So how does reducer obtain the mapper's output ? Does it make a network call and read data from mappers local storage or does the mapper send the data ?
Thanks, Aishwarya On Sat, May 28, 2011 at 6:08 PM, jagaran das <jagaran_...@yahoo.co.in>wrote: > Mappers write to local persistance and reducers write to hdfs > > - Jagaran > > > > ________________________________ > From: Aishwarya Venkataraman <avenk...@cs.ucsd.edu> > To: common-dev@hadoop.apache.org > Sent: Sat, 28 May, 2011 4:11:13 PM > Subject: Question regarding network data transfer > > Hello, > > Where exactly(Java class) does the network data transfer happen from a > mapper to a reducer ? Mapper seems to be writing data to the HDFS. Does > reducer read data from the mapper's HDFS over the network ? This is evading > me. Thanks in advance for the help. > > Cheers, > Aishwarya > -- Thanks, Aishwarya Venkataraman avenk...@cs.ucsd.edu Graduate Student | Department of Computer Science University of California, San Diego
