One way Passwordless SSH from Master to worker nodes:
1. Generate Key:
ssh-keygen -t rsa
2. Create folder in worker node:
ssh [user]@255.255.255.255 mkdir -p .ssh
3. Copy key to worker node:
ssh-copy-id id_rsa.pub [user]@255.255.255.255
4. Enable permissions to worker:
ssh [user]@255.255.255.255 "chmod 700 .ssh; chmod 640 .ssh/authorized_keys"
700 — user can read, write and execute. group and others have no permissions
640 — user can read and write. group can read. others have no permissions
Configuration Files: (For minimal configuration)
core-site.xml configuration should be the same for master and all worker nodes. Namenode URL (fs.default.name) should point to master node only.
mapred-site.xml should be edited only on master node.
yarn-site.xml should be the same configuration on master and worker nodes.
the file “slaves” should be updated only in the master node.
hdfs-site.xml is self explanatory
IPV4 – Internet Protocol Version 4 — IP address follows this pattern:
IPV6 – Internet Protocol Version 6 — IP address follows this pattern:
Hadoop works/communicates on IPV4 within its cluster. It does not support IPV6 at the moment.