Server: Setup and licensing for cold standby (failover) application server
Do we need a license to set up a secondary server offsite?
Atlassian does not officially support ‘cold standby' setup so we do not have an official documentation for a failover server setup. But still, you can use any backup system and frequency you prefer and backup your production application and database to a secondary server off site where you have installed the same version of the application you are running in production. When your primary instance goes down and you want to switch your standby instance into production, you can do so at any time. This process is manual. Only our Data Center licenses support active-active clustering to automatically route traffic to another application node when server failure occurs.
For licensing, our FAQ suggests using free developer license that comes with each commercial license and can be generated and downloaded through your My Atlassian account (see How to use developer licenses and to whom are they available?). You can also use your production license if you would like. For all intents and purposes, your commercial license is allowed to run only on one production server at a time but when you run your cold standby (by default this means your primary production is down and not running) so you would still be within terms and conditions of Atlassian licensing.