WCF ContractFilter Mismatch when enabling Reliable Session

Question

I have a WCF service hosted in a Windows Service. I then have a GUI(client) that then communicates to this service. It has recently been reported that communication with the service stops after being idle for 10 minutes.

I have done a bit of research and it looks like the service is discarding the connection due to inactivity. Therefore I want to increase the receive timeout and enable reliable sessions and set an inactivityTimeout to be longer. However when I do this in both the WCF service and clients app.config file I get the following error:

Setting reliableSession enabled="False" causes the client and service to run. ( although only for 10 minutes )

Doing some research the suggestion is this is because of one of the following three reasons:

• You have different contracts between client and sender.
• You're using a different binding between client and sender.
• The message security settings are not consistent between client and sender.

However as far as I can tell the settings / contracts between the client and server are consistent. I'm hoping it's something stupid. Here are my app.config for service and client:

Service

<?xml version="1.0" encoding="utf-8" ?>
<configuration>

  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
  </startup>

  <appSettings>
    <add key="aspnet:UseTaskFriendlySynchronizationContext" value="true" />
  </appSettings>

  <system.web>
    <compilation debug="true" />
  </system.web>
  <!-- When deploying the service library project, the content of the config file must be added to the host's 
  app.config file. System.Configuration does not support config files for libraries. -->
  <system.serviceModel>
    <bindings>
      <netTcpBinding>
        <binding name="NetTcpBinding_IHwResourceManagerWcfService" receiveTimeout="infinite" >
          <reliableSession enabled="True" inactivityTimeout="infinite"/>
        </binding>
      </netTcpBinding>
    </bindings>
    <client>
      <endpoint address="net.tcp://localhost:8523/HwResourceManagerWcfService"
        binding="netTcpBinding" bindingConfiguration="NetTcpBinding_IHwResourceManagerWcfService"
        contract="WindowsServices.IHwResourceManagerWcfService" name="NetTcpBinding_IHwResourceManagerWcfService">
        <identity>
          <dns value="localhost" />
        </identity>
      </endpoint>
    </client>
    <services>
      <service name="MT.Tools.HwResourceManager.WCF.HwResourceManagerWcfService">
        <endpoint address="" binding="netTcpBinding" bindingConfiguration=""
          contract="MT.Tools.HwResourceManager.WCF.IHwResourceManagerWcfService">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint address="mex" binding="mexTcpBinding" bindingConfiguration=""
          contract="IMetadataExchange" />
        <host>
          <baseAddresses>
            <add baseAddress="net.tcp://localhost:8523/HwResourceManagerWcfService" />
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="">
          <serviceMetadata httpGetEnabled="false" httpsGetEnabled="false" />
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>

</configuration>

Client

<?xml version="1.0" encoding="utf-8" ?>
<configuration>

    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>

  <system.serviceModel>
    <bindings>
      <netTcpBinding>
        <binding name="NetTcpBinding_IHwResourceManagerWcfService" receiveTimeout="infinite" >
          <reliableSession enabled="True" inactivityTimeout="infinite"/>
        </binding>
      </netTcpBinding>
    </bindings>
    <client>
      <endpoint address="net.tcp://localhost:8523/HwResourceManagerWcfService"
        binding="netTcpBinding" bindingConfiguration="NetTcpBinding_IHwResourceManagerWcfService"
        contract="WindowsServices.IHwResourceManagerWcfService" name="NetTcpBinding_IHwResourceManagerWcfService">
        <identity>
          <dns value="localhost" />
        </identity>
      </endpoint>
    </client>
    <behaviors>
      <serviceBehaviors>
        <behavior name="">
          <serviceMetadata httpGetEnabled="false" httpsGetEnabled="false" />
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
    </behaviors>

  </system.serviceModel>

</configuration>

Any help would be greatly appreciated.

Answer 1

After some more reading on this I found both the reason for the error I was seeing and a solution to the connection timeout issue.

The Error - The error was because I had different binding configurations set. By setting to an empty string for both the client and service the error was removed.

The timeout issue - Even with reliable connections enabled and a long timeout for both the inactivity and receive timeouts the 10 minute connection issue remained. I then read a post that suggested that doing a long timeout was the wrong thing to do. Instead it recommended handling the faulted exception and trying to-reconnect.