Hosting more than 25 WCF services in Azure - wcf

Question

We're running into Azure's limit of 25 internal endpoints with our WCF services. In keeping with SOA principles, our WCF services are fairly small, generally one per "noun" in our system. We are defining one Azure InternalEndpoint per service contract. We now want to add our 26th WCF service but can't because of the limit of 25 endpoints. We really don't want to arbitrarily start combining service contracts simply because of this Azure limitation.
Question: is there a better way to host lots of WCF services that doesn't require one endpoint per service contract?
Here's an example csdef file snippet:
<ServiceDefinition name="MyDeployment" xmlns="http://schemas.microsoft.com/ServiceHosting/2008/10/ServiceDefinition">
<WorkerRole name="MyWorkerRole" vmsize="Small">
<Endpoints>
<InternalEndpoint protocol="tcp" name="IUserService" />
<InternalEndpoint protocol="tcp" name="IArticleService" />
<InternalEndpoint protocol="tcp" name="IDocumentService" />
<InternalEndpoint protocol="tcp" name="ICommentingService" />
<InternalEndpoint protocol="tcp" name="ILocationService" />
<InternalEndpoint protocol="tcp" name="IAuthorizationService" />
<InternalEndpoint protocol="tcp" name="IAuthenticationService" />
<InternalEndpoint protocol="tcp" name="ILoggingService" />
<InternalEndpoint protocol="tcp" name="IService09" />
<InternalEndpoint protocol="tcp" name="IService10" />
<!-- and so on -->
<InternalEndpoint protocol="tcp" name="IService24" />
<InternalEndpoint protocol="tcp" name="IService25" />
<InternalEndpoint protocol="tcp" name="IServiceWeWantToAddButCannot" />
</Endpoints>
</ServiceDefinition>

Answer 1

As I mentioned in my comment to your question, I don't think you really need all of those InternalEndpoints that you have. You are pairing those one-to-one with your WCF Endpoints. This is probably wrong. Instead, pair them up with your WCF Bindings/Behaviors (i.e. one per port, really). In our case, we have ~250 different WCF Services all going through this one endpoint. Here is 100% of our endpoints from our csdef file:
<Endpoints>
<InputEndpoint name="WcfConnections" protocol="tcp" port="8080" localPort="8080" />
</Endpoints>
(While we use InputEndpoint instead of InternalEndpoint, there should be no difference from this question's perspective.)
That single endpoint is utilized by three different netTcpBindings in our Self-Hosted TCP service application. We also have a Web App version of our TCP services (for easy local dev hosting/testing in IIS) and the bindings we use are:
<bindings>
<netTcpBinding>
<binding name="A" maxBufferPoolSize="5242880" maxBufferSize="5242880" maxReceivedMessageSize="5242880" listenBacklog="100" maxConnections="1000">
<readerQuotas maxDepth="256" maxStringContentLength="16384" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<security mode="Transport">
<transport clientCredentialType="Certificate" />
</security>
</binding>
<binding name="B" maxBufferPoolSize="15728640" maxBufferSize="15728640" maxReceivedMessageSize="15728640" listenBacklog="100" maxConnections="1000">
<!-- 15MB max size -->
<readerQuotas maxDepth="256" maxStringContentLength="15728640" maxArrayLength="15728640" maxBytesPerRead="204800" maxNameTableCharCount="15728640" />
<security mode="Transport">
<transport clientCredentialType="Certificate" />
</security>
</binding>
<binding name="C" maxBufferPoolSize="524288" maxBufferSize="524288" maxReceivedMessageSize="524288" listenBacklog="100" maxConnections="1000">
<!-- 0.5MB max size -->
<readerQuotas maxDepth="256" maxStringContentLength="524288" maxArrayLength="524288" maxBytesPerRead="204800" maxNameTableCharCount="524288" />
<security mode="Transport">
<transport clientCredentialType="Certificate" />
</security>
</binding>
</netTcpBinding>
</bindings>
In the end, as long as you're willing to share multiple services per port (except for some very high-load situations, this should be fine with a proper self-hosting app), then what you're doing is unnecessary.
Perhaps your larger problem and the question you need to learn to ask is, "How can I host multiple services on a single port in a self-hosted WCF app?" If that's the case, check out this code (note, the endpoint object we use in the loop is simply a struct that holds a few key pieces of each WCF endpoint):
// Build up Services
var hosts = new List<ServiceHost>();
foreach (var endpoint in endpoints)
{
var host = new ServiceHost(endpoint.ServiceType, new Uri(string.Format("net.tcp://{0}:{1}", FullyQualifiedHostName, SharedTcpPortNumber)));
hosts.Add(host);
foreach (var behavior in MyBehaviorSettings)
{
if (behavior is ServiceDebugBehavior)
host.Description.Behaviors.Find<ServiceDebugBehavior>().IncludeExceptionDetailInFaults = (behavior as ServiceDebugBehavior).IncludeExceptionDetailInFaults;
else
host.Description.Behaviors.Add(behavior);
}
if (endpoint.ServiceContract == null)
throw new Exception();
if (endpoint.ServiceBinding == null)
throw new Exception();
if (endpoint.EndpointUrl == null)
throw new Exception();
if (endpoint.ListenUrl == null)
throw new Exception();
// Add the endpoint for MyService
host.AddServiceEndpoint(endpoint.ServiceContract, endpoint.ServiceBinding, endpoint.EndpointUrl, new Uri(endpoint.ListenUrl));
host.Open();
}

Answer 2

Well I would say that you pushed the SOA "principles" a bit too far, if the end result is something like 25 services. Document service?! ILoggingService?!
There are a few good services that should not really exist as individual entities, because they are something that supports your system but they are not services per se. I would say that you need to changes a few of your services, combine then something like 10 would even be a very big number.
Something like this:
Support
Logging
Document
Localization
Articles
Products
Customers
Authentication
Authorization
Something like that, with 4 services only. I think you're missing the composition aspect.

Answer 3

WCF can host several services on same physycal port.
For example if you register your services to endpoints like:
http:// 145.12.12.23:1000/
Then you will not be able to use same port.
But if you will add to the end for example contract name - you able to register services to such endpoints:
http:// 145.12.12.23:1000/AContract
http:// 145.12.12.23:1000/BContract
http:// 145.12.12.23:1000/CContract
WCF will create proxy that will map each URL to specific host.