Re: Session and Multi Server Architecture

Per Jessen wrote:

Stut wrote:

There's no question of locking users to particular machines, nor of uneven distribution. LVS will distribute evenly or according to weights.

Indeed, but you must see that making the decision of which server to use per request will result in a more even distribution than deciding once per session.

You might see a somewhat uneven distribution if you only have a small number of machines, but the resources you're saving by not having memcached replicate objects will now be available for that slightly less even distribution.

I'm not sure what you mean by "replicate objects".

Having said that I don't see a problem with depending on a particular piece of software as a dependency of the application. Your app already requires PHP, and most likely requires a bunch of extensions to be present so I don't see a major problem in adding memcache to that list, especially if it means you can use it much more efficiently by assuming it's available.

My personal choice would be not to have my application deal directly with caching, but that's mostly a matter of choice.

Abstraction is great but where scalability is needed it can prove to be horribly inefficient, but as you say it's a matter of choice. -Stut -- http://stut.net/