AAA, NAC, Guest Access & BYOD

Q:

Steps to check communication between AN node and compute nodes in hadoop cluster on Aruba IntroSpect

A quick way to check the communication between the AN node and all compute nodes that are part of hadoop cluster is to run the below Ansible command:

ansible all -a hostname

This command would help us identify which node is having issues within hadoop cluster and also lists the hostnames of all nodes in the cluster.

In case of broken communication between AN node and compute nodes, you would see the below response:

[root@ ~]# ansible all -a hostname

an-node | SUCCESS | rc=0 >>

is-tac.arubans.us

an-node.cluster-internal | SUCCESS | rc=0 >>

is-tac.arubans.us

cdh-4 | UNREACHABLE! => {

    "changed": false, 

    "msg": "Failed to connect to the host via ssh: ssh: connect to host cdh-4 port 22: No route to host\r
", 

    "unreachable": true

}

cdh-3 | UNREACHABLE! => {

    "changed": false, 

    "msg": "Failed to connect to the host via ssh: ssh: connect to host cdh-3 port 22: No route to host\r
", 

    "unreachable": true

}

cdh-1 | UNREACHABLE! => {

    "changed": false, 

    "msg": "Failed to connect to the host via ssh: ssh: connect to host cdh-1 port 22: No route to host\r
", 

    "unreachable": true

}

cdh-2 | UNREACHABLE! => {

    "changed": false, 

    "msg": "Failed to connect to the host via ssh: ssh: connect to host cdh-2 port 22: No route to host\r
", 

    "unreachable": true

}

[root@ ~]#