Manage Scaling an Amazon GameLift Servers Fleet To/From Zero - Amazon GameLift Servers
Scale-in behaviorScale-out behaviorConfiguring Scale To/From ZeroBest practices
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Manage Scaling an Amazon GameLift Servers Fleet To/From Zero

Amazon GameLift Servers supports automatic scaling to and from zero instances based on game session activity. This managed capacity option allows your Fleet locations to scale-in to zero instances following a defined period of no game session activity and automatically scale-out when game sessions are requested.

Scaling to and from zero instances provides several advantages:

  • Cost optimization – Eliminate compute costs during periods of inactivity by running zero instances when there is no game session activity.

  • Automatic reactive scale-out – Fleets locations automatically scale-out to one instance when a game session is requested, eliminating the need for manual intervention.

  • Simplified management – No need to manually adjust Fleet capacity to/from zero based on anticipated player demand or development needs.

When you enable Scale To/From Zero on a fleet, Amazon GameLift Servers monitors game session activity and automatically adjusts Fleet capacity:

  • Scale-in to zero – After a configured period with no game sessions activity, Amazon GameLift Servers scales-in the Fleet location to zero instances.

  • Scale-out from zero – When a game session creation request is received, Amazon GameLift Servers scales-out the Fleet location to one instance, allowing auto scaling to resume.

  • Continued scaling – Following scale-out the fleet resumes using configured auto scaling policies to manage capacity.

Scale-in behavior

Amazon GameLift Servers begins the scale-in process for a Fleet location after the configured inactivity period has elapsed with no game session activity. This is defined as a period where::

  • There are no active game sessions in the Fleet location.

  • No requests have been made to create new game sessions in the Fleet location.

During scale-in, Amazon GameLift Servers will set minimum and desired capacity for the Fleet location to zero, rapidly scaling-in for cost savings.

Scale-out behavior

When a game session creation request is received while the Fleet location is at zero instances:

  • Amazon GameLift Servers immediately initiates scale-out of one instance.

  • Attempted placement of the game session may continue with other Fleets or Fleet locations, depending on configuration of Queues (if used).

Note

Scale-out from zero takes time to provision and initialize instances. Players may experience longer wait times for the first game session after a period of inactivity. For this reason this feature is best paired with multi-location Fleets and/or Queues.

Configuring Scale To/From Zero

Scaling To/From Zero is configured by updating an existing fleet.

Console

  1. Open the Amazon GameLift Servers console.

  2. In the navigation pane, choose Hosting, Fleets.

  3. On the Fleets page, choose the name of an active fleet to open the fleet's detail page.

  4. Under Scaling, select each location for which you want to configure scale to/from zero, and then choose Edit.

  5. In the Edit scaling capacity dialog box, select "Automatic" for Minimum capacity strategy, set your preferred value in minutes for Set minimum capacity to 0 after and then choose Confirm.

Amazon GameLift Servers will then scale-in the selected fleet locations to 0 instances once there has been no game session activity for the configured duration. Following this, when a request for a game session is made in this location, Amazon GameLift Servers will scale-out one instance as quickly as possible. This process will take a little time.

Amazon CLI

  • Configure scale to/from zero. In a command line window, use the update-fleet-capacity command with the fleet ID, location and managed capacity configuration to configure scale to/from zero. 

    aws gamelift update-fleet-capacity \
                                --fleet-id <fleet identifier> \
                                --location <location name> \
                                --managed-capacity-configuration ScaleInAfterInactivityMinutes=60,ZeroCapacityStrategy=SCALE_TO_AND_FROM_ZERO

    Example:

    aws gamelift update-fleet-capacity \
                                --fleet-id fleet-2222bbbb-33cc-44dd-55ee-6666ffff77aa \
                                --location us-west-2 \
                                --desired-instances 5 \
                                --max-size 10 \
                                --managed-capacity-configuration ScaleInAfterInactivityMinutes=60,ZeroCapacityStrategy=SCALE_TO_AND_FROM_ZERO

If your request is successful, Amazon GameLift Servers returns the updated capacity configuration. Amazon GameLift Servers will then scale-in the selected fleet locations to 0 instances once there has been no game session activity for the configured duration. Following this, when a request for a game session is made in this location, Amazon GameLift Servers will scale-out one instance as quickly as possible. This process will take a little time.

Best practices

Consider the following recommendations when using Scale To/From Zero:

  • Set appropriate inactivity periods – Balance cost savings against the frequency of scale-in/scale-out cycles. Shorter wait time to scale to zero may maximize savings, but would result in more frequent cold starts.

  • Use with predictable workloads – Scale To/From Zero works best for games with clear periods of inactivity, such as development/test environments or games with distinct off-peak hours.

  • Monitor CloudWatch metrics – Track fleet scaling events and game session placement times to optimize your configuration.

  • Combine with scaling policies – Use Scale To/From Zero alongside target-based or rule-based auto scaling for comprehensive capacity management.