Database

The database holds the cluster's configuration and its history. Every server reaches it.

Where it is recorded

sudo xema node role add database

This records which server holds it. It is recorded only: xema node apply never starts, stops or moves it, because moving it moves data with it. xema join and xema init set it up where it belongs.

xema node roles          # this server's roles, beside what is running
xema status              # every service on this server, running or not

How a server reaches it

xema database                                      # what this server connects to; never the password
sudo xema database connect --server <host> --user <user>

database connect records how this server reaches the database, checks it, and sets up the schema. The password is asked for rather than typed. A server joining a cluster is told this by its join token.

Upgrading its schema

sudo xema database upgrade --dry-run    # what this release would change
sudo xema database upgrade

xema upgrade does this as part of an upgrade.

Backing it up

sudo xema backup

Run on the server that holds the database. See backups.

When its server's address changes

sudo xema node address <server> <new address>

Run on the server that moved.