I'm trying to copy data from an older cluster using 0.89 (CDH3b3) to a new
one using 0.91 (CDH3b4) using the CopyTable MR job but it always hangs on
"map 0% reduce 0%" until eventually the job is killed by Hadoop for not
responding after 600 seconds.
I verified that it works fine when copying from one table to another on the
same cluster and I verified that the servers in the source cluster have
network access to those in the destination cluster.
Any idea what could be causing it?