What I do is write single-threaded programs that process only a section of data, and manage them with HTCondor. It's some extra overhead and complexity but this

What I do is write single-threaded programs that process only a section of data, and manage them with HTCondor. It's some extra overhead and complexity but this way you can easily scale to hundreds of machines without changing anything. You also get mature queuing and job management tools that work independently of your program. If your application is easy to paralellize and you might need more than one machine i highly reccommend this route.