Command add-unit

Usage: juju add-unit [options] <application name>

Summary:

Adds one or more units to a deployed application.

Options:

--attach-storage (= )

Existing storage to attach to the deployed unit (not available on kubernetes models)

-m, --model (= "")

Model to operate in. Accepts [<controller name>:]<model name>

-n, --num-units (= 1)

Number of units to add

--to (= "")

The machine and/or container to deploy the unit in (bypasses constraints)

Details:

The add-unit is used to scale out an application for improved performance or availability.

The usage of this command differs depending on whether it is being used on a Kubernetes or cloud model.

Many charms will seamlessly support horizontal scaling while others may need an additional application support (e.g. a separate load balancer). See the documentation for specific charms to check how scale-out is supported. For Kubernetes models the only valid argument is -n, --num-units.

Anything additional will result in an error.

Example:

Add five units of mysql:

     juju add-unit mysql --num-units 5

For cloud models, by default, units are deployed to newly provisioned machines in accordance with any application or model constraints.

This command also supports the placement directive (--to) for targeting specific machines or containers, which will bypass application and model constraints.

Examples:

Add five units of mysql on five new machines:

juju add-unit mysql -n 5

Add a unit of mysql to machine 23 (which already exists):

juju add-unit mysql --to 23

Add two units of mysql to existing machines 3 and 4:

juju add-unit mysql -n 2 --to 3,4

Add three units of mysql, one to machine 3 and the others to new machines:

juju add-unit mysql -n 3 --to 3

Add a unit of mysql into a new LXD container on machine 7:

juju add-unit mysql --to lxd:7

Add two units of mysql into two new LXD containers on machine 7:

juju add-unit mysql -n 2 --to lxd:7,lxd:7

Add a unit of mysql to LXD container number 3 on machine 24:

juju add-unit mysql --to 24/lxd/3

Add a unit of mysql to LXD container on a new machine:

juju add-unit mysql --to lxd

See also:

remove-unit