For the moment, Reddit is using Cassandra just for persistent cache, which implies high read/write ratio. Also it seems most of reads are done from the memory

For the moment, Reddit is using Cassandra just for persistent cache, which implies high read/write ratio. Also it seems most of reads are done from the memory anyways (they mentioned 6GB RAM for 94% of their database in old memcachedb setting [1]). So much less stress on I/O for this particular use-case. [1] http://blog.reddit.com/2010/03/and-fun-weekend-was-had-by-all.html http://blog.reddit.com/2010/03/and-fun-weekend-was-had-by-al...