Motivation

Even after the initial implementation of FIFO message groups in #8238, users have reported odd behavior when using SQS FIFO queues related to message group visibility specifically that consumers are triggered although the message group is expected to be invisible #8724. This also affected lambdas triggered with fifo queues #7036.

This PR fixes the mechanism we were using to reset message group visibility, which was too general. It assumed that every message put into the message group reset its visibility, when really it should just be messages that were previously invisible, not new ones.

Changes

• message group visibility is no longer reset when new messages are sent to the queue

Fixes

• bug: Incorrect behavior of receive message in sqs fifo queue with same group ID #8724
• bug: Lambda should correctly process FIFO queue event sources #7036 (tested with Add integration test for SQS FIFO event source order/parallelism #7037)