How to make sure there is a new server available for hosting instance when all servers are busy with matches.

Hi,

The target based auto-scaling policy is supposed to address your use case. By setting the buffer to 15% GameLift will ensure scale up whenever the percentage of AvailableGameSessions goes below 15%. But since you've set the max as 9, GameLift will only scale upto 9 instances.

• A new instance will have processes that are capable of placing game sessions. To actually use these processes, you would have to call CreateGameSession or StartGameSessionPlacement before putting player sessions onto that game session. Have you verified that you are in fact creating new game sessions that players can utilize? Or are you attempting to place the new players onto the same game session that has the DENY_ALL policy?
• Have you verified the AvailableGameSessions metrics in the "Fleet metrics" tab on the console? This might help understand what's going on better.
• In addition to scaling, you can also create multiple game sessions on a single instance (maximum of 50 subjective to performance concerns). This can be done by setting the RuntimeConfiguration on the fleet.

If this is not behaving as expected, I'd recommend creating a support case so the service team can help further.

Thanks!