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Can several WCF services share a common BaseAddress?

Answer 1

+2 A:

Services can share BaseAddress values (including port #'s, if the Net.Tcp Port Sharing Service is running). It's the endpoint addresses that must be unique. Notice in your config file that the MEX endpoints for each ServiceHost have an address of "mex". Your other endpoints have an address of empty string. When you provide a relative address for an endpoint to WCF (in the config file at least), the base address is prepended to it. Therefore, the MEX endpoint address for the LogReader service is "net.tcp://localhost:8731/Design_Time_Addresses/SamAlyza/LogReader/mex".

Since a relative address was not set on the main service endpoint, the base address of the ServiceHost is used as the actual address for the main service endpoint. Because no two endpoints can have overlapping Uri.AbsolutePath values, your example would lead you to believe that base address values cannot be shared. The ServiceHost class that hosts WCF services does not have a built-in endpoint, whereas the ServiceEndpoint class has a ListenUri property that will be populated based on the settings you provide.

If you change the baseAddress values in your example to all match, as long as you set unique relative address values on the Endpoint elements, everything should work. However, it appears that you may run into some challenges with the MEX endpoints, since they all have the address "mex" currently. Make those unique and you should be fine.

Now, I must ask, are you sure that you are not simply wanting these services to share a namespace, rather than base addresses?

EnocNRoll 2009-01-12 19:07:45

Another point would be that a baseAddress is nothing more than the current location, so to speak. The idea is that all endpoints are generally relative to the baseAddress. Therefore, if you are trying to share the same baseAddress across all services, you are limiting your deployment options.

EnocNRoll 2009-01-12 20:40:16

If you are looking for a way to make configuration easier, you will have to switch to using code instead of configuration wiring. You could programmatically create the ServiceHost and the ServiceEndpoint instances and perhaps pull Uri.AbsolutPath values from a database.

EnocNRoll 2009-01-12 20:43:02

Yes, I am looking for a way to make the config file easier to change.So if you have any ideas about this, I'd be all ears.

Sam 2009-01-13 08:43:48

Ask another question regarding code-based WCF service instantiation, and I'll post an example static class.

EnocNRoll 2009-01-13 17:40:15

I will post a question to this effect and then post my solution.

EnocNRoll 2009-01-13 18:19:11

Answer 2

+2 A:

You can combine all contracts in one class, so you have one service with a baseaddress and one (or more) endpoint(s) per contract.

To avoid having one large class-file you can use the partial-keyword (asuming you use c#) to split the class across multiple files. Each file can implement one contract, that makes maintaining the individual interfaces much easier.

In C++ you can use #includes or multiple inheritance, but that imply a large amount of discipline...

Your config would look like this:

<services>
  <service behaviorConfiguration="WcfService.AlyzaServiceBehavior"
    name="Sam.Alyza.WcfService.ServiceAll">
    <endpoint address="Websites/" binding="netTcpBinding" contract="Sam.Alyza.WcfInterface.IServiceWebsites">
      <identity>
        <dns value="localhost" />
      </identity>
    </endpoint>
    <endpoint address="LogReader/" binding="netTcpBinding" contract="Sam.Alyza.WcfInterface.IServiceLogReader">
      <identity>
        <dns value="localhost" />
      </identity>
    </endpoint>
    <endpoint address="Systemverwaltung/" binding="netTcpBinding" contract="Sam.Alyza.WcfInterface.IServiceSystemverwaltung">
      <identity>
        <dns value="localhost" />
      </identity>
    </endpoint>
    <endpoint address="mex" binding="mexTcpBinding" contract="IMetadataExchange" />
    <host>
      <baseAddresses>
        <add baseAddress="net.tcp://localhost:8731/Design_Time_Addresses/SamAlyza/" />
      </baseAddresses>
    </host>
  </service>
</services>

Lars 2009-01-13 09:15:55

Nice idea! Only problem is: the partial ServiceAll class will be big, with lots and lots of methods.

Sam 2009-01-13 11:36:10

That's right. At the moment I see no other solution than to switch to code-based instantiation.

Lars 2009-01-13 14:22:21

Answer 3

A:

You can also set the base addresses in code if you use a custom ServiceHostFactory.

In config you can have some app setting:

<configuration>
  <appSettings>
    <add key="BaseAddress" value="http://localhost:1234" />
  </appSettings>
<configuration>

Then make a custom ServiceHostFactory:

public sealed class MyServiceHostFactory : ServiceHostFactory
{
    protected override ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses)
    {
        var baseAddy = ConfigurationManager.AppSettings["BaseAddress"];
        baseAddresses.Add(new Uri(baseAddy));
        return new ServiceHost(serviceType, baseAddresses);
    }

}

Then you also have to change your .svc files to use that factory:

<%@ ServiceHost Language="C#" Debug="true" Service="MyApp.MyService" CodeBehind="MyService.svc.cs" Factory="MyApp.MyServiceHostFactory" %>

rally25rs 2009-12-07 16:28:40

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Can several WCF services share a common BaseAddress?

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