I have been experimenting with Pacemaker & Corosync for a HA setup. I installed it on two Ubuntu 14.04 Linode's and after a lot of back and forth on outdated config examples and tutorials, managed to get it up and running. This mostly due to the fact that I had to set it to use UDP Unicast for it to work(Multicast and Broadcast won't work on Linode's network)
Both nodes are able to see each other, and they detect when the other one goes down. Great!
Now I want to try to add a third node while the cluster is running, so I go hunting for some command to do so... No...Nope... This seemingly crucial and simple action is, as far as I can tell, not possible with a simple command.
To add a node you have to add it to the config of every single node, and then shut down the cluster, reload, and start it back up. There goes High-Availability out of the window.
The only way to dynamically add node that I could find, was under cmap_keys(8).
I have to first run a command to find the next free node id. Then, for each node currently in the cluster, manually add it to nodelist.node.x.ringy_addr, and so on. Even after all that it will not survive a restart, I also have to update each and every config file, manually. THEN I have to copy the new config file to the new node, and start it up.
It is possible to connect to any of the nodes in the cluster, give a command to change existing nodes, and add resources, and these will be synced between all nodes. But I can't simply add a new node in the same way?
Please, someone tell me I'm just bad at googling information, and there is a simple command to add new nodes in a live, running HA cluster. Is there some tool or method I have overlooked?
Thank you for your time!