我们有一个安装了WCF作为Web角色的Azure云服务。该服务使用实体框架在线连接到azure db。该服务由WPF客户端使用，该客户端使用公司代理连接到Web。
有时客户收到错误：＆＃34;服务器太忙了。＆＃34; ，内部异常是＆＃34; HTTP 503 - 服务不可用＆＃34;。
为了调查此错误，我尝试通过远程桌面连接云服务的VM：
在IIS上我改变了：
我还向WCF添加了遥测功能，以记录所有异常和一些请求。 没有任何帮助，错误继续随机出现。
今天我在托管WCF的服务器上安装了WireShark并捕获了入站流量。 即使没有响应代码请求失败的迹象！= 200，所有请求都是＆＃34; http1.1 200 OK。＆＃34;
前几天我在家工作并经常使用WPF客户端（不使用代理），错误从未出现过。
可能与我们在工作中使用的公司代理相关吗？
在客户端和WCF配置下面：
WPF客户端配置：
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
</configSections>
<appSettings>
<add key="ClientSettingsProvider.ServiceUri" value="" />
</appSettings>
</connectionStrings>
</entityFramework>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
</startup>
<system.serviceModel>
<bindings>
<customBinding>
<binding name="largedata" closeTimeout="00:21:00" openTimeout="00:20:00" receiveTimeout="00:20:00" sendTimeout="00:20:00">
<security authenticationMode="UserNameOverTransport" messageSecurityVersion="WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10" allowInsecureTransport="true" />
<binaryMessageEncoding maxReadPoolSize="2147483647" maxWritePoolSize="2147483647" compressionFormat="GZip">
<readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
</binaryMessageEncoding>
<httpTransport bypassProxyOnLocal="True"
authenticationScheme="Basic"
useDefaultWebProxy="True"
proxyAuthenticationScheme="Basic"
keepAliveEnabled="True"
maxBufferPoolSize="2147483647"
maxReceivedMessageSize="2147483647"
maxBufferSize="2147483647" />
</binding>
</customBinding>
</bindings>
<client>
<endpoint address="http://wcfadress/Data.svc" binding="customBinding" bindingConfiguration="largedata" contract="DataService.DataService" name="largedata" />
</client>
</system.serviceModel>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.Edm" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.6.4.0" newVersion="5.6.4.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.Services.Client" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.6.4.0" newVersion="5.6.4.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.OData" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.6.4.0" newVersion="5.6.4.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<system.net>
<defaultProxy enabled="true" useDefaultCredentials="true">
<proxy proxyaddress="http://proxyadress" ></proxy>
</defaultProxy>
<settings>
<servicePointManager expect100Continue="false" />
</settings>
</system.net>
<system.web>
<membership defaultProvider="ClientAuthenticationMembershipProvider">
<providers>
<add name="ClientAuthenticationMembershipProvider" type="System.Web.ClientServices.Providers.ClientFormsAuthenticationMembershipProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" serviceUri="" />
</providers>
</membership>
<roleManager defaultProvider="ClientRoleProvider" enabled="true">
<providers>
<add name="ClientRoleProvider" type="System.Web.ClientServices.Providers.ClientRoleProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" serviceUri="" cacheTimeout="86400" />
</providers>
</roleManager>
</system.web>
</configuration>
WCF配置
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<system.diagnostics>
<trace>
<listeners>
<add type="Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics, Version=2.6.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="AzureDiagnostics">
<filter type="" />
</add>
</listeners>
</trace>
<sources>
<source name="System.ServiceModel" switchValue="Critical, Error, Warning" propagateActivity="true">
<listeners>
<add name="traceListener" type="System.Diagnostics.XmlWriterTraceListener" initializeData="c:\temp\TracesWCF.svclog" />
</listeners>
</source>
</sources>
</system.diagnostics>
<connectionStrings>
<add name="Clio" providerName="System.Data.EntityClient" connectionString="metadata=res://*/DataMadel.csdl|res://*/DataMadel.ssdl|res://*/DataMadel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=*****;Initial Catalog=*****;Language=Italian;Integrated Security=False;*****;Password=*****;Connection Timeout=600;MultipleActiveResultSets=True;Encrypt=True;Min Pool Size=20;Max Pool Size=50;TrustServerCertificate=False"" />
</connectionStrings>
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
</entityFramework>
<appSettings>
<add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" />
</appSettings>
<system.web>
<compilation debug="true" targetFramework="4.5" />
<httpRuntime targetFramework="4.5" maxRequestLength="202400" />
<httpModules>
<add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Extensibility.Web.RequestTracking.WebRequestTrackingModule, Microsoft.ApplicationInsights.Extensibility.Web" />
</httpModules>
</system.web>
<system.serviceModel>
<diagnostics>
<messageLogging
logEntireMessage="true"
logMalformedMessages="false"
logMessagesAtServiceLevel="true"
logMessagesAtTransportLevel="true"
maxMessagesToLog="400"
maxSizeOfMessageToLog="6000"/>
</diagnostics>
<bindings>
<customBinding>
<binding name="largedata" closeTimeout="00:21:00" openTimeout="00:20:00" receiveTimeout="00:20:00" sendTimeout="00:50:00">
<security authenticationMode="UserNameOverTransport" messageSecurityVersion="WSSecurity10WSTrustFebruary2005WSSecureConversationFebruary2005WSSecurityPolicy11BasicSecurityProfile10" allowInsecureTransport="true" />
<binaryMessageEncoding maxReadPoolSize="2147483647" maxWritePoolSize="2147483647" compressionFormat="GZip">
<readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647" maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
</binaryMessageEncoding>
<httpTransport maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647" maxBufferSize="2147483647" />
</binding>
</customBinding>
</bindings>
<services>
<service name="ArchivioStorico.Service.DataService" behaviorConfiguration="Auth">
<endpoint address="" binding="customBinding" bindingConfiguration="largedata" contract="ArchivioStorico.Service.DataService" />
<endpoint address="basicHttp" binding="basicHttpBinding" contract="ArchivioStorico.Service.DataService" />
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="Auth">
<!-- To avoid disclosing metadata information, set the values below to false before deployment -->
<serviceMetadata httpGetEnabled="true" httpsGetEnabled="true" />
<!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information -->
<serviceDebug includeExceptionDetailInFaults="true" />
<dataContractSerializer maxItemsInObjectGraph="2147483647" />
<serviceThrottling maxConcurrentCalls="1300" maxConcurrentSessions="1300" maxConcurrentInstances="1300"></serviceThrottling>
<serviceCredentials>
<userNameAuthentication userNamePasswordValidationMode="Custom" customUserNamePasswordValidatorType="ArchivioStorico.Service.CustomValidator.CustomUserNameValidator, App_Code" />
</serviceCredentials>
</behavior>
</serviceBehaviors>
<endpointBehaviors>
<behavior>
<dataContractSerializer maxItemsInObjectGraph="2147483647" />
</behavior>
</endpointBehaviors>
</behaviors>
<protocolMapping>
<add binding="basicHttpsBinding" scheme="https" />
<add binding="basicHttpBinding" scheme="http" />
<add binding="webHttpBinding" scheme="http" />
</protocolMapping>
<serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
</system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true">
<remove name="ApplicationInsightsWebTracking" />
<add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Extensibility.Web.RequestTracking.WebRequestTrackingModule, Microsoft.ApplicationInsights.Extensibility.Web" preCondition="managedHandler" />
</modules>
<!--
To browse web app root directory during debugging, set the value below to true.
Set to false before deployment to avoid disclosing web app folder information.
-->
<directoryBrowse enabled="true" />
<security>
<requestFiltering>
<!--Increase 'maxAllowedContentLength' to needed value: 100mb (value is in bytes)-->
<requestLimits maxAllowedContentLength="204857600" />
</requestFiltering>
</security>
<validation validateIntegratedModeConfiguration="false" />
</system.webServer>
<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.Edm" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.6.4.0" newVersion="5.6.4.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.Services.Client" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.6.4.0" newVersion="5.6.4.0" />
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.Data.OData" publicKeyToken="31bf3856ad364e35" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-5.6.4.0" newVersion="5.6.4.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
<system.net>
<settings>
<servicePointManager expect100Continue="false" />
</settings>
</system.net>
</configuration>