I have a VPC in AWS that contains a public and private subnet. In the private subnet, I have two load balanced EC2 app servers, and an EC2 Database/Cache server.
The two app servers connect to the Database/Cache server for database queries, but there is also an instance of Redis running on the database server. Both of the app servers are configured to connect to this redis instance.
My question is - is this performant? Would it be better to have an instance of Redis installed on each of the App server nodes?
Or are we better off leaving redis on the database/cache server?