Our situation: we have a busy ASP.NET site and use the user profile intensively. This means that not only do we read the profile on every request, but we also write (at least something) in it on most requests. Users typically spend like 15 minutes on our site. We use memcached as a caching system and are very happy with that.
Now, I was thinking that we could offload a lot of select and update queries from the profile DB if we would have memcached act as a cache front.
Anyone has production and large-scale experience with this setup? Any good tricks for only updating every now and then during a session, but never loosing the last change?