There are 0 datanode(s) running and no node(s) are excluded in this operation

Question

I have set up a multi node Hadoop Cluster. The NameNode and Secondary namenode runs on the same machine and the cluster has only one Datanode. All the nodes are configured o

Answer 1

On my situation, firewalld service was running. It was on default configuration. And it don't allow the communication between nodes. My hadoop cluster was a test cluster. Because of this, I stopped the service. If your servers are in production, you should allow hadoop ports on firewalld, instead of

service firewalld stop
chkconfig firewalld off