| title: | Scheduler |
|---|---|
| description: | The scheduler starts and manages containers. |
The scheduler is responsible for creating, starting, stopping, and destroying
app :ref:`Containers <container>`. For example, a command such as
deis scale cmd=10 tells the scheduler to run ten containers from the
Docker image for your app.
The scheduler must decide which machines are eligible to run these container jobs. Scheduler backends vary in the details of their job allocation policies and whether or not they are resource-aware, among other features.
The Deis scheduler is implemented in the :ref:`controller` component. The scheduler implementation (or "backend") can be changed dynamically to support different strategies or cluster types.
Follow the :ref:`choosing_a_scheduler` guide to learn about available options for the Deis scheduler.