Three-Tiered Design

Learn how to implement middleware into the mod_perl/Apache design mix.

This month, we looked at the reasons behind three-tiered architectures and started to look into a basic implementation of an application that uses this architecture. As you can see, we can already create small text-mode applications. Next month, we will complete our implementation, giving us the skeleton for a simple appointment book using mod_perl/Mason and PostgreSQL. We will also discuss issues regarding the scalability of three-tier solutions, as well as some of the pitfalls.


Reuven M. Lerner owns and manages a small consulting firm specializing in Web and Internet technologies. As you read this, he should (finally!) be finishing Core Perl, to be published by Prentice-Hall later this year. You can reach him at, or at the ATF home page,