just:out, just:connect and Just Live/Just Play can be installed on a single machine, but there are several advantages when using separate machines for the UI and the engine:
- The actual CPU/GPU load is distributed (load balancing).
- The engine cannot be affected by user mistakes.
- Using multiple machines allows for additional fail-over for the playout components. just:connect allows you to configure a slave engine for each layer (video or FX layers). This means another physical machine takes the place of a failing machine.
When using multiple Just Live/Just Play instances to control the same channel it is possible to work simultaneously on a channel on a first-come first-served basis. Separating the UI from the engine also allows the user working on the machine which runs the Just Live/Just Play UI to turn off the machine without interrupting the playout.