The two part articles On HBase is a must read if you are interested in NoSQL technology.

• Why we’re using HBase: Part 1
• Why we’re using HBase: Part 2

HBase is more complex than other systems (you need Hadoop, Zookeeper, cluster machines have multiple roles). We believe that for HBase, this is not accidental complexity and that the argument that “HBase is not a good choice because it is complex” is irrelevant. The advantages far outweigh the problems. Relying on decoupled components plays nice with the Unix philosophy: do one thing and do it well.

There has been quite a bit of war going on between Cassandra and HBase and of course, they have different design philosophies (first one give emphasis on Consistency while other for Availability under CAP theorem)

Happy Reading!