> **Experimental**
>
> `@aws-cdk/aws-gamelift-alpha` is an [**experimental**](/stability) (alpha) package: its API may change in any release, without a major version bump.
# RuntimeConfiguration

A collection of server process configurations that describe the set of processes to run on each instance in a fleet.

Server processes run either an executable in a custom game build or a Realtime Servers script.
GameLift launches the configured processes, manages their life cycle, and replaces them as needed.
Each instance checks regularly for an updated runtime configuration.

A GameLift instance is limited to 50 processes running concurrently.
To calculate the total number of processes in a runtime configuration, add the values of the `ConcurrentExecutions` parameter for each `ServerProcess`.

- Stability: [Experimental](/cdk/api/stability.html)
- Source: [`lib/fleet-base.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0-alpha.0/packages/@aws-cdk/aws-gamelift-alpha/lib/fleet-base.ts#L96)

## Example

```ts
declare const build: gamelift.Build;
// Server processes can be delcared in a declarative way through the constructor
const fleet = new gamelift.BuildFleet(this, 'Game server fleet', {
  fleetName: 'test-fleet',
  content: build,
  instanceType: ec2.InstanceType.of(ec2.InstanceClass.C4, ec2.InstanceSize.LARGE),
  runtimeConfiguration: {
    serverProcesses: [{
      launchPath: '/local/game/GameLiftExampleServer.x86_64',
      parameters: '-logFile /local/game/logs/myserver1935.log -port 1935',
      concurrentExecutions: 100,
    }]
  }
});
```

## Properties

- `gameSessionActivationTimeout`: [Duration](/cdk/api/v2/docs/aws-cdk-lib.Duration.html) = Duration.seconds(300) — The maximum amount of time allowed to launch a new game session and have it report ready to host players.

  During this time, the game session is in status `ACTIVATING`.

  If the game session does not become active before the timeout, it is ended and the game session status is changed to `TERMINATED`.

- `maxConcurrentGameSessionActivations`: number = no limit — The number of game sessions in status `ACTIVATING` to allow on an instance.

  This setting limits the instance resources that can be used for new game activations at any one time.

- `serverProcesses`: [ServerProcess](/cdk/api/v2/docs/@aws-cdk_aws-gamelift-alpha.ServerProcess.html)[] (required) — A collection of server process configurations that identify what server processes to run on each instance in a fleet.