Article:
  Introducing mod_security
Subject:   Tracking stateful session information is important for Web application security firewall appliance
Date:   2004-12-18 16:00:19
From:   Meshfire
because some users may log in and stay online for a long time, and the stateful session data may accumulate to a large size. Also, I think Web application firewalls for LAMP (linux apache Perhl/PHP/Python) is also worth working on for security since many companies are use LAMP by Meshfire .