hadoop on vmware, namenode not finding slaves

Question

I set up 3 identical linux (CentOS) servers on Vmware. Basically built one and made 2 fully clones.

I edit each servers hostnames : server1, server2,server3 and added them to each other hosts. Worked with ssh and enabled passwordless ssh. server1 # ssh server2 server2 #

So this works.

Formatted the dfs on the namenode. started the dfs and map-reduce. when i run
$ hadoop dfsadmin -report

it doesnt show any slaves.

what s going on?

any ideas?

Answer 1

Whenever I had this issue, I would be getting namespace collisions on the slave nodes. To resolve this, I deleted everything under each node's temp directory, then reformatted the namenode. Starting the DFS at this point usually did the trick.