[xeus2001]

We currently run a Java Monolith that is build on every push to master on Gitlab pipeline, when successful the fat JAR is copied to S3 (including all resources) and then a config file is pushed to S3 to ask DEV servers to run it. The machines are pure EC2 instances with the service registered in systemd with auto-restart after 5s. A simple shell script downloads the config file, the fat JAR and runs it. We detect the environment and machine we're at using the EC2 meta- and user-data, which is set when the EC2 instance is launched. All of this is basically simple plain batch script using JQ and other standard tools. It is a little more complicated, because we have graceful restart by first asking a specific instance in each cluster to update itself and when it reports that is is updated, the next instance will be asked to update. All the EC2 instances in a cluster are behind a simple Global Accelerator and are in multiple regions. The service has an API that is invoked by Gitlab with a token to ask for graceful restart, then it will report back to GA that it is unhealthy for some time, so it can finish pending requests (close sockets) and then it simply terminates, the rest is back up to bash script and systemd. To deploy or redeploy to an environment is as well a simply click in Gitlab UI and especially important for On-Call, so you can see which version was deployed to which environment when by whom. Additionally some JIRA tickets are automatically created. Eventually this only needs Gitlab, EC2 instances, Global Accelerator and Bash scripts, while allow us to be multi-region and have stateful connections, we can even ask clients to directly connect to specific instances or ask GA to redirect certain ports to specific instances. Basically GA is our load balancer, router, edge location. It is stable, fast and easy with the smallest amount of pieces involved. We can remove individual instances, update one instances in a specific region for testing to a new version and so on.