SNS calls from flexmatch are all out of order

I have an SNS notification topic subscribed to a lambda function. The SNS topic received notifications from a FlexMatch event which tells it what the matchmaking type is for a certain ticket id. The notification is sent when the type changes. But, they are all out of order. For example, searching for a new event is sent before canceled on a previous event. Or request accepting match is sent after match accepted.

Is there a fix to this issue, it’s not a huge deal yet, but with enough players, I imagine it would become an issue.


A standard SNS topic is by its very nature best-effort ordering. You could use a FIFO topic to control order better. See Amazon Simple Notification Service (SNS) Features | Messaging Service | AWS

There some more information about which messages and timestamps to aid with re-ordering here: How reliable is the time field in the FlexMatch event notification messages? - #2 by chrisgong

If you can provide a FlexMatch config/rule set + region and some sample ticket ids where you think you received events out of order, I can ask the GameLift service to take a look and see if they have any advice for you.


Sorry for the late response I wanted to read everything before getting back and I’ve been quite busy lately.

But, I went through the articles as well as googling things and it seems, at least for my case, the order shouldn’t be the biggest issue, but rather just managing timing should work. Just to test that I implemented a simple use case and it’s been working consistently. I am not sure if it is going to work as well on a larger scale, but the performance does seem promising, so I am just going to hope for the best.

Appreciate the help!