We have been running a 3 instances Keycloak cluster on AWS EC2 with some modifications on the standalone-ha.xml file that comes with official Keycloak distribution. The instance type we are using is fairly large (c5.4xlarge) and the whole system is fairly stable.
Recently, our company has moved to using AWS Fargate, which means we will have much less powerful machines. During our load testing, we are now running 18 instances of Keycloak and we are seeing a small amount of errors. Some requests are taking a really long time to complete. CPU and network usage also become very unstable, even after the load testing is done.
Does anyone have any suggestions on areas of interest where we can look into to eliminate the issues? Or it would be really helpful too if anyone can point us to some information on how to configure/run a large Keycloak cluster.
Much appreciated in advanced!