The main issue (for me) when reading this article: there is no introduction. It starts to introduce Hadoop as if it is a brand new technology while it has been out there for years and is very well known in the niche of distributed map-reduce and related technologies.
It would improve a lot, if there would be a simple introduction that would state why it was written (e.g. no good comprehensive introduction currently available) and for whom it is intended. But even then, I'm not sure it is a good fit for TSS - just let people google for it, why post it here?
And, the title "Hadoop Compute Cluster: Summary" is also not exactly describing the contents. Summary of what? If it would be called "Quick introduction to Hadoop and friends" I would even consider not complaining about the missing introduction :-P
BTW, the author (Tejas Bavishi) seems to be specialized in writing (useless) introductions to already well-known technologies. Last time it was about Spring framework (http://www.theserverside.com/discussions/thread.tss?thread_id=61937) - and that had exactly the same problems. I wonder how is the moderation supposed to work on TSS?