64 bit large memory cache

Peter van Dijk peter at nextgear.nl
Mon Nov 28 01:21:49 PST 2005

On Mon, Nov 28, 2005 at 01:30:40AM -0700, Denis Antipov wrote:
> The reason I've updated memcache to support over 4 Gb of RAM is because I'm
> having a session data loss, which I'm storing in memcache. The problem is
> occuring primarily with AOL ISP subscribers, who appear to be accessing the
> Internet via AOL proxy servers. This becomes a problem when their IP
> addresses change and all of the session data stored for a particular session
> on memcached to a particular Apache server disappears somewhere. This

We persist clients to backend webservers per client /24 instead of
per client IP. This catches clusters of proxies fine in practice. In
your case if I'm reading right, maybe you should change from IP+sessionID
to IP-masked-to-/24+sessionID as your memcache key.

The only users complaining about sessions getting lost nowadays
are those that use products like Google Web Accelerator.


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