如何防止WCF服务进入故障状态？

通常,WCF服务托管在ServiceHost中,如果WCF服务失败,则唯一的选择是终止WCF服务并启动新服务.

ServiceHost有一个事件触发器"Faulted",在WCF服务失败时激活:

ServiceHost host = new ServiceHost(new Service.MyService());
host.Faulted += new EventHandler(host_faulted);
host.Open();

可能会导致导致错误的异常,但需要更多工作:

public class ErrorHandler : IErrorHandler
{
    public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
    {

    }

    public bool HandleError(Exception error)
    {
        Console.WriteLine("exception");
        return false;
    }
}

public class ErrorServiceBehavior : IServiceBehavior
{
    public void Validate(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {

    }

    public void AddBindingParameters(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase, Collection endpoints, BindingParameterCollection bindingParameters)
    {

    }

    public void ApplyDispatchBehavior(ServiceDescription serviceDescription, ServiceHostBase serviceHostBase)
    {
        ErrorHandler handler = new ErrorHandler();
        foreach (ChannelDispatcher dispatcher in serviceHostBase.ChannelDispatchers)
        {
            dispatcher.ErrorHandlers.Add(handler);
        }
    }
}

ServiceHost host = new ServiceHost(new Service.MyService());
host.Faulted += new EventHandler(host_faulted);
host.Description.Behaviors.Add(new ErrorServiceBehavior());
host.Open();

积分http://www.haveyougotwoods.ca/2009/06/24/creating-a-global-error-handler-in-wcf

关于2)...

诀窍是你应该使用"使用",并且应该总是在抛出异常的代理上调用Abort().文章WCF Gotcha解释了这一切.

我们使用受包含服务调用的文章启发的服务类.这是我项目的示例代码:

ServiceHelper.Use(
    proxy => seasonCodeBindingSource.DataSource = proxy.GetSeasonCodes(brandID);
);

这是ServiceHelper的代码,稍微修改一下.到目前为止,它对我们非常好.

using System;
using System.ServiceModel;

namespace Sportina.EnterpriseSystem.Client.Framework.Helpers
{
    public delegate void UseServiceDelegate(TServiceProxy proxy);

    public static class ServiceHelper where TServiceClient : ClientBase, new() where TServiceInterface : class
    {
        public static void Use(UseServiceDelegate codeBlock)
        {
            TServiceClient proxy = null;
            bool success = false;
            try
            {
                proxy = new TServiceClient();               
                codeBlock(proxy);
                proxy.Close();
                success = true;
            }
            catch (Exception ex)
            {
                Common.Logger.Log.Fatal("Service error: " + ex);                                
                throw;
            }
            finally
            {
                if (!success && proxy != null)
                    proxy.Abort();
            }
        }
    }
}

我有一个问题,在ReceiveTimeout异常之后,Channel仍然处于故障状态.这将导致任何后续连接使服务无法使用.

从我的故障状态恢复服务的修复是处理通信通道的Faulted事件:

 channelFactory = new ChannelFactory(endpoint);
 channelFactory.Faulted += OnChannelFaulted;
 var channel = channelFactory.CreateChannel();

然后定义OnChannelFaulted:

 void OnChannelFaulted(object sender, EventArgs e)
 {
     channelFactory.Abort();
 }

注意:我通过代码运行WCF配置,而不是使用Web.config中的绑定.