Facebook did a lot of work to keep their huge memcache cluster consistent and fault-tolerant. I think a cache infrastructure like Cassandra would make that a lot easier.
On Thu, Apr 29, 2010 at 11:54 AM, Lisen Mu <imm...@gmail.com> wrote: > > http://www.reddit.com/r/programming/comments/bcqhi/reddits_now_running_on_cassandra/ > > It seems to me that they are still using Cassandra in persistant storage > layer as a replacement of memcachedb, not in cache layer. > > I'm new here with Cassandra actually, but now I'm also curious about the > possibility of using cassandra as cache. > the main concern is repair-on-read strategy, the secondary is commitlog. > > If I'm correct about this, every read request to cassandra will trigger > several (N-1) message between cassandra nodes. > In our current traditional memcached + mysql set up, our intranet is kind > of busy already. I think It would be a burden if message is flooding between > memcached servers. > > In fact, In my opinion, what happend to our db is happening again in cache > layer: > > First, we have nonsql Cassandra, saver of the day. > But we are not going to let Cassandra carry the weight of page view > directly, so we still need cache. > Eventually we have to shard the cache to scale, and replicate to handle hot > spot. > In this stage, it would be a HUGE pity if we cannot reuse Cassandra's > exclusively outstanding ability of handling distribution problem. > > So why not provide a kind of Cassandra Daemon, so we can write adapter for > memcached etc. to construct a pure-in-memory distributed cache layer? > > On Tue, Apr 27, 2010 at 9:47 AM, Jonathan Ellis <jbel...@gmail.com> wrote: > >> On Mon, Apr 26, 2010 at 9:04 AM, Dominique De Vito >> <dominique.dev...@thalesgroup.com> wrote: >> > (1) has anyone already used Cassandra as an in-memory data grid ? >> > If no, does anyone know how far such a database is from, let's say, >> Oracle >> > Coherence ? >> > Does Cassandra provide, for example, a (synchronized) cache on the >> client >> > side ? >> >> If you mean an in-process cache on the client side, no. >> >> > (2) has anyone already used Cassandra as a distributed cache ? >> > Are there some testimonials somewhere about this use case ? >> >> That's basically what reddit is using it for. >> http://blog.reddit.com/2010/03/she-who-entangles-men.html >> >> -- >> Jonathan Ellis >> Project Chair, Apache Cassandra >> co-founder of Riptano, the source for professional Cassandra support >> http://riptano.com >> > >
