Thank you! Just to confirm. Consider a JVM (that is being reused), has
to reduce K1,{V11,V12,V13..} and K2,{V21,V22,V23,....}. Then the
configure and close methods are called once each for both K1,{V11,...}
and K2,{V2,....}?Is my understanding correct? Once again, there is no combiner, and it makes sense that it is not called. Thank you Saptarshi On Mon, Jun 22, 2009 at 10:55 PM, jason hadoop<jason.had...@gmail.com> wrote: > configure and close are run for each task, mapper and reducer. The configure > and close are NOT run on the combiner class. > > On Mon, Jun 22, 2009 at 9:23 AM, Saptarshi Guha <saptarshi.g...@gmail.com> > wrote: >> >> Hello, >> In a mapreduce job, a given map JVM will run N map tasks. Are the >> configure and close methods executed for every one of these N tasks? >> Or is configure executed once when the JVM starts and the close method >> executed once when all N have been completed? >> >> I have the same question for the reduce task. Will it be run before >> for every reduce task? And close is run when all the values for a >> given key have been processed? >> >> We can assume there isn't a combiner. >> >> Regards >> Saptarshi > > > > -- > Pro Hadoop, a book to guide you from beginner to hadoop mastery, > http://www.amazon.com/dp/1430219424?tag=jewlerymall > www.prohadoopbook.com a community for Hadoop Professionals >
