i am working on an app that has the following:
frontend: html, js, and angular
middle tier: java restful service that simply converts data into JSON
backend: SAS service that the restful service methods call
i am trying to improve performance. i tried moving most of the processing/business logics from the frontend to the java restful service layer, but didn't see any major improvement. another area of concern is that the DB is not located in the same location as the SAS service, which in turn is not co-located with the restful service layer. so i see a lot of network latency and firewall issues that could be addressed. also, i am wondering if it wouldn't be better to replace the SAS service with a JPA framework, with entity classes and DAO classes underneath the restful service. what about using JDBC template to make direct calls to the DB, will scalability be an issue? thanks.