[ClusterLabs] Adding a node to the cluster deployed with "Unicast configuration"

[Jan Friesse]

Alejandro Comisario napsal(a):
> Hi everyone, i have a problem when scaling a corosync/pacemaker
> cluster deployed using unicast.
>
> eg on corosync.conf.
>
> nodelist {
> node {
> ring0_addr: 10.10.0.10
> nodeid: 1
> }
> node {
> ring0_addr: 10.10.0.11
> nodeid: 2
> }
> }
>
> Tried to add the new node with the new config (meaning, adding the new
> node) nad leaving the other two with the same config and started
> services on the third node, but doesnt seem to work until i update the
> config on the server #1 and #2 and restart corosync/pacemaker which
> does the obvious of bringing every resource down.
>
> There should be a way to "hot add" a new node to the cluster, but i
> dont seem to find one.
> what is the best way to add a node without bothering the rest ? or
> better said, what is the right way to do it ?

Adding node is possible with following process:
- Add node to config file on both existing nodes
- Exec corosync-cfgtool -R (it's enough to exec only on one of nodes)
- Make sure 3rd (new) node has same config as two existing nodes
- Start corosync/pcmk on new node

This is (more or less) how pcs works. No stopping of corosync is needed.

Regards,
   Honza

>
> PS: i can't implement multicast on my network.
>