[Further update: At the request of the Facebook Data team, Mason Porter has taken down the data --- both the Facebook5 and the Facebook100. I hope you downloaded it before it disappeared.]
"I typically use Cassandra with caching in Redis if Cassandra's own read performance is too high latency. Writes and deletes are already low-latency in Cassandra. If your data doesn't need to be durable, just use Redis. Both of those systems work well with the key and value sizes you have and can sc