# Resources and health checks

> Limit CPU and memory, watch usage, and restart apps that stop answering.

Source: https://quasar.achaverot.fr/docs/applications/resources-health/

## Usage

The **Overview** tab of an application shows its live CPU and memory use, and a history over the last 24 hours or 7 days.

For a compose stack, **Stack containers** lists each container with its own figures and logs.

## Resource limits

Limits keep one application from starving the server:

- over its **CPU** limit, an app is slowed down;
- at its **memory** limit, the kernel kills it instead of letting it take the whole server down.

Set them in **Overview → Container resources**, in cores and MB. Empty or `0` means unlimited.

| Change | When it applies |
| --- | --- |
| Setting or changing a limit | Immediately, on the running container. |
| Removing a limit | At the next deployment. Docker can't lift a limit from a running container. |

The panel says when a redeploy is still needed.

:::note
Limits set in Quasar don't apply to compose stacks. Use `deploy.resources.limits` on each service in the compose file.
:::

## Health checks

A health check regularly requests a path of your app over HTTP, and restarts the app when it stops answering.

1. On the application's page, open **Settings → Health check**.
2. Enter a path, such as `/health`.
3. Save.

The path is checked every 30 seconds. After **3 failures in a row**, the container is restarted, and a [notification](/server/notifications/) is sent.

Leave the path empty to turn the check off.