I'm using memcached (1.2.6) combined with a .NET session provider (http://www.codeplex.com/memcachedproviders/Release/ ProjectReleases.aspx?ReleaseId=10468) to store sessions on my site. I currently have the database backup feature turned off, so the sessions exist only in memcached.
Sessions are used on my site to hold login credentials across load- balanced servers. In times of peak traffic, there's obviously a lot of sessions being created constantly (~1% for logged-in users, 99% anonymous) so I'm trying to cut down on database traffic by getting those completely out of the database. From the docs, it looks like when memcached fills up, it starts dumping key-values based on usage, with high-use items having a higher chance of staying in memory longer. Given that that's the case, can I be reasonably sure that the 1% of my sessions/cache that are being used by active users (POSTing back often) will last in memcached if it reaches capacity? More generally, is it "safe" for me to keep those sessions in memcached only? I don't want my users to start getting logged out constantly because the site is getting hammered. Does anyone else do this? How has it worked out? Thanks for everyone's help so far in this group! --Jonathan
