How manage units
To deploy a single unit of PgBouncer using its default configuration:
juju deploy pgbouncer --channel 1/stable
Scale units
PgBouncer is a subordinated charm, both scaling-up and scaling-down operations are performed via the principal charm using juju add-unit:
juju add-unit <principal_charm> -n <desired_num_of_units>
The subordinated charm will be scaled automatically, following the principal charm.