Amazon GameLift
Developer Guide (Version )

Testing Your Integration

Use Amazon GameLift Local to run a limited version of the Amazon GameLift service on a local device and test your game integration against it. This tool is useful when doing iterative development on your game integration. The alternative—uploading each new build to Amazon GameLift and configuring a fleet to host your game—can take 30 minutes or more each time.

With Amazon GameLift Local, you can verify the following:

  • Your game server is correctly integrated with the Server SDK and is properly communicating with the Amazon GameLift service to start new game sessions, accept new players, and report health and status.

  • Your game client is correctly integrated with the AWS SDK for Amazon GameLift and is able to retrieve information on existing game sessions, start new game sessions, join players to games and connect to the game session.

Amazon GameLift Local is a command-line tool that starts a self-contained version of the Amazon GameLift service. Amazon GameLift Local also provides a running event log of server process initialization, health checks, and API calls and responses. Amazon GameLift Local recognizes a subset of the AWS SDK actions for Amazon GameLift. You can make calls from the AWS CLI or from your game client. All API actions perform locally just as they do in the Amazon GameLift web service.

Set Up Amazon GameLift Local

Amazon GameLift Local is provided as an executable .jar file bundled with the Server SDK. It can be run on Windows or Linux and used with any Amazon GameLift-supported language.

Before running Local, you must also have the following installed.

  • A build of the Amazon GameLift Server SDK version 3.1.5 or higher

  • Java 8

Test a Game Server

If you want to test your game server only, you can use the AWS CLI to simulate game client calls to the Amazon GameLift Local service. This verifies that your game server is performing as expected with the following:

  • The game server launches properly and initializes the Amazon GameLift Server SDK.

  • As part of the launch process, the game server notifies Amazon GameLift that the server is ready to host game sessions.

  • The game server sends health status to Amazon GameLift every minute while running.

  • The game server responds to requests to start a new game session.

  1. Start Amazon GameLift Local.

    Open a command prompt window, navigate to the directory containing the file GameLiftLocal.jar and run it. By default, Local listens for requests from game clients on port 8080. To specify a different port number, use the -p parameter, as shown in the following example:

    java -jar GameLiftLocal-3.1.6.jar -p 9080

    Once Local starts, you see logs indicating that two local servers were started, one listening for your game server and one listening for your game client or the AWS CLI. Logs continue to report activity on the two local servers, including communication to and from your game components.

  2. Start your game server.

    Start your Amazon GameLift-integrated game server locally. You don't need to change the endpoint for the game server.

    In the Local command prompt window, log messages indicate that your game server has connected to the Amazon GameLift Local service. This means that your game server successfully initialized the Amazon GameLift Server SDK (with InitSDK()). It has called ProcessReady() with the log paths shown and, if successful, is ready to host a game session. While the game server is running, Amazon GameLift logs each health status report from the game server. The following log messaging example shows a successfully integrated game server:

    16:50:53,217 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - SDK connected: /127.0.0.1:64247 16:50:53,217 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - SDK pid is 17040, sdkVersion is 3.1.5 and sdkLanguage is CSharp 16:50:53,217 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - NOTE: Only SDK versions 3.1.5 and above are supported in GameLiftLocal! 16:50:53,451 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - onProcessReady received from: /127.0.0.1:64247 and ackRequest requested? true 16:50:53,543 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - onProcessReady data: logPathsToUpload: "C:\\game\\logs" logPathsToUpload: "C:\\game\\error" port: 1935 16:50:53,544 INFO || - [HostProcessManager] nioEventLoopGroup-3-1 - Registered new process true, true, 16:50:53,558 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - onReportHealth received from /127.0.0.1:64247 with health status: healthy

    Potential error and warning messages include the following:

    • Error: “ProcessReady did not find a process with pID: <process ID>! Was InitSDK() invoked?”

    • Warning: “Process state already exists for process with pID: <process ID>! Is ProcessReady(...) invoked more than once?”

  3. Start the AWS CLI.

    Once your game server successfully calls ProcessReady(), you can start making client calls. Open another command prompt window and start the AWS CLI tool. If you haven't already set it up, see Install the AWS CLI. The AWS CLI by default uses the Amazon GameLift web service endpoint. You must override this with the Local endpoint in every request using the --endpoint-url parameter, as shown in the following example request.

    aws gamelift describe-game-sessions --endpoint-url http://localhost:9080 --fleet-id fleet-123

    In the AWS CLI command prompt window, calls to AWS SDK APIs result in responses as documented in the .

  4. Create a game session.

    With the AWS CLI, submit a CreateGameSession() request. The request should follow the expected syntax. For Local, the FleetId parameter can be set to any valid string (^fleet-\S+).

    aws gamelift create-game-session --endpoint-url http://localhost:9080 --maximum-player-session-count 2 --fleet-id fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d

    In the Local command prompt window, log messages indicate that Amazon GameLift Local has sent your game server an onStartGameSession callback. If a game session is successfully created, your game server responds by invoking ActivateGameSession.

    13:57:36,129 INFO || - [SDKInvokerImpl] Thread-2 - Finished sending event to game server to start a game session: arn:aws:gamelift:local::gamesession/fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d/gsess-ab423a4b-b827-4765-aea2-54b3fa0818b6. Waiting for ack response.13:57:36,143 INFO || - [SDKInvokerImpl] Thread-2 - Received ack response: true13:57:36,144 INFO || - [CreateGameSessionDispatcher] Thread-2 - GameSession with id: arn:aws:gamelift:local::gamesession/fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d/gsess-ab423a4b-b827-4765-aea2-54b3fa0818b6 created13:57:36,227 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - onGameSessionActivate received from: /127.0.0.1:60020 and ackRequest requested? true13:57:36,230 INFO || - [SDKListenerImpl] nioEventLoopGroup-3-1 - onGameSessionActivate data: gameSessionId: "arn:aws:gamelift:local::gamesession/fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d/gsess-abcdef12-3456-7890-abcd-ef1234567890"

    In the AWS CLI window, Amazon GameLift responds with a game session object including a game session ID. Notice that the new game session's status is Activating. Th3 status changes to Active once your game server invokes ActivateGameSession. If you want to see the changed status , use the AWS CLI to call DescribeGameSessions().

    { "GameSession": { "Status": "ACTIVATING", "MaximumPlayerSessionCount": 2, "FleetId": "fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d", "GameSessionId": "arn:aws:gamelift:local::gamesession/fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d/gsess-abcdef12-3456-7890-abcd-ef1234567890", "IpAddress": "127.0.0.1", "Port": 1935 } }

Test a Game Server and Client

To check your full game integration, including connecting players to games, you can run both your game server and client locally. This allows you to test programmatic calls from your game client to the Amazon GameLift Local. You can verify the following actions:

  • The game client is successfully making AWS SDK requests to the Amazon GameLift Local service, including to create game sessions, retrieve information on existing game sessions, and create player sessions.

  • The game server is correctly validating players when they try to join a game session. For validated players, the game server may retrieve player data (if implemented).

  • The game server reports a dropped connection when a player leaves the game.

  • The game server reports ending a game session.

  1. Start Amazon GameLift Local.

    Open a command prompt window, navigate to the directory containing the file GameLiftLocal.jar and run it. By default, Local listens for requests from game clients on port 8080. To specify a different port number, use the -p parameter, as shown in the following example.

    ./gamelift-local -p 9080

    Once Local starts, you see logs showing that two local servers were started, one listening for your game server and one listening for your game client or the AWS CLI.

  2. Start your game server.

    Start your Amazon GameLift-integrated game server locally. See Test a Game Server for more detail on message logs.

  3. Configure your game client for Local and start it.

    To use your game client with the Amazon GameLift Local service, you must make the following changes to your game client's setup, as described in Set Up Amazon GameLift on a Client or Service:

    • Change the ClientConfiguration object to point to your Local endpoint, such as http://localhost:9080.

    • Set a target fleet ID value. For Local, you do not need a real fleet ID; set the target fleet to any valid string (^fleet-\S+), such as fleet-1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d.

    • Set AWS credentials. For Local, you do not need real AWS credentials; you can set the access key and secret key to any string.

    In the Local command prompt window, once you start the game client, log messages should indicate that it has initialized the GameLiftClient and is successfully communicated with the Amazon GameLift service.

  4. Test game client calls to the Amazon GameLift service.

    Verify that your game client is successfully making any or all of the following API calls:

    In the Local command prompt window, only calls to CreateGameSession() result in log messages. Log messages show when Amazon GameLift Local prompts your game server to start a game session (onStartGameSession callback) and gets a successful ActivateGameSession when your game server invokes it. In the AWS CLI window, all API calls result in responses or error messages as documented.

  5. Verify that your game server is validating new player connections.

    After creating a game session and a player session, establish a direct connection to the game session.

    In the Local command prompt window, log messages should show that the game server has sent an AcceptPlayerSession() request to validate the new player connection. If you use the AWS CLI to call DescribePlayerSessions(), the player session status should change from Reserved to Active.

  6. Verify that your game server is reporting game and player status to the Amazon GameLift service.

    For Amazon GameLift to manage player demand and correctly report metrics, your game server must report various statuses back to Amazon GameLift. Verify that Local is logging events related to following actions. You may also want to use the AWS CLI to track status changes.

    • Player disconnects from a game session – Amazon GameLift Local log messages should show that your game server calls RemovePlayerSession(). An AWS CLI call to DescribePlayerSessions() should reflect a status change from Active to Completed. You might also call DescribeGameSessions() to check that the game session's current player count decreases by one.

    • Game session ends – Amazon GameLift Local log messages should show that your game server calls TerminateGameSession(). An AWS CLI call to DescribeGameSessions() should reflect a status change from Active to Terminated (or Terminating).

    • Server process is terminated – Amazon GameLift Local log messages should show that your game server calls ProcessEnding().

Variations with Local

When using Amazon GameLift Local, keep in mind the following:

  • Unlike the Amazon GameLift web service, Local does not track a server's health status and initiate the onProcessTerminate callback. Local simply stops logging health reports for the game server.

  • For calls to the AWS SDK, fleet IDs are not validated, and can be any string value that meets the parameter requirements (^fleet-\S+).

  • Game session IDs created with Local have a different structure. They include the string local, as shown here:

    arn:aws:gamelift:local::gamesession/fleet-123/gsess-56961f8e-db9c-4173-97e7-270b82f0daa6