topic Re: Cluster Update Failed Because of same hostname for all nodes in Dynatrace Managed Q&A

Cluster Update Failed Because of same hostname for all nodes

gauresh_shinde — Thu, 20 Jul 2023 07:55:24 GMT

Hi All,

We have 3 node cluster but all node have same hostname in CMC. We want to change the hostname. Anyone has done please assist us. Currently it using domain name as hostname

Thanks,
Gauresh

Re: Cluster Update Failed Because of same hostname for all nodes

chris_v — Tue, 25 Jul 2023 03:51:05 GMT

Hi Gauresh,

The cluster nodes get their names from a self-lookup on the nodes themselves, when the naming appears wrong, it's usually because the nodes hosts file doesn't include the right details.

I suggest you look at the /etc/hosts file on each node, and if not present add a self-resolving (localhost/127.0.0.1) entry for each node. without knowing what may already be in the hosts file in your case, leave anything already in there alone.

so for example if you have three nodes named node1, node2, and node3, and your domain name is example.org add a line in each like the below.

on node 1's /etc/hosts:
127.0.0.1    node1 node1.example.org

on node 2's /etc/hosts:
127.0.0.1    node2 node2.example.org

on node 3's /etc/hosts:
127.0.0.1    node3 node3.example.org

The changes won't be picked up until after restarts, so don't worry if you don't see a change right away.

The same can be used for any Linux based ActiveGates you may have incorrect names for.

Re: Cluster Update Failed Because of same hostname for all nodes

gauresh_shinde — Fri, 28 Jul 2023 12:42:35 GMT

Is there any impact on Dynatrace setup?

Re: Cluster Update Failed Because of same hostname for all nodes

chris_v — Tue, 01 Aug 2023 01:51:35 GMT

No, the cluster uses the IP addresses for communications, the naming is just for us humans.

Re: Cluster Update Failed Because of same hostname for all nodes

Radoslaw_Szulgo — Mon, 07 Aug 2023 10:20:25 GMT

I'd be cautious with such a setup. I'm concerned it may cause OneAgent/ActiveGate communication issues, as hostnames will appear in the communication endpoint list. If the same domain is represented by multiple nodes it may cause instability, missed or incomplete data. It is recommended to have separate host names.