WCF，序列化大量数据时出现内存不足异常

Question

基本上，我从 SQL Server 获取数据。如果我选择所有数据（大约 80000 行），那么我会收到以下错误（接收 100 行工作正常）

Exception of type 'System.OutOfMemoryException' was thrown. <br/>

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. <br/>

Exception Details: System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.

Stack Trace: 

[OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown.]
   System.Text.StringBuilder.ToString() +29
   System.IO.StringWriter.ToString() +14
   System.Net.WebUtility.HtmlEncode(String value) +110
   System.Web.Util.HttpEncoder.HtmlEncode(String value) +54
   System.Web.UI.HtmlControls.HtmlContainerControl.set_InnerText(String value) +24
   PerformanceCompare._Default.Page_Load(Object sender, EventArgs e) in C:\Users\KK33562\Documents\Visual Studio 2010\Projects\TestWebService\PerformanceCompare\Default.aspx.cs:34
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +91
   System.Web.UI.Control.LoadRecursive() +74
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207

Web.config（客户端）

<system.serviceModel>
<behaviors>
  <endpointBehaviors>
    <behavior name="endpointbehaviour">
      <dataContractSerializer maxItemsInObjectGraph="2147483647"/>
    </behavior>
  </endpointBehaviors>
</behaviors>
<bindings>
  <basicHttpBinding>
    <binding name="BasicHttpBinding_IService1" closeTimeout="00:50:00"
      openTimeout="00:50:00" receiveTimeout="00:50:00" sendTimeout="00:50:00"
      allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
      maxBufferSize="2147483647" maxBufferPoolSize="524288" maxReceivedMessageSize="2147483647"
      messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
      useDefaultWebProxy="true">
      <readerQuotas maxDepth="32" maxStringContentLength="2147483647" maxArrayLength="2147483647"
        maxBytesPerRead="4096" maxNameTableCharCount="16384" />
      <security mode="None">
        <transport clientCredentialType="None" proxyCredentialType="None"
          realm="" />
        <message clientCredentialType="UserName" algorithmSuite="Default" />
      </security>
    </binding>
  </basicHttpBinding>
</bindings>
<client>
  <endpoint address="http://localhost:53268/Service1.svc" binding="basicHttpBinding"
    bindingConfiguration="BasicHttpBinding_IService1" contract="WCFService.IService1"
    name="BasicHttpBinding_IService1" behaviorConfiguration="endpointbehaviour" />
</client>
</system.serviceModel>

Web.config（服务器端）

<system.serviceModel>
<behaviors>      
  <serviceBehaviors>
    <behavior name="TestWCF.Service1Behavior">
      <dataContractSerializer maxItemsInObjectGraph="2147483646"/>
      <serviceMetadata httpGetEnabled="true"/>
      <serviceDebug includeExceptionDetailInFaults="true"/>
    </behavior>
  </serviceBehaviors>
</behaviors>
  <services>
    <service name="TestWCF.Service1" behaviorConfiguration="TestWCF.Service1Behavior">
      <endpoint address="" binding="basicHttpBinding" contract="TestWCF.IService1" bindingConfiguration="BasicHttpBinding_IService1">
        <identity>
          <dns value="localhost"/>
        </identity>
      </endpoint>
      <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
    </service>
  </services>    
<bindings>
  <basicHttpBinding>
    <binding name="BasicHttpBinding_IService1" maxBufferSize="2147483647" maxReceivedMessageSize="2147483647" openTimeout="00:50:00" closeTimeout="00:50:00" sendTimeout="00:50:00" receiveTimeout="00:10:00">
      <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647"
        maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
    </binding>
  </basicHttpBinding>
</bindings>
</system.serviceModel>

Answer 1

如果您从服务中返回 80K 行，那么我认为您最好一起摆脱该服务。只需让客户端直接访问数据库，然后他们就可以从数据库中提取他们需要的所有行。

编辑

在不必要的地方引入服务边界是一个非常常见的错误，而且我看到这种错误越来越多。在大多数情况下，让客户端使用 NHibernate 甚至 ADO 以及存储的过程或视图直接调用数据库会更干净。

如果您的客户无法实际看到网络上的数据库，那么您可能需要使用服务。