Experience with Hadoop?

Question

Have any of you tried Hadoop? Can it be used without the distributed filesystem that goes with it, in a Share-nothing architecture? Would that make sense?

I\'m also inte

Answer 1

Hadoop MapReduce can run ontop of any number of file systems or even more abstract data sources such as databases. In fact there are a couple of built-in classes for non-HDFS filesystem support, such as S3 and FTP. You could easily build your own input format as well by extending the basic InputFormat class.

Using HDFS brings certain advantages, however. The most potent advantage is that the MapReduce job scheduler will attempt to execute maps and reduces on the physical machines that are storing the records in need of processing. This brings a performance boost as data can be loaded straight from the local disk instead of transferred over the network, which depending on the connection may be orders of magnitude slower.