One of my colleagues has been questioning me as to why Spark/HDFS makes no attempts to try to co-locate related data blocks. He pointed to this paper: http://www.vldb.org/pvldb/vol4/p575-eltabakh.pdf from 2011 on the CoHadoop research and the performance improvements it yielded for Map/Reduce jobs.
Would leveraging these ideas for writing data from Spark make sense/be worthwhile?
