Allocation spread#

Allocation spread is a feature that enables the allocation system to spread requests across multiple machines instead of just a single hot machine. Game Server Hosting accomplishes this with a fleet configuration value called allocation spread.

The allocation spread value represents the maximum number of machines that the reactive scaling system spreads allocations across machines in a fleet or fleet region.

The primary benefit of spreading allocations out across a set of machines instead of a single machine is that you’re less likely to run into a scenario where you're starting multiple game servers on a single machine in a short time. Each time you make an allocation request and a machine fulfills that request with a game server, Game Server Hosting has to either start or restart that game server process for the new game session. Game servers consume more resources when they initially start up, so starting multiple game servers on the same machine in quick succession might cause performance issues for players connecting to those game servers.

The allocation spread value can be any integer equal to or higher than one.

If the allocation spread value is one, it has no effect on how Game Server Hosting allocates across machines, and the allocation system uses a single hot machine to fulfill allocation requests until the hot machine is full. Taking this approach might benefit customers with game server processes that don’t consume a lot of resources when starting up because it reduces the time to descale game servers.

One out of 20 server slots used on the hot machines in a fleet with an allocation spread of one.

19 out of 20 server slots used on the hot machine in a fleet with an allocation spread of one.

All 20 server slots used on the previous hot machine, so the reactive scaler selects a new hot machine, which now has one out of 20 server slots used.

If the allocation spread value is higher than one, the allocation system spreads the allocations across a random number of machines between 1 and N, where N is the allocation spread value. The following diagram shows an example where the allocation spread is three, so the reactive scaler spreads the allocation across three hot machines.

One out of 20 server slots used on one of the three hot machines in a fleet with an allocation spread of three.

One out of 20 server slots used on two of the three hot machines in a fleet with an allocation spread of three.

Specifying an allocation spread value that's higher than the number of bare metal machines can't result in additional scaling, but might cause the reactive scaling system to keep machines online longer.