How did you go about stopping and restarting applications which reach out to the database? We have a number of tasks running in ECS which can take a minute to spin down and a few minutes to spin back up.
For our web service, we didn't stop anything. They had a few seconds of errors though it seems like some sessions were just buffered or paused and experienced high latency.
We also had background worker services. For the very high throughput ones, we spun down the # of tasks to a bare minimum for <5 minutes and let the queue build up, rather than have a massive amount of errors and retries. For the other ones where throughput wasn't high, we just let them be, and during the downtime they errored and retried and the retries mostly succeeded.
