For R connectivity, using NOSQL options for clustering and parallelization using Redis, Cassandra, Couch, MongoDB, MYSQL, Hadoop with HBase
I have a completed my R source code walkthroughs of 14 popular forecasting models for my membership. Now I focus on my cluster to speed up the simulations of the algos. As a result, it always comes down to how R talks to the popular NOSQL options out there. It seems I have narrowed it down to MongoDB and Redis. There are really not decent client R code examples for Hadoop, Couch, or Cassandra. Here are some links that making me lean towards Redis.
Comparing MongoDB and Redis, Part 1
Plus the client coding examples for Redis is much more helpful.
Update: It looks like I am going with MongoDB as I have 3 32 bit Macs. There is a limitation of 2 gb with Mongo but at least they can be used. MYSQL does not support older versions of OSX as well Redis is really Linux only. Too bad on the Redis side because it looked awesome!