On Mon, Jun 20, 2011 at 4:13 PM, <praveen.pe...@nokia.com> wrote: > Hi David, > Thanks for the response. I didn't specify anything for no. of concurrent > mappers but I do see that it shows as 10 on 50030 (for 5 node cluster). So I > believe hadoop is defaulting to no. of cores in the cluster which is 10. > That is why I want to choose the map tasks also same as no. of cores so that > they match with max concurrent map tasks. > > The maximum number of simultaneous mappers and reducers across the cluster are determined by your config. You are seeing capacity as 10 mappers since you probably have a default mapred-site.xml file. The default max jobs per task tracker is 2.
http://hadoop.apache.org/common/docs/r0.20.0/mapred-default.html Sridhar
