type="Int32" />
</test>
</errorFilter>
</elmah>
<system.webServer>
<validation validateIntegratedModeConfiguration="false" />
<modules runAllManagedModulesForAllRequests="true">
<remove name="UrlRoutingHandler" />
<remove name="ErrorLog" />
<remove name="ErrorMail" />
<add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" preCondition="managedHandler" />
<add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" preCondition="managedHandler" />
<add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" />
</modules>
<handlers>
<remove name="UrlRoutingHandler" />
<remove name="elmah" />
<remove name="BlockViewHandler" />
<add name="BlockViewHandler" path="/Views/*" verb="*" preCondition="integratedMode" type="System.Web.HttpNotFoundHandler" />
<add name="Mvc" path="*" verb="*" modules="IsapiModule" scriptProcessor="C:\Windows\Microsoft.NET\Framework64\v2.0.50727\aspnet_isapi.dll" resourceType="Unspecified" requireAccess="None" preCondition="classicMode,runtimeVersionv2.0,bitness64" />
<add name="Telerik_Web_UI_DialogHandler_aspx" verb="*" preCondition="integratedMode" path="Telerik.Web.UI.DialogHandler.aspx" type="Telerik.Web.UI.DialogHandler" />
<add name="elmah" verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" />
<add name="Telerik_Web_UI_WebResource_axd" path="Telerik.Web.UI.WebResource.axd" verb="*" type="Telerik.Web.UI.WebResource, Telerik.Web.UI" />
</handlers>
<defaultDocument>
<files>
<remove value="iisstart.htm" />
<remove value="index.html" />
<remove value="index.htm" />
<remove value="Default.asp" />
<remove value="Default.htm" />
</files>
</defaultDocument>
</system.webServer>
<location path="elmah.axd">
<system.web>
<authorization>
<allow roles="Administrators" />
<deny users="?" />
</authorization>
</system.web>
</location>
</configuration>
再次编辑：
好的，既然上面的问题似乎没有简单的答案，也许这个问题有一个答案：我可以以某种方式配置IIS在指定时间段内遇到指定数量的错误后自动回收应用程序池吗？我知道我可以启用快速故障保护，但这不是我所追求的，因为那时我将不得不手动重新启动应用程序池。作为一种解决方法（阅读：hack ...），我想修复它，以便它在连续出现大量错误时自行重启。那是可行的吗？
再编辑一次
好的，这个错误今天早上也发生在另一台服务器上，所以似乎不仅仅是服务器配置导致它。也许这是我的代码中的某些东西，但我对如何诊断它感到困惑，因为我无法复制它也无法调试它......似乎我还有更多的调查要做。