Lost task tracker and Could not obtain block errors

[John Conwell <jo...@iamjohn.me>]

I'm running into a wall with one of my map reduce jobs (actually its a 7
jobs, chained together).  I get to the 5th MR job, which takes as input the
output from the 3rd MR job, and right off the bat I start getting "Lost task
tracker" and "Could not obtain block..." errors.  Eventually I get enough of
these errors that hadoop just kills my tasks, and fails the job all
together.

I'm running a 5 node hadoop cluster on EC2.  The input to the 5th MR job is
~400mb in size (10 part-* files, each ~40mb in size), so its not really that
big.  And I seem to get this no matter how big a hdfs cluster I create (5 -
15 nodes).

I'm not really sure how to proceed in trouble shooting the issue.  Any help
would be greatly appreciated.

-- 

Thanks,
John C