Three, or even more layer architectures aren't anything new. I used to work for a bank that was developing a multi layer application. It used the following layers:
  1. Reverse proxy, hiding the internal structure from the outside world.
  2. HTTP to HTTPs redirection.
  3. SSL accellerator.
  4. Reverse proxy on the corporate network/operations boundary.
  5. Level 4 load balancing switch.
  6. Siteminder URL access check.
  7. Apache/Tomcat front-end, portal to several applications. (This layer did the presentation).
  8. Websphere with *application* business logic (2 databases here: one for the application, one for websphere).
  9. "Common", set of Java classes and a database for *bank* business logic.
  10. Messages system, layer between the application database and SWIFT routers.
  11. SWIFT routers.
Now try solving a "500 error" in that mess.

Abigail

In reply to Re: Three-layer web application architecture by Abigail-II
in thread Three-layer web application architecture by pg

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