It's really weird and confusing me. Anyone can help this question? Thanks!
2013/10/16 sam liu <samliuhad...@gmail.com> > Hi Experts, > > In Hadoop-2.0.4, the TeraSort leverage TeraSort#TotalOrderPartitioner as > its Partitioner: 'job.setPartitionerClass(TotalOrderPartitioner.class);'. > However, seems Yarn did not execute the methods of > TeraSort#TotalOrderPartitioner at all. I did some tests to verify it as > below: > > Test 1: Add some code in the method readPartitions() and setConf() in > TeraSort#TotalOrderPartitioner to print some words and write some word to a > file. > Expected Result: Some words should be printed and wrote into a file > Actual Result: No word was printed and wrote into a file at all > > Test 2: Remove all existing methods in TeraSort#TotalOrderPartitioner, but > only remaining some necessary but empty methods in it > Expected Result: TeraSort job will ocurr some exception, as the specified > Partitioner is not implemented at all > Actual Result: TeraSort job completed successfully without any exception > > Above tests confused me a lot, because seems Yarn never use specified > partitioner TeraSort#TotalOrderPartitioner at all during job execution. > > Any one can help provide the reasons? > > Thanks very much! >