In the AWS Certified Solutions Architect – Professional 2019 (Beta Exam), Chapter 6 – Architecting to Scale, in the SNS section, at approximately 0:32 seconds:
I believe the default TTL for SNS should be 4 weeks, not 4 days.
4 days is the default for SQS, not SNS.
Reference #1: https://aws.amazon.com/sns/faqs/
Q: What is the default TTL?
A: SNS uses a default Time to Live (TTL) of 4 weeks for all mobile platforms.
Reference #2: https://docs.aws.amazon.com/sns/latest/dg/sns-ttl.html – Reference "4. Amazon SNS default TTL (4 weeks)" under "Precedence Order for Determining TTL."
Thanks for calling this out. I’m coming up with some confusing information on this topic. Some resources seem to indicate that the TTL is more for SMS and Push to mobile and System-to-System messaging (HTTP, Lambda and SQS endpoints) seem to have different retry rules and retention durations. I’m still digging and will update when I find something conclusive.
On the up side, there wasn’t any questions around retention rules on my Beta exam…maybe because they are in flux.
UPDATE: After much research, there are many different TTLs depending on the endpoint. I edited the video to remove reference to a retention and noted that it is designed to be transient storage…just don’t plan on leaving data in SNS without acting on it.