What is the cause of exception in wcf peer-to-peer service with callbacks ?
- by miensol
I've been playing around with WCF peer to peer, one way operation contract and callbacks.
I have a following service:
[ServiceContract(CallbackContract = typeof(ICodeFoundCallback))]
public interface ICodeSearch
{
[OperationContract(IsOneWay = true)]
void Search(string searchQuery);
}
public interface ICodeFoundCallback
{
[OperationContract(IsOneWay = true)]
void Found(string found);
}
public class CodeSearchService : ServiceWithCallback<ICodeFoundCallback>, ICodeSearch
{
public void Search(string searchQuery)
{
Console.WriteLine("Searching for :" + searchQuery);
Callback(t=> t.Found(searchQuery));
}
}
public class ServiceWithCallback<T>
{
protected void Callback(Action<T> call)
{
var callbackChanel = OperationContext.Current.GetCallbackChannel<T>();
call(callbackChanel);
}
}
with such config on server
<system.serviceModel>
<services>
<service name="CodeSearch.Service.CodeSearchService" behaviorConfiguration="CodeSearchServiceBehavior">
<host>
<baseAddresses>
<add baseAddress="net.p2p://CodeSearchService"/>
</baseAddresses>
</host>
<endpoint
name="CodeSearchServiceEndpoint"
address=""
binding="netPeerTcpBinding"
bindingConfiguration="BindingUnsecure"
contract="CodeSearch.Service.ICodeSearch"
/>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="CodeSearchServiceBehavior">
<serviceMetadata />
</behavior>
</serviceBehaviors>
</behaviors>
<bindings>
<netPeerTcpBinding>
<binding name="BindingUnsecure">
<security mode="None"/>
<resolver mode="Pnrp"/>
</binding>
</netPeerTcpBinding>
<customBinding>
<binding name="CodeSearchServiceEndpoint">
<binaryMessageEncoding maxReadPoolSize="64" maxWritePoolSize="16"
maxSessionSize="2048">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
</binaryMessageEncoding>
<peerTransport maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
port="0">
<security mode="None" />
</peerTransport>
</binding>
</customBinding>
</bindings>
<system.serviceModel>
And simple client generated by Visual studio tooling.
When I run two or more servers, and client invokes Search method:
search method is called on each server
first server calls client callback properly
second server throws
ArgumentException "A property with the name 'TransactionFlowProperty' already exists" when invoking client callback (Found method)
I've no idea what is going on since as far as I know transaction flow is by default set to none.
Could anyone help me solve this issue ?
