Datanode denied communication with namenode because hostname cannot be resolved
In my situation, I included three configuration to the namenode and datanode as well:
dfs.namenode.datanode.registratin.io-hostname-check: falsedfs.client.use.datanode.hostname: falsedfs.datanode.use.datanode.hostname: false
I hope you found a resolution to the issue by now.I ran into similar problem last week, but my cluster is set up in a different environment but the problem context is same.
Essentially , the reverse DNS lookup needs to be set up to solve this issue if the cluster is using a DNS Resolver then this needs to be set up at the DNS server level or if the Name Nodes are looking into /etc/hosts file to find Data Nodes then there needs to be any entry for the Data nodes there.
I have updated an old question in Hortonworks Community Forum Post,Link as below:https://community.hortonworks.com/questions/24320/datanode-denied-communication-with-namenode.html?childToView=135321#answer-135321