Hi Jean Paul,
Some months ago, we’ve migrated 2 of our dhis2 2.30 servers into Amazon. We’re using EC2 instances t2-large. These are not production servers, meaning we do not have lot of users connected at the same time, but so far everything is working properly. Our setup for these servers is very basic all the services and servers (tomcat, database, nginx,…) are running in the same hosting machine.
Looking at your users quantity, i will suggest, as a starting point, to create a separate instance for hosting your DB but this means to pay extra.
Then, as a tip, also take into account that the dhis2 2.30 implementation docs are explained using an Ubuntu server which is different to the OS image we’re using “Amazon Linux 2 AMI”.