WCF ERROR:服务器没有提供有意义的回复； [英] WCF ERROR: The server did not provide a meaningful reply;

问题描述

请有人帮我找出发生了什么.我的 WCF 服务运行良好，现在突然出现此错误:

<块引用>

服务器没有提供有意义的回复；这可能是由于合同不匹配、过早的会话关闭或内部服务器错误

我必须说，当我选择数千条记录时它仍然有效，但是当数据很大时，我收到此错误，尽管在它工作正常之前！

 private static string ConnString = "Server=127.0.0.1; Port=5432; Database=DBname; User Id=UName; Password=MyPassword;"数据表 myDT = 新数据表()；NpgsqlConnection myAccessConn = new NpgsqlConnection(ConnString);myAccessConn.Open();字符串查询 = "SELECT * FROM Twitter";NpgsqlDataAdapter myDataAdapter = new NpgsqlDataAdapter(query, myAccessConn);myDataAdapter.Fill(myDT);foreach(myDT.Rows 中的 DataRow dr){**当我有太多记录时，它会停在这里**...

web.config

<预><代码><配置><system.web><编译调试="false" targetFramework="4.0"/><httpRuntime maxRequestLength="2147483647" executionTimeout="100000"/></system.web><系统诊断><trace autoflush="true"/><来源><源名称="System.ServiceModel"switchValue="信息，活动跟踪"传播活动=真"><听众><add name="traceListener" type="System.Diagnostics.XmlWriterTraceListener" initializeData="Traces4.svclog"/></听众></来源></来源></system.diagnostics><system.serviceModel><绑定><基本HttpBinding><绑定名称="BasicHttpBinding_IDBService" closeTimeout="00:30:00"openTimeout="00:30:00" receiveTimeout="00:30:00" sendTimeout="00:30:00"allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"maxBufferSize="2147483647" maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647"messageEncoding="Text" textEncoding="utf-8" transferMode="Streamed"useDefaultWebProxy="true"><readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647"maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647"/><安全模式=无"><transport clientCredentialType="None" proxyCredentialType="None"领域=""/><message clientCredentialType="UserName" algorithmSuite="默认"/></安全></binding></basicHttpBinding></绑定><客户><端点地址="" binding="basicHttpBinding"bindingConfiguration="BasicHttpBinding_IDBService" contract="DBServiceReference.IDBService"name="BasicHttpBinding_IDBService"/></客户端><行为><服务行为><行为名称=""><serviceMetadata httpGetEnabled="true"/><serviceDebug includeExceptionDetailInFaults="true"/><dataContractSerializer maxItemsInObjectGraph="2147483646"/></行为></serviceBehaviors></行为><serviceHostingEnvironment aspNetCompatibilityEnabled="false" multipleSiteBindingsEnabled="true"/></system.serviceModel></配置>

客户端配置(已修改)

<预><代码><配置><system.serviceModel><绑定><基本HttpBinding><绑定名称="BasicHttpBinding_IRouteService" maxBufferSize="2147483647"maxReceivedMessageSize="2147483647"><安全模式=无"/></binding><绑定名称="BasicHttpBinding_IDBService" closeTimeout="00:30:00"openTimeout="00:30:00" receiveTimeout="00:30:00" sendTimeout="00:30:00"maxBufferSize="2147483647" maxReceivedMessageSize="2147483647"transferMode="缓冲" ><安全模式=无"/></binding></basicHttpBinding><自定义绑定><绑定名称="CustomBinding_IRouteService"><binaryMessageEncoding/><httpTransport maxReceivedMessageSize="2147483647"maxBufferSize="2147483647"/></binding></customBinding></绑定><客户><端点地址="http://dev.virtualearth.net/webservices/v1/routeservice/routeservice.svc"binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IRouteService"contract="BingRoutingService.IRouteService" name="BasicHttpBinding_IRouteService"/><端点地址="http://dev.virtualearth.net/webservices/v1/routeservice/routeservice.svc/binaryHttp"binding="customBinding" bindingConfiguration="CustomBinding_IRouteService"contract="BingRoutingService.IRouteService" name="CustomBinding_IRouteService"/><端点地址="" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IDBService"contract="DBServiceReference.IDBService" name="BasicHttpBinding_IDBService"/></客户端></system.serviceModel></配置>

在我的文件 scvlog 中，我没有发现任何异常！我不知道我还能做些什么来了解问题出在哪里.请有人帮助我！！！

解决方案

一个不同的答案，以防万一有人到达这里，因为我正在寻找问题的一般答案.

似乎执行驴工作的 DataContractSerializer 非常挑剔，但并不总是将真正的错误传递给客户端.服务器进程在失败后立即终止 - 因此找不到错误.在我的例子中，问题是一个用作标志的枚举，但没有用 [Flags] 属性装饰(挑剔或什么！).

为了解决这个问题，我创建了一个序列化程序的实例并检查了调试器中的错误；这是一个代码片段，因为我手头有它.

响应评论中的请求......

修改了代码片段以显示我现在使用的辅助方法.与以前大致相同，但使用了方便的通用包装器.

public static T CheckCanSerialize(this T returnValue) {var lDCS = new System.Runtime.Serialization.DataContractSerializer(typeof(T));字节[] lBytes;使用 (var lMem1 = new IO.MemoryStream()) {lDCS.WriteObject(lMem1, returnValue);lBytes = lMem1.ToArray();}TlResult;使用 (var lMem2 = new IO.MemoryStream(lBytes)) {lResult = (T)lDCS.ReadObject(lMem2);}返回 lResult;}

而要使用这个，不是返回一个对象，而是在调用辅助方法后返回该对象，所以

public MyDodgyObject MyService() {......做很多工作......返回我的结果；}

变成

public MyDodgyObject MyService() {......做很多工作......返回 CheckCanSerialize(myResult);}

序列化中的任何错误都会在服务停止关注之前抛出，因此可以在调试器中进行分析.

注意；我不建议将调用留在生产代码中，它具有序列化和反序列化对象的开销，一旦代码被调试就没有任何实际好处.

希望这对某人有所帮助 - 我浪费了大约 3 个小时试图追踪它.

please somebody can help me to find out what is happened. I have my WCF service which worked fine, and now suddenly I have this error:

The server did not provide a meaningful reply; this might be caused by a contract mismatch, a premature session shutdown or an internal server error

I must tell that it still works when I select some thousands of records, but when the data is huge I receive this error, although before it worked fine!

    private static string ConnString = "Server=127.0.0.1; Port=5432; Database=DBname; User Id=UName; Password=MyPassword;"
    DataTable myDT = new DataTable();

                NpgsqlConnection myAccessConn = new NpgsqlConnection(ConnString);
                myAccessConn.Open();
        string query = "SELECT * FROM Twitter";

                NpgsqlDataAdapter myDataAdapter = new NpgsqlDataAdapter(query, myAccessConn);

                myDataAdapter.Fill(myDT);
                foreach (DataRow dr in myDT.Rows)
                {
   **WHEN I HAVE TOO MANY RECORDS IT STOPS HERE**
        ...

web.config

<configuration>
    <system.web>
        <compilation debug="false" targetFramework="4.0" />
      <httpRuntime maxRequestLength="2147483647" executionTimeout="100000" />
    </system.web>
  <system.diagnostics>
    <trace autoflush="true" />
    <sources>
      <source name="System.ServiceModel"
              switchValue="Information, ActivityTracing"
              propagateActivity="true">
        <listeners>
          <add name="traceListener" type="System.Diagnostics.XmlWriterTraceListener" initializeData="Traces4.svclog"/>
        </listeners>
      </source>
    </sources>
  </system.diagnostics>
  <system.serviceModel>
        <bindings>
            <basicHttpBinding>
                <binding name="BasicHttpBinding_IDBService" closeTimeout="00:30:00"
                    openTimeout="00:30:00" receiveTimeout="00:30:00" sendTimeout="00:30:00"
                    allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
                    maxBufferSize="2147483647" maxBufferPoolSize="2147483647" maxReceivedMessageSize="2147483647"
                    messageEncoding="Text" textEncoding="utf-8" transferMode="Streamed"
                    useDefaultWebProxy="true">
                    <readerQuotas maxDepth="2147483647" maxStringContentLength="2147483647" maxArrayLength="2147483647"
                        maxBytesPerRead="2147483647" maxNameTableCharCount="2147483647" />
                    <security mode="None">
                        <transport clientCredentialType="None" proxyCredentialType="None"
                            realm="" />
                        <message clientCredentialType="UserName" algorithmSuite="Default" />
                    </security>
                </binding>
            </basicHttpBinding>
        </bindings>
    <client>
      <endpoint address="" binding="basicHttpBinding" 
          bindingConfiguration="BasicHttpBinding_IDBService" contract="DBServiceReference.IDBService"
          name="BasicHttpBinding_IDBService" />
    </client>
        <behaviors>
            <serviceBehaviors>
                <behavior name="">
                  <serviceMetadata httpGetEnabled="true" />
                  <serviceDebug includeExceptionDetailInFaults="true" />
                  <dataContractSerializer maxItemsInObjectGraph="2147483646" />
                </behavior>
            </serviceBehaviors>
        </behaviors>
        <serviceHostingEnvironment aspNetCompatibilityEnabled="false" multipleSiteBindingsEnabled="true" />
    </system.serviceModel>
</configuration>

client config (Edited)

<configuration>
        <system.serviceModel>
            <bindings>
                <basicHttpBinding>
                    <binding name="BasicHttpBinding_IRouteService" maxBufferSize="2147483647"
                        maxReceivedMessageSize="2147483647">
                        <security mode="None" />
                    </binding>
                    <binding name="BasicHttpBinding_IDBService" closeTimeout="00:30:00"
                        openTimeout="00:30:00" receiveTimeout="00:30:00" sendTimeout="00:30:00"
                        maxBufferSize="2147483647" maxReceivedMessageSize="2147483647"
                        transferMode="Buffered" >

                        <security mode="None" />
                    </binding>
                </basicHttpBinding>
                <customBinding>
                    <binding name="CustomBinding_IRouteService">
                        <binaryMessageEncoding />
                        <httpTransport maxReceivedMessageSize="2147483647"
                            maxBufferSize="2147483647" />
                    </binding>
                </customBinding>
            </bindings>

            <client>
                <endpoint address="http://dev.virtualearth.net/webservices/v1/routeservice/routeservice.svc"
                    binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IRouteService"
                    contract="BingRoutingService.IRouteService" name="BasicHttpBinding_IRouteService" />
                <endpoint address="http://dev.virtualearth.net/webservices/v1/routeservice/routeservice.svc/binaryHttp"
                    binding="customBinding" bindingConfiguration="CustomBinding_IRouteService"
                    contract="BingRoutingService.IRouteService" name="CustomBinding_IRouteService" />
                <endpoint address="" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IDBService"
                    contract="DBServiceReference.IDBService" name="BasicHttpBinding_IDBService" />
            </client>
        </system.serviceModel>
    </configuration>

In my file scvlog I don' t get any exception! I don't have any other idea what else I can do for understand where is the problem. Please somebody help me!!!

解决方案

A different answer, just in case anyone arrives here as I did looking for a general answer to the question.

It seems that the DataContractSerializer that does the donkey-work is incredibly finicky, but doesn't always pass the real error to the client. The server process dies straight after the failure - hence no error can be found. In my case the problem was an enum that was used as flags, but not decorated with the [Flags] attribute (picky or what!).

To solve it I created an instance of the serializer and inspected the error in the debugger; here's a code snippet since I have it to hand.

EDIT: In response to request in comments ...

Amended the code snippet to show the helper method I now use. Much the same as before, but in a handy generic wrapper.

public static T CheckCanSerialize<T>(this T returnValue) {
    var lDCS = new System.Runtime.Serialization.DataContractSerializer(typeof(T));

    Byte[] lBytes;
    using (var lMem1 = new IO.MemoryStream()) {
        lDCS.WriteObject(lMem1, returnValue);
        lBytes = lMem1.ToArray();
    }

    T lResult;
    using (var lMem2 = new IO.MemoryStream(lBytes)) {
        lResult = (T)lDCS.ReadObject(lMem2);
    }

    return lResult;
}

And to use this, instead of returning an object, return the object after calling the helper method, so

public MyDodgyObject MyService() {
    ... do lots of work ...
    return myResult;
}

becomes

public MyDodgyObject MyService() {
    ... do lots of work ...
    return CheckCanSerialize(myResult);
}

Any errors in serialization are then thrown before the service stops paying attention, and so can be analysed in the debugger.

Note; I wouldn't recommend leaving the call in production code, it has the overhead of serializing and deserializing the object, without any real benefit once the code is debugged.

Hope this helps someone - I've wasted about 3 hours trying to track it down.

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