AWS SDK Version 3 for .NET
API Reference

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Finds new players to fill open slots in currently running game sessions. The backfill match process is essentially identical to the process of forming new matches. Backfill requests use the same matchmaker that was used to make the original match, and they provide matchmaking data for all players currently in the game session. FlexMatch uses this information to select new players so that backfilled match continues to meet the original match requirements.

When using FlexMatch with GameLift managed hosting, you can request a backfill match from a client service by calling this operation with a GameSession identifier. You also have the option of making backfill requests directly from your game server. In response to a request, FlexMatch creates player sessions for the new players, updates the GameSession resource, and sends updated matchmaking data to the game server. You can request a backfill match at any point after a game session is started. Each game session can have only one active backfill request at a time; a subsequent request automatically replaces the earlier request.

When using FlexMatch as a standalone component, request a backfill match by calling this operation without a game session identifier. As with newly formed matches, matchmaking results are returned in a matchmaking event so that your game can update the game session that is being backfilled.

To request a backfill match, specify a unique ticket ID, the original matchmaking configuration, and matchmaking data for all current players in the game session being backfilled. Optionally, specify the GameSession ARN. If successful, a match backfill ticket is created and returned with status set to QUEUED. Track the status of backfill tickets using the same method for tracking tickets for new matches.

Only game sessions created by FlexMatch are supported for match backfill.

Learn more

Backfill existing games with FlexMatch

Matchmaking events (reference)

How GameLift FlexMatch works

Related actions

StartMatchmaking | DescribeMatchmaking | StopMatchmaking | AcceptMatch | StartMatchBackfill | All APIs by task


For .NET Core this operation is only available in asynchronous form. Please refer to StartMatchBackfillAsync.

Namespace: Amazon.GameLift
Assembly: AWSSDK.GameLift.dll
Version: 3.x.y.z


public abstract StartMatchBackfillResponse StartMatchBackfill(
         StartMatchBackfillRequest request
Type: Amazon.GameLift.Model.StartMatchBackfillRequest

Container for the necessary parameters to execute the StartMatchBackfill service method.

Return Value
The response from the StartMatchBackfill service method, as returned by GameLift.


InternalServiceException The service encountered an unrecoverable internal failure while processing the request. Clients can retry such requests immediately or after a waiting period.
InvalidRequestException One or more parameter values in the request are invalid. Correct the invalid parameter values before retrying.
NotFoundException A service resource associated with the request could not be found. Clients should not retry such requests.
UnsupportedRegionException The requested operation is not supported in the Region specified.

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

See Also