Big Wins Processing Big Data: Behind the Scenes with Big Data at Torbit (torbit.com)

In general, Golang lets you code at higher level without compromising performance.

Both Go and Java are more likely going to have a faster development cycle for many developers than C++ and are less likely to have memory management bugs because they are garbage collected and memory safe[1]. Compared to many languages like Ruby, Python, etc all three of those are "high performance" languages. With a lot of optimization C++ has the potential to probably be the "fastest" solution. It all comes down to balancing execution performance, memory efficiency and development maintenance efforts.

While Go is a young language, I find working in it to be extremely productive, it makes concurrency easy to implement and get right, and produces application with good run-time characteristics.

[1]: http://en.wikipedia.org/wiki/Memory_safe

It is just an internal project name. If we open source the map reduce library we can always rename it.