[EschatonCometh]

You can upgrade instantly on AWS, it doesn't take weeks. A lot of problems with AWS Elasticsearch Service are caused by corporations trying to squeeze a dollar out of a dime.

T2 and T3s with no Master Nodes, let alone three, leads to a lot of problems.

When everything lives in MMAP'd memory and you are nickel and dime'n it with 4GB and one CPU. You're going to have a bad day.

[DanielVZ]

Yeah that was for sure not the case for 3 m5.large master nodes and several r4.2xlarge nodes.

The update was instant, what wasn't instant was the wait for the update. IDK if it was the maintenance window (which was set up for a weekend) or some bug, but we DID end up waiting weeks until it randomly updated.