I'm setting up an AppFabric caching cluster on a small webfarm (5 web servers).
The caching cluster is installed on the same servers that run the IIS, if that matters.
I only use the AppFabric cache for my Model layer, meaning mostly business logic objects created from database queries. No page caching or similar.
This works just fine when enabled on the main website.
However on one of the 5 web servers there's a second IIS site, which hosts a couple of services, amongst others 3 WCF endpoints, as well as 2 old-school ASMX webservices.
When I enabled the AppFabric caching for this site, it tears the whole cluster down. A call to Get-CacheClusterHealth shows all 5 are completely gone (100% in Unallocated named cache fractions)
The Model code is actually the exact same DLLs as we use for the main website, so I doubt it's anything in the code (since the main site works)
I noticed this error in IIS -> AppFabric Dashboard: Error occurs while parsing service file myendpoint.svc
So that got me thinking: Could this be caused by the WCF endpoints somehow ?
There is a related question to this here:- AppFabric Cache server and web application on same physical machine
Microsoft don't recommend having cache nodes being dual use (also hosting applictions). This could be the cause of your problem. We use an appfabric cache cluster but we dedicate them to appfabric and nothing else. See the article from MS here:- AppFabric Caching Physical Architecture