The Service Bus Bindings and WAS/IIS

clemensv — Wed, 05 Nov 2008 17:16:43 GMT

We’ve been getting some questions along the lines of “I am hosting a service as xyz.svc in IIS and have changed the config to use on of the Service Bus bindings, but the service never gets called?”

That’s right. It doesn’t. The reason for that is that we don’t yet have WAS/IIS integration for any of the Service Bus bindings in the November 2008 CTP. Enabling the WCF WAS activation scenario that puts the NetTcpRelayBinding and friends on par with their WCF siblings is on our work backlog for the next major milestone.

It’s worth considering for a moment what that integration requires. Fundamentally, all of the Relay bindings replace the local TCP or HTTP listener with a listener that sits up in the cloud and services then connect up to that listener to create an inbound route for received messages. That’s similar to how local services interact with WCF’s shared TCP listener or HTTP.SYS, but there are quite a few important differences. First, all Relay listeners need to acquire and present an Access Control token when they start listening on the Service Bus. In contrast, the local listener facilities are ACL’d using the local or domain account system and use the Windows process identity to decide on whether a process may or may not listen on a particular port and/or namespace. Second, since the actual listener is off-machine, we need to spin up the connection as the IIS/WAS host spins up and need to make sure that the connection is kept alive and aggressively reconnects when dropped for any reason. That’s something you don’t really have to worry much about when the listener sits right there on the same machine as your own service and the connection is a named pipe. Third, the local listeners listen on a particular host address and port; the Relay listeners listen on a leaf of a namespace tree and that namespace may be shared amongst many listeners living on a multitude of different machines in different locations. Fourth, ... well you get the picture.

Bottom line: Not having support for WAS activation and xyz.svc service endpoints is by no means an oversight. It’s on the list.

.NET Services: MSDN Developer Center

clemensv — Wed, 05 Nov 2008 13:27:31 GMT

The MSDN Developer Center for .NET Services is the first stop to go to for technical information on the Service Bus, the Access Control Service and the Workflow Service.

There quite a bit of documentation for “my” feature area, the .NET Service Bus, including description of all the bindings and most of the object model surface area. Since we had quite a bit of object model churn up until a few weeks before PDC as we’ve exploded the former, singular RelayBinding into two handful of WCF-aligned bindings, the reference documentation isn’t yet in the familiar MSDN reference format and also doesn’t yet work with Visual Studio’s “F1”. We’re obviously going to address that in the next major milestone now that the dust is settling a bit and the programming model is already quite a bit closer to what we want it to be for our “V1” release.

Clemens Vasters, Bldg 42 : .NET Services

The Service Bus Bindings and WAS/IIS

.NET Services: MSDN Developer Center