Clarifying GameLift pricing, costs, and best practices for saving money

Instance usage is billed from the time your server is ACTIVE (ie ready to host game sessions) to the time you terminate it in GameLift (TERMINATED)

• For Linux this is per second billing.
• For Windows this is to the nearest hour https://aws.amazon.com/gamelift/faq/ "Billing begins when you allocate Amazon GameLift capacity and Amazon GameLift launches your game’s server binary for the first time on each instance. Billing concludes when you stop instances. For Windows instances, which are billed per instance-hour, partial instance-hours consumed are billed as full hours. For Linux instances, which are billed per instance-second, there is a 1 minute minimum charge per-instance."

So if you have a server thats in an ACTIVE state in GameLift, you are paying for it even if its idle waiting for GameSessions.

Use of spot fleets is entirely about your acceptance of risk. Spot instances are EC2 selling its spare capacity in a region, as demand grows, this spare capacity will be absorbed and Spot instances will be harder to get and potentially subject to termination.

If you are using FleetIQ it will prioritize placement on the Spot fleets (as long as GameLift is not seeing interruptions on that instance type in the regions). But at some point Spot interruptions may occur.

If you have an OnDemand Fleet then FleetIQ will potentially start placing on that fleet and so in this way you are sheltered from Spot instance interruptions.

Luckily games demand runs counter to business demands (high in the day, low in the evenings mostly) so theres generally a decent amount of Spot capacity unless you are using very large instances. Not sure what the official data shows, but for many developers interruption rates are very low (I thought there was a GDC talk related to this but I can't find it right now that has someone's actual data)

• The best thing to do is measure this yourself and see (easier said than done of course) but GameLift provides interruption metrics on the dashboard.

I wish there was a perfect formula here as in if you are doing x then use y. I know, GameLift wants to make it easy to use Spot and take some of the guesswork out of this so I would suspect more changes would be coming in the future in this space.

tldr: you save a huge amount of money using Spot + Linux + Concurrent Executions.

The amount of spare capacity you carry in your fleets is really up to you and how quickly traffic ramps up for you. The first useful metric is to work out how long a new server takes to activate for you. If you're out of capacity this is the worst case time for players to wait for a new session.

If you are small developer, this may be a trade off you are willing to take/have to take because you don't want to pay for that spare capacity (again Spot makes that a little easier to swallow).

Hope that makes some sense. I don't officially represent the GameLift service and if you have further questions, you should feel to reach out to them via AWS Support esp if you want the official GameLift answers on these things.

I am happy to keep answering your questions thought ;)