ltcluster requires that the database defined in the conninfo setting contains the ltcluster extension. The database user defined in the conninfo setting must be able to access this database and the database objects contained within the extension.

The ltcluster extension can only be installed by a superuser. If the ltcluster user is a superuser, ltcluster will create the extension automatically.

Alternatively, the extension can be created manually by a superuser (with "CREATE EXTENSION ltcluster") before executing ltcluster primary register.