UpdateFleetCapacity

This API works with the following fleet types: EC2, Container

Updates capacity settings for a managed EC2 fleet or managed container fleet. For these fleets, you adjust capacity by changing the number of instances in the fleet. Fleet capacity determines the number of game sessions and players that the fleet can host based on its configuration. For fleets with multiple locations, use this operation to manage capacity settings in each location individually.

To update capacity for a fleet's home Region, or if the fleet has no remote locations, omit the Location parameter. The fleet must be in ACTIVE status.

To update capacity for a fleet's remote location, set the Location parameter to the location to update. The location must be in ACTIVE status.

If successful, Amazon GameLift Servers updates the capacity settings and returns the identifiers for the updated fleet and/or location. If a requested change to desired capacity exceeds the instance type's limit, the LimitExceeded exception occurs.

Updates often prompt an immediate change in fleet capacity, such as when current capacity is different than the new desired capacity or outside the new limits. In this scenario, Amazon GameLift Servers automatically initiates steps to add or remove instances in the fleet location. You can track a fleet's current capacity by calling DescribeFleetCapacity or DescribeFleetLocationCapacity.

Use ManagedCapacityConfiguration with the "SCALE_TO_AND_FROM_ZERO" ZeroCapacityStrategy to enable Amazon GameLift Servers to fully manage the MinSize value, switching between 0 and 1 based on game session activity. This is ideal for eliminating compute costs during periods of no game activity. It is particularly beneficial during development when you're away from your desk, iterating on builds for extended periods, in production environments serving low-traffic locations, or for games with long, predictable downtime windows. By automatically managing capacity between 0 and 1 instances, you avoid paying for idle instances while maintaining the ability to serve game sessions when demand arrives. Note that while scale-out is triggered immediately upon receiving a game session request, actual game session availability depends on your server process startup time, so this approach works best with multi-location Fleets where cold-start latency is tolerable. With a "MANUAL" ZeroCapacityStrategy Amazon GameLift Servers will not modify Fleet MinSize values automatically and will not scale out from zero instances in response to game sessions. This is configurable per-location.

Learn more

Scaling fleet capacity

Request Syntax

{
   "DesiredInstances": number,
   "FleetId": "string",
   "Location": "string",
   "ManagedCapacityConfiguration": { 
      "ScaleInAfterInactivityMinutes": number,
      "ZeroCapacityStrategy": "string"
   },
   "MaxSize": number,
   "MinSize": number
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

Response Syntax

{
   "FleetArn": "string",
   "FleetId": "string",
   "Location": "string",
   "ManagedCapacityConfiguration": { 
      "ScaleInAfterInactivityMinutes": number,
      "ZeroCapacityStrategy": "string"
   }
}

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The following data is returned in JSON format by the service.

Errors

For information about the errors that are common to all actions, see Common Errors.

Examples

Increase fleet capacity

This example requests an increase in fleet capacity and raises the maximum allowed instances to accommodate the request. Because no location is specified, the update is applied to the fleet's home Region (where the fleet was created), which is us-west-2. Note that a fleet's home Region is always identified in the fleet ARN.

HTTP requests are authenticated using an AWS Signature Version 4 signature in the Authorization header field.

Sample Request

{
   "FleetId": "arn:aws:gamelift:us-west-2::fleet/fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
   "DesiredInstances": 10,
   "MaxSize": 10
}

Sample Response

{
    "FleetArn":"arn:aws:gamelift:us-west-2::fleet/fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "FleetId": "fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "Location": "us-west-2",
    "ManagedCapacityConfiguration": {
        "ZeroCapacityStrategy": "MANUAL"
    }
}

Update capacity settings for a fleet's remote location

This example adjusts the minimum/maximum allowed instances for one remote location in a multi-location fleet. For fleets that use auto-scaling, allowed instance settings define the scaling range for a fleet location. In this example, the updates are being applied to the remote location sa-east-1.

HTTP requests are authenticated using an AWS Signature Version 4 signature in the Authorization header field.

Sample Request

{
    "FleetId": "arn:aws:gamelift:us-west-2::fleet/fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "Location": "sa-east-1",
    "MinSize": 10,
    "MaxSize": 100
}

Sample Response

{
    "FleetArn":"arn:aws:gamelift:us-west-2::fleet/fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "FleetId": "fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "Location": "sa-east-1",
    "ManagedCapacityConfiguration": {
        "ZeroCapacityStrategy": "MANUAL"
    }
}

Configure ManagedCapacityConfiguration to Scale to/from Zero

This example configures ManagedCapacityConfiguration such that fleet capacity will automatically scale in to zero following a period (60 minutes in this example) where no game sessions are placed on the fleet and will scale out from zero in response to game session activity.

HTTP requests are authenticated using an AWS Signature Version 4 signature in the Authorization header field.

Sample Request

{
    "FleetId": "arn:aws:gamelift:us-west-2::fleet/fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "ManagedCapacityConfiguration": {
        "ScaleInAfterInactivityMinutes": 60,
        "ZeroCapacityStrategy": "SCALE_TO_AND_FROM_ZERO"
    }
}

Sample Response

{
    "FleetArn":"arn:aws:gamelift:us-west-2::fleet/fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "FleetId": "fleet-1111aaaa-22bb-33cc-44dd-5555eeee66ff",
    "Location": "us-west-2",
    "ManagedCapacityConfiguration": {
        "ScaleInAfterInactivityMinutes": 60,
        "ZeroCapacityStrategy": "SCALE_TO_AND_FROM_ZERO"
    }
}

See Also

For more information about using this API in one of the language-specific AWS SDKs, see the following: