Debug managed EC2 fleets for Amazon GameLift Servers Realtime - Amazon GameLift Servers
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Debug managed EC2 fleets for Amazon GameLift Servers Realtime

This topic provides guidance on how to resolve issues with your Amazon GameLift Servers managed EC2 fleets for Realtime servers. For general troubleshooting help with managed EC2 fleets, see also Debug Amazon GameLift Servers fleet issues .

Zombie game sessions: They start and run a game, but they never end.

You might observe this issues as any of the following scenarios:

  • Script updates are not picked up by the fleet's Realtime servers.

  • The fleet quickly reaches maximum capacity and does not scale down when player activity (such as new game session requests) decreases.

This is almost certainly a result of failing to successfully call processEnding in your Realtime script. Although the fleet goes active and game sessions are started, there is no method for stopping them. As a result, the Realtime server that is running the game session is never freed up to start a new one, and new game sessions can only start when new Realtime servers are spun up. In addition, updates to the Realtime script do not impact already- running game sessions, only ones.

To prevent this from happening, scripts need to provide a mechanism to trigger a processEnding call. As illustrated in the Amazon GameLift Servers Realtime script example, one way is to program an idle session timeout where, if no player is connected for a certain amount of time, the script will end the current game session.

However, if you do fall into this scenario, there are a couple workarounds to get your Realtime servers unstuck. The trick is to trigger the Realtime server processes—or the underlying fleet instances—to restart. In this event, Amazon GameLift Servers automatically closes the game sessions for you. Once Realtime servers are freed up, they can start new game sessions using the latest version of the Realtime script.

There are a couple of methods to achieve this, depending on how pervasive the problem is:

  • Scale the entire fleet down. This method is the simplest to do but has a widespread effect. Scale the fleet down to zero instances, wait for the fleet to fully scale down, and then scale it back up. This will wipe out all existing game sessions, and let you start fresh with the most recently updated Realtime script.

  • Remotely access the instance and restart the process. This is a good option if you have only a few processes to fix. If you are already logged onto the instance, such as to tail logs or debug, then this may be the quickest method. See Remotely connect to Amazon GameLift Servers fleet instances.

If you opt not to include way to call processEnding in your Realtime script, there are a couple of tricky situations that might occur even when the fleet goes active and game sessions are started. First, a running game session does not end. As a result, the server process that is running that game session is never free to start a new game session. Second, the Realtime server does not pick up any script updates.