WOW, this particular thread has been going around and around. The real question is, do you need memcached for storing session data or for caching data that is persisted elsewhere?
To me session data is state about the request(s) that is not stored in a DB. For instance - multi page flows, where the state from the previous page is not stored in a temp table, is commonly stored in the HTTP session or in a server side session. In this case, if the data is lost, the data is NOT able to be reconstructed, as it is not stored anywhere. Cached data is data that if lost can be easily reconstructed from elsewhere. memcached is NOT a great storage device for session data (unless it is also stored in a DB, which would then make session data cached data). Because as stable as memcached is, the data could be evicted or access to the server may be lost, because of a bad switch. So are you storing session data or cached data? On Jul 1, 3:01 pm, Syed Ali <[email protected]> wrote: > I guess memcache in this scenario is being used as a runtime db... > > I know of a few apps doing that > > On 7/1/09, Henrik Schröder <[email protected]> wrote: > > > > > Wait, what does that even mean when it comes to a LRU cache? It's a cache, > > if one of the servers in your cluster goes down, you'll get a slightly lower > > hitrate, but from some sort of systems perspective, you have 100% uptime? > > > /Henrik > > > On Wed, Jul 1, 2009 at 21:40, Josef Finsel <[email protected]> wrote: > > >> If you *really *need high availability *and* you can run Microsoft > >> products, check out Velocity. It's supposed to be a cache but it supports > >> High Availability, among other things. > > >> On Tue, Jun 30, 2009 at 4:27 PM, Tzury Bar Yochay > >> <[email protected]>wrote: > > >>> > If persistence is important, that is the right approach. We use > >>> > memcache for sessions at dealnews, but they are not ecommerce related > >>> > or > >>> > mission critical information. It's not worth the DB write for us. > > >>> High availability is the most important thing for us. Not persistence. > >>> If memcached is not the solution can anyone point out about other > >>> possible solutions? > >>> What would be the best way to have a session saved in more than one > >>> server? > > >> -- > >> "If you see a whole thing - it seems that it's always beautiful. Planets, > >> lives... But up close a world's all dirt and rocks. And day to day, life's > >> a > >> hard job, you get tired, you lose the pattern." > >> Ursula K. Le Guin > > >>http://www.finsel.com/words,-words,-words.aspx(My blog) - > >>http://www.finsel.com/photo-gallery.aspx(My Photogallery) - > >>http://www.reluctantdba.com/dbas-and-programmers/blog.aspx(My > >> Professional Blog) > > -- > > -- > > -Syed Ali
