# Resource Limits

Source: https://next.coolify.io/docs/databases/configuration/resource-limits

Open a database resource, then select **Resource Limits** to restrict the CPU and memory available to its container.

Start with measured database usage and leave enough capacity for startup, backups, compaction, and query bursts. A limit that is too low can make a healthy database appear unavailable.

## CPU limits

| Setting        | Accepted value                                   | Default | Behavior                                                    |
| :------------- | :----------------------------------------------- | :-----: | :---------------------------------------------------------- |
| **CPU limit**  | A whole or decimal number, such as `2` or `0.5`. |   `0`   | Maximum CPU capacity. `0` means no configured limit.        |
| **CPU set**    | CPU numbers or ranges, such as `0-2` or `0,1,3`. |  Empty  | Restricts the container to selected CPU cores.              |
| **CPU weight** | A whole number of `0` or greater.                |  `1024` | Relative CPU priority when containers compete for CPU time. |

**CPU weight** changes priority during contention; it does not reserve CPU capacity.

## Memory limits

Memory fields accept `0` or a number followed by `b`, `k`, `m`, or `g`, such as `256m` or `1g`.

| Setting                   | Default | Behavior                                                                         |
| :------------------------ | :-----: | :------------------------------------------------------------------------------- |
| **Memory reservation**    |   `0`   | Memory reservation used during server memory pressure.                           |
| **Swappiness**            |   `60`  | Value from `0` to `100` controlling how readily anonymous memory can be swapped. |
| **Memory limit**          |   `0`   | Hard memory limit for the container.                                             |
| **Memory and swap limit** |   `0`   | Total memory and swap available to the container.                                |

`0` means no configured limit for the CPU and memory limit fields. Set an explicit limit only when you understand the database's memory behavior and the server's available capacity.

> **Warning: Low limits can stop a database**
>
> A database that reaches its hard memory limit can be terminated by Docker. A low CPU limit can also make startup, health checks, backups, or queries time out. Review **Runtime Logs**, **Metrics**, and health status after applying a limit.

## Apply and verify

Select **Save changes**, then restart or redeploy the database so the container starts with the new limits.

After it starts:

1. Open **Metrics** and check CPU and memory usage.
2. Open **Runtime Logs** for out-of-memory exits, repeated restarts, or failed startup messages.
3. Run a representative application query and a backup, when supported.