Manager

Manager is the administration of the cluster: the Admin UI, the API behind it, and the changes made from it. Every xema command that changes the cluster's records goes through it.

A cluster always has one. When no server holds the role, xema node apply gives it to one, chosen the same way on every server so they all agree. After that it is never moved for you.

Putting it on a server

sudo xema node role add manager
sudo xema node apply

node role add records that this server should run it, and node apply starts it. If xema component list shows it is not installed here, install it between the two:

sudo xema component install manager

A server can also be given it as it joins: sudo xema join ... --roles manager,....

Taking it off

sudo xema node role remove manager
sudo xema node apply

Moving it to another server

Add it where it should be, then remove it from where it is:

sudo xema node role add manager      # on the new server
sudo xema node apply
sudo xema node role remove manager   # on the old one
sudo xema node apply

Checking it

xema node roles          # what this server should run, beside what it runs
xema status              # every service on this server, running or not
xema logs manager

Restarting it

sudo xema restart manager                       # on this server
sudo xema node restart manager --node <server>  # on another one

Restarting drops the calls it is carrying.