Request Syntax Request Parameters Response Syntax Response Elements Errors Examples See Also

StartGameSessionPlacement

This API works with the following fleet types: EC2, Anywhere, Container

Makes a request to start a new game session using a game session queue. When processing a placement request, Amazon GameLift Servers looks for the best possible available resource to host the game session, based on how the queue is configured to prioritize factors such as resource cost, latency, and location. After selecting an available resource, Amazon GameLift Servers prompts the resource to start a game session. A placement request can include a list of players to create a set of player sessions. The request can also include information to pass to the new game session, such as to specify a game map or other options.

Request options

Use this operation to make the following types of requests.

Request a placement using the queue's default prioritization process (see the default prioritization described in PriorityConfiguration). Include these required parameters:
- GameSessionQueueName
- MaximumPlayerSessionCount
- PlacementID
Request a placement and prioritize based on latency. Include these parameters:
- Required parameters GameSessionQueueName, MaximumPlayerSessionCount, PlacementID.
- PlayerLatencies. Include a set of latency values for destinations in the queue. When a request includes latency data, Amazon GameLift Servers automatically reorder the queue's locations priority list based on lowest available latency values. If a request includes latency data for multiple players, Amazon GameLift Servers calculates each location's average latency for all players and reorders to find the lowest latency across all players. To obtain accurate latency measurements, use Amazon GameLift Servers's UDP ping beacons. These endpoints allow you to measure actual UDP network latency between player devices and potential hosting locations, resulting in more accurate placement decisions than using ICMP pings. For more information on using UDP ping beacons to measure latency, refer to UDP ping beacons in the Amazon GameLift Servers Developer Guide.
- Don't include PriorityConfigurationOverride.
- Prioritize based on a custom list of locations. If you're using a queue that's configured to prioritize location first (see PriorityConfiguration for game session queues), you can optionally use the PriorityConfigurationOverride parameter to substitute a different location priority list for this placement request. Amazon GameLift Servers searches each location on the priority override list to find an available hosting resource for the new game session. Specify a fallback strategy to use in the event that Amazon GameLift Servers fails to place the game session in any of the locations on the override list.
Request a placement and prioritized based on a custom list of locations.
You can request new player sessions for a group of players. Include the DesiredPlayerSessions parameter and include at minimum a unique player ID for each. You can also include player-specific data to pass to the new game session.

Result

If successful, this operation generates a new game session placement request and adds it to the game session queue for processing. You can track the status of individual placement requests by calling DescribeGameSessionPlacement or by monitoring queue notifications. When the request status is FULFILLED, a new game session has started and the placement request is updated with connection information for the game session (IP address and port). If the request included player session data, Amazon GameLift Servers creates a player session for each player ID in the request.

The request results in a InvalidRequestException in the following situations:

If the request includes both PlayerLatencies and PriorityConfigurationOverride parameters.
If the request includes the PriorityConfigurationOverride parameter and specifies a queue that doesn't prioritize locations.

Amazon GameLift Servers continues to retry each placement request until it reaches the queue's timeout setting. If a request times out, you can resubmit the request to the same queue or try a different queue.

Request Syntax


{
   "DesiredPlayerSessions": [ 
      { 
         "PlayerData": "string",
         "PlayerId": "string"
      }
   ],
   "GameProperties": [ 
      { 
         "Key": "string",
         "Value": "string"
      }
   ],
   "GameSessionData": "string",
   "GameSessionName": "string",
   "GameSessionQueueName": "string",
   "MaximumPlayerSessionCount": number,
   "PlacementId": "string",
   "PlayerLatencies": [ 
      { 
         "LatencyInMilliseconds": number,
         "PlayerId": "string",
         "RegionIdentifier": "string"
      }
   ],
   "PriorityConfigurationOverride": { 
      "LocationOrder": [ "string" ],
      "PlacementFallbackStrategy": "string"
   }
}

Request Parameters

For information about the parameters that are common to all actions, see Common Parameters.

The request accepts the following data in JSON format.

Note

In the following list, the required parameters are described first.

GameSessionQueueName

Name of the queue to use to place the new game session. You can use either the queue name or ARN value.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 256.

Pattern: [a-zA-Z0-9-]+|^arn:.*:gamesessionqueue\/[a-zA-Z0-9-]+

Required: Yes

MaximumPlayerSessionCount

The maximum number of players that can be connected simultaneously to the game session.

Type: Integer

Valid Range: Minimum value of 0.

Required: Yes

PlacementId

A unique identifier to assign to the new game session placement. This value is developer-defined. The value must be unique across all Regions and cannot be reused.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 48.

Pattern: [a-zA-Z0-9-]+

Required: Yes

DesiredPlayerSessions

Set of information on each player to create a player session for.

Type: Array of DesiredPlayerSession objects

Required: No

GameProperties

A set of key-value pairs that can store custom data in a game session. For example: {"Key": "difficulty", "Value": "novice"}.

Note

Avoid using periods (".") in property keys if you plan to search for game sessions by properties. Property keys containing periods cannot be searched and will be filtered out from search results due to search index limitations.
If you use SearchGameSessions API, there is a limit of 500 game property keys across all game sessions and all fleets per region. If the limit is exceeded, there will potentially be game session entries missing from SearchGameSessions API results.

Type: Array of GameProperty objects

Array Members: Maximum number of 16 items.

Required: No

GameSessionData

A set of custom game session properties, formatted as a single string value. This data is passed to a game server process with a request to start a new game session. For more information, see Start a game session.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 262144.

Required: No

GameSessionName

A descriptive label that is associated with a game session. Session names do not need to be unique.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 1024.

Required: No

PlayerLatencies

A set of values, expressed in milliseconds, that indicates the amount of latency that a player experiences when connected to a fleet location (AWS Regions or custom locations for Amazon GameLift Servers Anywhere fleets). This information is used to try to place the new game session where it can offer the best possible gameplay experience for the players. To obtain accurate latency measurements, use Amazon GameLift Servers's UDP ping beacons. These endpoints allow you to measure actual UDP network latency between player devices and potential hosting locations, resulting in more accurate placement decisions than using ICMP pings. For more information on using UDP ping beacons to measure latency, refer to UDP ping beacons in the Amazon GameLift Servers Developer Guide.

Type: Array of PlayerLatency objects

Required: No

PriorityConfigurationOverride

A prioritized list of locations to use for the game session placement and instructions on how to use it. This list overrides a queue's prioritized location list for this game session placement request only. You can include AWS Regions, local zones, and custom locations (for Anywhere fleets). You can choose to limit placements to locations on the override list only, or you can prioritize locations on the override list first and then fall back to the queue's other locations if needed. Choose a fallback strategy to use in the event that Amazon GameLift Servers fails to place a game session in any of the locations on the priority override list.

Type: PriorityConfigurationOverride object

Required: No

Response Syntax


{
   "GameSessionPlacement": { 
      "DnsName": "string",
      "EndTime": number,
      "GameProperties": [ 
         { 
            "Key": "string",
            "Value": "string"
         }
      ],
      "GameSessionArn": "string",
      "GameSessionData": "string",
      "GameSessionId": "string",
      "GameSessionName": "string",
      "GameSessionQueueName": "string",
      "GameSessionRegion": "string",
      "IpAddress": "string",
      "MatchmakerData": "string",
      "MaximumPlayerSessionCount": number,
      "PlacedPlayerSessions": [ 
         { 
            "PlayerId": "string",
            "PlayerSessionId": "string"
         }
      ],
      "PlacementId": "string",
      "PlayerGatewayStatus": "string",
      "PlayerLatencies": [ 
         { 
            "