CAS operations and locking using CouchbaseSessionStateProvider

Hi,

We are experience 100% cpu on our web servers in some cases and we suspect that it may have something to do with couchbase/memcache session state provider.

We can see CAS hit persecaround 1.2k and some spikes up to 2-2,5k and then down to 0.5k and back to table 1.2 k.
We also have 10-20 CAS badval requests.

The question is what is CAS and can CAS affect our website in an negative way. If i understand correctly then CAS has something to do with securing the information between requests!?

I have seen something about an option “exclusiveAccess” in the configuration for the session state provider. Is this flag related to CAS?

We have 4 web frontend servers running IIS and using sessionstateprovider.

Glad for any answer that can give more information or exclude this as a problem.

Br
Johan