Question

I’m developing a web service whose methods will be called from a ‘dynamic banner’ that will show a sort of queue of messages read from a sql server table.

The banner will have a heavy pressure in the home pages of high traffic sites; every time the banner will be loaded, it will call my web service, in order to obtain the new queue of messages.

Now: I don’t want that all this traffic drives queries to the database every time the banner is loaded, so I’m thinking to use the asp.net cache (i.e. HttpRuntime.Cache[cacheKey]) to limit database accesses; I will try to have a cache refresh every minute or so.

Obviously I’ll try have the messages as little as possible, to limit traffic.

But maybe there are other ways to deal with such a scenario; for example I could write the last version of the queue on the file system, and have the web service access that file; or something mixing the two approaches…

The solution is c# web service, asp.net 3.5, sql server 2000.

Any hint? Other approaches?

Thanks

Andrea

Answer 1

It depends on a lot of things:

• If there is little change in the data (think backend with ‘publish’ button or daily batches), then I would definitely use static files (updated via push from the backend). We used this solution on a couple of large sites and worked really well.
• If the data is small enough, memory caching (i.e. Http Cache) is viable, but beware of locking issues and also beware that Http Cache will not work that well under heavy memory load, because items can be expired early if the framework needs memory. I have been bitten by it before! With the above caveats, Http Cache works quite well.