# 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 FARGATElong 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: v2.249.0 · 13 Apr 2026

## 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.CfnDaemonTaskDefinition.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.