Booting

When deploying to large numbers of hosts, you might prefer not to restart your services on every host at the same time.

Kamal’s default is to boot new containers on all hosts in parallel. However, you can control this with the boot configuration.

boot:

The number or percentage of hosts to boot at a time.

This can be an integer (e.g., 3) or a percentage string (e.g., 25%).

  limit: 25%

The number of seconds to wait between booting each group of hosts.

  wait: 10

Whether to boot roles in parallel on a host.

If a host has multiple roles, control whether they are booted in parallel or sequentially on that host.

Defaults to false.

  parallel_roles: true