Comparison with MapReduce
One illuminating way to understand Spark is in terms of its advances over its prede-cessor，Apache Hadoop's MapReduce. MapReduce revolutionized computation overhuge datasets by offering a simple and resilient model for writing programs that couldexecute in parallel across hundreds to thousands of machines. It broke up work intosmall tasks and could gracefully accommodate task failures without compromisingthe job to which they belonged.