Silverlight WCF client, sharepoint web services go silent

Question

I've got a silverlight app installed as a web part feature in a sharepoint site collection. Everything works fine in a small development site collection, but in a large collection with many subsites, the app has problems with Sharepoint web services. It hits the sharepoint web services and retrieves data about each subsite, but at some point along the way, the server simply stops responding. No HTTP error messages (and consequently, no exceptions bubble up the call stack), nothing at all. I've checked the server-side as well, and found nothing in the event log.

My first guess was that it might have something to do with authentication timing out, but shouldn't accessing the web services cause the authentication tickets to be renewed (both Forms and Windows auth)?

Has anyone seen behavior like this before?

Answer 1

It sounds like a timeout is the best lead you have.

I believe there is a fairly firm timeout for operations. I haven't seen this in web parts, but have seen it in custom Visual Studio workflows within SharePoint where the initial activity on a workflow performed a somewhat long running process without getting the workflow to sleep first and become asynchronous. If I recall correctly, the timeout is 2 minutes.

I just did a quick search which yielded this link which confirms that and tells you how to tweak the timeout.

In the end you need to minimize the rows and maybe the sites (SPWebs) that are being queried. If you aren't using it already, I would look at SPSiteDataQuery or SiteData.asmx to help with your query.