XPO Team Blog
06 December 2006

And another “leftover” XPO sample – this time tunnelling through Windows Communication Foundation (WCF). Nothing much to say about this really… if you’re reading this as a single post, you might wonder what the “tunnelling of IDataStore” is all about, so let me point you to this article here for the explanation.

The download of the sample is here.

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Rich Logwood
Thanks for this great example. I have a question on your choice of singleton for the service.

In the DataStoreServerProxy class you specified the attribute [ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]

As I currently understand WCF, multiple clients accessing a singleton service may only do so one at a time. This would cause a bottleneck when multiple users require use of the service simultaneously.

Would you mind providing insights on the following questions:

1. How should one quantify the server side overhead when setting up a remote XPO service?

2. What guidelines would you follow implementing a WCF XPO service when choosing between InstanceContextModes of Session, PerCall and Single?

For example, I’ve read using InstanceContextMode.PerCall is a good idea for services that need to scale dramatically so that server side resources can be disposed of promptly even though this may be slower for individual clients needing to execute multiple calls. Are there any special considerations when implementing an XPO service as PerCall?

Thanks for all your XPO articles :)
30 December 2006
eXpress App Framework Team

This is post no. 10 in the mini series "10 exciting things to know about XAF". You can find

31 May 2008

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