WCF 4 Routing Multicast Configuration Frustration - wcf

Question

I have been using stackoverflow.com as a resource as a professional programmer for years now. I would say 8 out of 10 times when I search for something on google, I get pointed to a question and answer here, and I am always relieved when that happens, because I know I am about to find the information I need.
I have been pulling my hair out trying to figure (what I think to be) a simple problem out, concerning setting up a routing service using WCF technology. I have browsed through the questions with similar titles here, and I have consulted a great many resources (both actual books on the subject, as well as websites) trying to figure this out, to no avail.
In a nutshell, I want to setup a system with the following layout:
{client}<-basicHTTP->{portal/router}<-fullWCF-WS*->{end-point-services1..n}
client: gets service reference to portal, able to call functions at end-point service
portal/router: gets requests from client, and sends them on to end-point services in a multi-cast setup
end-point-services1..n: gets request from client, routed through portal, processes request to search for things, and either responds, or logs data in a database to be checked later
I am, 100%, able to get a routing service up and running. The most successful models I have been able to follow, were outlined in the "What's new in WCF4: exercises 8 & 9, content bridging & routing" (msdn.microsoft.com/en-us/gg465212) and "Hello World with the Routing Service" (msdn.microsoft.com/en-us/library/dd795218.aspx) But I have used bits and pieces from all of the sources I have consulted (listed below).
Basically, what is frustrating me, is that I want a client (a 3rd party) to be able to just add a web service reference to the portal service (or, worst case scenario, use the svcutil.exe method), and be done with setup on their part. With that reference, they will have references to all the functions/methods they would want to call in all scenarios. The models I have looked at that do this require 2 references, one to the actual service, and one to the router, and then force the client to specifically call the router in their setup. None of my other attempts to make this particular setup work, have worked.
Your help with this would be greatly appreciated.
Here is a simplified version of my working model that almost is doing what I want:
(note, all services are being hosted in IIS)
PORTAL SERVICE (and IIS Host)
Portal.svc:
<%# ServiceHost Service="System.ServiceModel.Routing.RoutingService, System.ServiceModel.Routing, version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
Web.config:
<configuration>
<system.serviceModel>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
<bindings>
...
</bindings>
<client>
<endpoint address="http://searcher1/Searcher.svc/general" binding="basicHttpBinding" contract="*" name="regularSearchServiceEndpoint" />
<endpoint address="http://searcher2/Searcher.svc/general" binding="basicHttpBinding" contract="*" name="regularSearchServiceEndpoint2" />
</client>
<behaviors>
...
</behaviors>
<routing>
<filters>
<filter name="MatchAllFilter" filterType="MatchAll" />
</filters>
<filterTables>
<filterTable name="filterTable1">
<add filterName="MatchAllFilter" endpointName="regularSearchServiceEndpoint" backupList="backupList1" priority="0"/>
</filterTable>
</filterTables>
<backupLists>
<backupList name="backupList1">
<add endpointName="regularSearchServiceEndpoint2"/>
</backupList>
</backupLists>
</routing>
<services>
<service behaviorConfiguration="routingConfiguration" name="System.ServiceModel.Routing.RoutingService">
<endpoint address="general" binding="basicHttpBinding" name="routerEndpoint1" contract="System.ServiceModel.Routing.IRequestReplyRouter" />
</service>
</services>
</system.serviceModel>
</configuration>
SEARCH SERVICE
ISearch.cs:
namespace SearchService
{
[ServiceContract]
public interface ISearch
{
[OperationContract]
string Ping();
[OperationContract]
string searchByInput(string input);
}
}
App.config:
<configuration>
<!-- 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>
<basicHttpBinding>
...
</basicHttpBinding>
<customBinding>
...
</customBinding>
</bindings>
<client>
...
</client>
<services>
<service name="SearchService.Search">
<endpoint address="general" binding="basicHttpBinding" contract="SearchService.ISearch" name="SearchService">
<identity>
<dns value="localhost" />
</identity>
</endpoint>
<endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange"/>
<host>
<baseAddresses>
<add baseAddress="http://localhost:8732/Design_Time_Addresses/SearchService/Service1/"/>
</baseAddresses>
</host>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior>
<serviceMetadata httpGetEnabled="True"/>
<serviceDebug includeExceptionDetailInFaults="False"/>
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>
</configuration>
SEARCH SERVICE HOST
Search.svc:
<%# ServiceHost Service="SearchService.Search" %>
Web.config:
<configuration>
<system.serviceModel>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
<bindings>
<basicHttpBinding>
<!--copied over from SearchService.App.config-->
</basicHttpBinding>
<customBinding>
<!--copied over from SearchService.App.config-->
</customBinding>
</bindings>
<client>
<!--copied over from SearchService.App.config-->
</client>
<services>
...
</services>
<behaviors>
...
</behaviors>
</system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
</configuration>
CLIENT (where it all goes wrong)
Only way I have been able to get it to do what I want, is to add a web service reference to the searcher service (named "remotehost"), and then manually add client endpoints to the app.config file for the router, and force the client code to use that, INSTEAD of the direct link it already has to the searcher
Main.cs:
namespace Client
{
public partial class Main : Form
{
remotehost.SearchClient proxy;
public Main()
{
InitializeComponent();
proxy = new remotehost.SearchClient("RouterService");//("BasicHttpBinding_ISearch")
}
private void button1_Click(object sender,EventArgs e)
{
string response = string.Empty;
//uses method exposed by the SearchService service
response = proxy.Ping();
MessageBox.Show("Response from remote service:\n" + response
"Ping Response",
MessageBoxButtons.OK,
MessageBoxIcon.Information);
}
}
}
App.config:
<configuration>
<system.serviceModel>
<bindings>
<basicHttpBinding>
...
</basicHttpBinding>
</bindings>
<client>
<endpoint address="http://searcher1/Searcher.svc/general" binding="basicHttpBinding" bindingConfiguration="SearchService" contract="remotehost.ISearch" name="SearchService" />
<!--I manually added this-->
<endpoint address="http://portal/Portal.svc/general" binding="basicHttpBinding" contract="remotehost.ISearch" name="RouterService" />
</client>
</system.serviceModel>
</configuration>
I want to emphasize, this all WORKS, but it doesn't work the WAY I want it to. I am fairly certain I can push/pull/cajole this into the elegant setup I am envisioning, but I can't seem to find a resource or guide that will walk me through it for the first time.
Help?
Sources I have consulted, before coming here:
Learning WCF: A Hands-on Guide, by Bustamante, Michele Leroux {978-0-5961-0162-6} (read cover to cover, and did all exercises)
Windows Communication Foundation 4: Step By Step {978-0-7356-4556-1} (focused on chapter 14: Discovering Services and Routing Messages)
msdn.microsoft.com/en-us/library/ms734712.aspx {WCF: Getting Started Tutorial}
msdn.microsoft.com/en-us/gg465212 {what's new in WCF4: exercises 8 & 9, content bridging & routing}
codeproject.com/Articles/146835/How-to-create-scalable-services-with-WCF-4-0-Route {How to create scalable services with WCF 4.0 Router and Discovery services}
msdn.microsoft.com/en-us/library/dd795218.aspx {Hello World with the Routing Service}
msdn.microsoft.com/en-us/library/ee517421.aspx {routing}
msdn.microsoft.com/en-us/library/ee517423.aspx {routing service overview}
msdn.microsoft.com/en-us/library/ee517418.aspx {routine service features}
msdn.microsoft.com/en-us/library/ee517422.aspx {routing intro}
msdn.microsoft.com/en-us/library/ee517420.aspx {routing contracts}
msdn.microsoft.com/en-us/library/bb332338.aspx {wcf routing}
msdn.microsoft.com/en-us/library/ms730158.aspx {more wcf routing}
msdn.microsoft.com/en-us/library/ee354381.aspx {more wcf routing}
dandcohen.wordpress.com/2010/03/02/wcf-4-routing-service-multicast-sample/ {WCF 4 Routing Service Multicast sample}
UPDATE: 2012-04-28:
I figured out a way to do what I wanted. It still isn't as elegant as I wanted, but it get the job done and has allowed me to move forward.
Basically, take the interface from the main service, and implement it in a new service, call it router or portal, or whatever. In the new router/portal service, add a new service reference to the main service.
Now, both services are using the same interface, and have the same signatures for all their methods, so you can then just give the portal/router service wsdl to the 3rd party client, and only allow your portal/router service to communicate with the main service.
Additionally, if you have more than one main service, you can use the portal/router service to decide which of the main services to send requests to, using multiple service references to them, and proxies to send the jobs onward. It works really well.
It is basically a manual front-end routing service, but the beauty is, the detailed work can be done in the main services on a threading model, while the gatekeeping work can be done at the portal/router, so only actual requests are sent to the main services, allowing them to only do work, and the portal services to decide how or if they get that work. The next step I want to add it automatic discovery of new services, but for now, manual configuration is working fine.
I can post the source code for what I came up with, if anyone wants to see it and requests it.

Answer 1

The fundamental problem is that the router knows nothing about the service contract that the service is using - it uses a universal contract (one which uses the Message type). Therefore, there is no way for the router to auto-generate the metadata for the client.
What you will need to do is provide the metadata yourself, maybe as a static WSDL document, with the correct addresses in it and point clients to this