Hi Alicia ,

Cassandra input format creates mappers as many as vnodes. It is a known issue. You need to lower the number of vnodes :(

I have a simple solution for that and ready to write a patch. Should I create a ticket about that? I don't know the procedure about that.


On Thu, Mar 28, 2013 at 2:30 PM, Alicia Leong <lccalicia@gmail.com> wrote:
Hi All,

I have 3 nodes of Cassandra 1.2.3 & edited the cassandra.yaml for vnodes.

When I execute a M/R job .. the console showed HUNDRED of Map tasks.

May I know, is the normal since is vnodes?  If yes, this have slow the M/R job to finish/complete.