Hi all,

We are about to embark on a project and we are starting development using NHibernate 1.2. It is an ASP.NET application that is split across two or more web servers in a web farm.

In the past we have used NHibernate's second level caching capabilities but I have my doubts whether this will work in a web farm scenario. We can use sticky sessions a.k.a. sticky i.p.s.

I just want to double check people's experience with this.

Cheers

Paul

sticky sessions arent going to help with a second level cache. If one of your web servers updates an object that is in the second level cache, the other servers in the web farm wont be updated. So one server will have the latest data and all the other servers will have stale data. This could go on and on and eventually all your web servers will be out of sync with the database. The SysCache provider will be fine for read-only data but you cant use it in a web farm scenario for 2nd level cache items that are updatable.

Have a look at NHibernate.Caches.MemCache.MemCacheProvider. This is a new cache provider that works in a server environment. I personally haven't used this so I can't comment on how well it works. I'd be interested to hear some feedback about performance. Sounds great though.

I will certainly try this approach.

I will keep everyone posted on my findings.

Has anoyne else any experience with this type of caching?

Cheers

Any update on memcache?

Theres also NCache from Alachisoft. They provide a pretty slick caching system for web farms and have an NHibernate provider. I havent tried it but I got a demo and it looked great. The only problem is that it is expensive. I believe I was quoted around 1500 a processor. They require you to license your QA and staging servers as well as get dev licenses. Bummer, but if you got the dough its worth a look.