Allocation re-architecture

[dgkanatsios]

Thundernetes allocation service currently works by finding a random StandingBy server and transitioning it to Active. We should consider the pros/cons of this approach and decide on alternative allocation methods, taking into account the environment that thundernetes is running (cloud provider/on-prem).

Moreover, the use of .Update to transition the game server to Active will return errors in case the GameServer has been deleted or crashed and the cache has not been updated. We should retry ourselves (at least once) in the allocation method.

[dgkanatsios]

I’ve been thinking about this recently and my proposal is to try and allocate to the game servers that reside on the newest Nodes. In cloud environments, this would have the effect of making sure the oldest Nodes get as less active game servers as possible, so in the event of a cluster scale down, they would be the ones to be deleted first. Result of this is that on a scale up, fresh/updates Nodes will pop up and be added to the cluster.

This would require an extra field on the GameServer that would designate the Node’s age. During allocation, we should sort the standingBy game servers by Node’s age and allocate on the newest ones.