messageGroupId property

String? messageGroupId
final

This parameter applies only to FIFO (first-in-first-out) queues.

The tag that specifies that a message belongs to a specific message group. Messages that belong to the same message group are processed in a FIFO manner (however, messages in different message groups might be processed out of order). To interleave multiple ordered streams within a single queue, use MessageGroupId values (for example, session data for multiple users). In this scenario, multiple consumers can process the queue, but the session data of each user is processed in a FIFO fashion.

  • You must associate a non-empty MessageGroupId with a message. If you don't provide a MessageGroupId, the action fails.
  • ReceiveMessage might return messages with multiple MessageGroupId values. For each MessageGroupId, the messages are sorted by time sent. The caller can't specify a MessageGroupId.
The length of MessageGroupId is 128 characters. Valid values: alphanumeric characters and punctuation (!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~).

For best practices of using MessageGroupId, see Using the MessageGroupId Property in the Amazon Simple Queue Service Developer Guide.

Implementation

final String? messageGroupId;