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我目前在尝试使用 WCF 自托管服务（无 IIS）发送大数据时遇到问题。使用流式传输结果传输 500MB，而我的服务因 System.OutOfMemoryException 而崩溃。是否有可能传输如此大量的数据？

这是我的 WCF 配置：

<system.serviceModel>
<services>
  <service  name="CIService" behaviorConfiguration="CIBehavior">        
    <host>
      <baseAddresses>
        <add baseAddress="net.tcp://localhost:6547/CIService/CIService.svc" />
      </baseAddresses>
    </host>
    <endpoint binding="netTcpBinding" 
        bindingConfiguration="netTcpBindingConfig" 
        behaviorConfiguration="CIBehavior.EndpointBehavior" 
        contract="CIService.ICreatable" />
    <endpoint address="mex" 
        binding="mexHttpBinding" 
        name="mexTcpBinding" 
        contract="IMetadataExchange" />
  </service>
</services>
<serviceHostingEnvironment multippleSiteBindingEnabled="True" />
<bindings>
  <netTcpBinding>
    <binding name="netTcpBindingConfig" closeTimeout="00:01:00" openTimeout="00:01:00" 
        receiveTimeout="01:00:00" sendTimeout="00:10:00" 
        hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxConnections="10"
        maxBufferSize="2147483647" maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647" 
        transferMode="Streamed">
      <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647"
        maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
    </binding>
  </netTcpBinding>
</bindings>

<behaviors>
  <serviceBehaviors>
    <behavior name="CIBehavior">
      <serviceMetadata httpGetEnabled="False" />
      <serviceDebug includeExceptionDetailInFaults="true" />
      <serviceThrottling maxConcurrentCalls="200"  maxConcurrentInstances="2147483647" maxConcurrentSessions="100" />
      <dataContractSerializer maxItemsInObjectGraph="2147483647"/>
    </behavior>
  </serviceBehaviors>
  <endpointBehavior>
    <behavior name="CIBehavior.EndpointBehavior">
      <dataContractSerializer maxItemsInObjectGraph="2147483647" />
    </behavior>
  </endpointBehavior>
</behaviors>
</system.serviceModel>

我的客户端配置：

<system.serviceModel>
<bindings>
  <netTcpBinding>
    <binding name="NetTcpBinding_ICreatable" 
             closeTimeout="00:01:00" openTimeout="00:01:00" 
             receiveTimeout="01:00:00" sendTimeout="00:10:00" 
             transactionFlow="false" 
             transferMode="Streamed" 
             transactionProtocol="OleTransactions" 
             hostNameComparisonMode="StrongWildcard" 
             listenBacklog="10" 
             maxBufferPoolSize="2147483647" 
             maxBufferSize="2147483647" 
             maxConnections="10"
             maxReceivedMessageSize ="2147483647">
      <readerQuotas
        maxDepth="2147483647" 
        maxStringContentLength="2147483647" 
        maxArrayLength="2147483647" 
        maxBytesPerRead="2147483647" 
        maxNameTableCharCount="2147483647" />
      <reliableSession ordered="true" inactivityTimeout="00:10:00" anabled="false" />
    </binding>
  </netTcpBinding>
</bindings>
<client>
  <endpoint name="NetTcpBinding_ICreatable" 
      address="net.tcp://localhost:6547/CIService/CIService.svc" 
      binding="netTcpBinding" 
      bindingConfiguration="NetTcpBinding_ICreatable" 
      behaviorConfiguration="CIBehavior.EndpointBehavior" 
      contract="ICreatable" />
</client>
<behaviors>
  <endpointBehavior>
    <behavior name="CIBehavior.EndpointBehavior">
      <dataContractSerializer maxItemsInObjectGraph="2147483647" />
    </behavior>
  </endpointBehavior>
</behaviors>
</system.serviceModel>
4

1 回答 1

48

您不需要将maxBufferSize或maxBufferPoolSize设置得如此之高，这些可能会导致您的内存不足异常。默认值应该没问题。

查看MSDN 上的大数据和流式传输，特别是大数据的特殊安全注意事项部分，这段文字很重要

MaxBufferSize 属性是约束 WCF 缓冲的内存所必需的。流式传输时将其设置为安全值（或保持默认值）很重要。例如，假设您的服务必须接收最大为 4 GB 的文件并将它们存储在本地磁盘上。还假设您的内存受到限制，您一次只能缓冲 64 KB 的数据。然后将 MaxReceivedMessageSize 设置为 4 GB，将 MaxBufferSize 设置为 64 KB。此外，在您的服务实现中，您必须确保仅从 64 KB 块中的传入流中读取，并且在前一个块写入磁盘并从内存中丢弃之前不要读取下一个块。

我整理了一个非常简单的示例，将数据从自托管服务流式传输到控制台客户端。为了保持帖子简短，我只添加了服务器代码和客户端的一部分。

服务合同

using System.IO;
using System.ServiceModel;

namespace Service
{
    [ServiceContract]
    public interface IStream
    {
        [OperationContract]
        Stream GetLargeObject();
    }
}

服务实现

using System;
using System.IO;
using System.ServiceModel;

namespace Service
{
   [ServiceBehavior]
   public class StreamService : IStream
   {
       public Stream GetLargeObject()
       {
           // Add path to a big file, this one is 2.5 gb
           string filePath = Path.Combine(Environment.CurrentDirectory, "C:\\Temp\\BFBC2_PC_Client_R11_795745_Patch.exe");

        try
        {
            FileStream imageFile = File.OpenRead(filePath);
            return imageFile;
        }
        catch (IOException ex)
        {
            Console.WriteLine(String.Format("An exception was thrown while trying to open file {0}", filePath));
            Console.WriteLine("Exception is: ");
            Console.WriteLine(ex.ToString());
            throw;
        }
    }
 }
}

服务主体

using System;
using System.ServiceModel;

namespace Service
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                using (var serviceHost = new ServiceHost(typeof(StreamService)))
                {
                    serviceHost.Open();

                    Console.WriteLine("Press Any Key to end");
                    Console.ReadKey();
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }
    }
}

服务 app.config

<?xml version="1.0"?>
<configuration>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
  </startup>

  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior name="StreamServiceBehavior">
          <serviceMetadata httpGetEnabled="True" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <bindings>
      <netTcpBinding>
        <binding name="NewBinding0" transferMode="Streamed"/>
      </netTcpBinding>
    </bindings>
    <services>
      <service behaviorConfiguration="StreamServiceBehavior" name="Service.StreamService">
        <endpoint address="net.tcp://localhost:9000/streamserver" binding="netTcpBinding"
          bindingConfiguration="NewBinding0" bindingName="" contract="Service.IStream" />
        <endpoint address="mex" binding="mexHttpBinding"
          contract="IMetadataExchange" />
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8080/StreamService" />
          </baseAddresses>
        </host>
      </service>
    </services>
  </system.serviceModel>
</configuration>

启动服务，可能需要在管理员账户下运行才能打开套接字。创建客户端控制台应用程序并使用 url http://localhost:8080 / StreamService 添加服务引用，使用 Service 作为生成客户端的命名空间。

客户端主

using System;
using System.IO;
using Client.Service;

namespace Client
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                using (StreamClient streamClient = new StreamClient())
                {
                    streamClient.Open();

                    using (FileStream fileStream = new FileStream("c:\\temp\\bigfile.exe",FileMode.Create))
                    {
                        streamClient.GetLargeObject().CopyTo(fileStream);    
                    }
                }

                Console.WriteLine("Press any key to end");
                Console.ReadKey();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
            }
        }
    }
}

生成的客户端配置文件需要稍作修改，增加receiveTimeout并设置maxReceivedMessageSize="4294967295"

<system.serviceModel>
    <bindings>
        <netTcpBinding>
            <binding name="NetTcpBinding_IStream" closeTimeout="00:01:00"
                openTimeout="00:01:00" receiveTimeout="00:30:00" sendTimeout="00:01:00"
                transactionFlow="false" transferMode="Streamed" transactionProtocol="OleTransactions"
                hostNameComparisonMode="StrongWildcard" listenBacklog="10"
                maxBufferPoolSize="524288" maxBufferSize="65536" maxConnections="10"
                maxReceivedMessageSize="4294967295">
                <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
                    maxBytesPerRead="4096" maxNameTableCharCount="16384" />
                <reliableSession ordered="true" inactivityTimeout="00:10:00"
                    enabled="false" />
                <security mode="Transport">
                    <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign" />
                    <message clientCredentialType="Windows" />
                </security>
            </binding>
        </netTcpBinding>
    </bindings>
    <client>
        <endpoint address="net.tcp://localhost:9000/streamserver" binding="netTcpBinding"
            bindingConfiguration="NetTcpBinding_IStream" contract="Service.IStream"
            name="NetTcpBinding_IStream">

        </endpoint>
    </client>
</system.serviceModel>

启动服务，然后启动客户端。它将毫无问题地流式传输一个大文件。

于 2013-02-04T22:24:10.473 回答