# SystemControlProperty

A list of namespaced kernel parameters to set in the container.

This parameter maps to `Sysctls` in the docker container create command and the `--sysctl` option to docker run. For example, you can configure `net.ipv4.tcp_keepalive_time` setting to maintain longer lived connections.

We don't recommend that you specify network-related `systemControls` parameters for multiple containers in a single task that also uses either the `awsvpc` or `host` network mode. Doing this has the following disadvantages:

- For tasks that use the `awsvpc` network mode including Fargate, if you set `systemControls` for any container, it applies to all containers in the task. If you set different `systemControls` for multiple containers in a single task, the container that's started last determines which `systemControls` take effect.
- For tasks that use the `host` network mode, the network namespace `systemControls` aren't supported.

If you're setting an IPC resource namespace to use for the containers in the task, the following conditions apply to your system controls. For more information, see [IPC mode](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#task_definition_ipcmode) .

- For tasks that use the `host` IPC mode, IPC namespace `systemControls` aren't supported.
- For tasks that use the `task` IPC mode, IPC namespace `systemControls` values apply to all containers within a task.

> This parameter is not supported for Windows containers. > This parameter is only supported for tasks that are hosted on AWS Fargate if the tasks are using platform version `1.4.0` or later (Linux). This isn't supported for Windows containers on Fargate.

- Source: Generated code
- Type last changed: v2.93.0 · 23 Aug 2023

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_ecs as ecs } from 'aws-cdk-lib';
const systemControlProperty: ecs.CfnTaskDefinition.SystemControlProperty = {
  namespace: 'namespace',
  value: 'value',
};
```

## Properties

- `namespace`: string — The namespaced kernel parameter to set a `value` for.

- `value`: string — The namespaced kernel parameter to set a `value` for.

  Valid IPC namespace values: `"kernel.msgmax" | "kernel.msgmnb" | "kernel.msgmni" | "kernel.sem" | "kernel.shmall" | "kernel.shmmax" | "kernel.shmmni" | "kernel.shm_rmid_forced"` , and `Sysctls` that start with `"fs.mqueue.*"`

  Valid network namespace values: `Sysctls` that start with `"net.*"` . Only namespaced `Sysctls` that exist within the container starting with "net.* are accepted.

  All of these values are supported by Fargate.