Implementation details

We describe the architectural design and the implementation of the one-way layer-7 Web switch based on the TCP Handoff approach, called ClubWeb-1w. The switch software has been conceived as an extension of the TCP/IP stack under the Linux operating system, kernel version 2.4.18. Particular care has been taken in avoiding slow and inefficient constructs, and in implementing thread-safe code. The implementation takes full advantages of the Linux multi-threaded TCP/IP stack and results particularly efficient on SMP nodes. The cluster operations are implemented through the following software modules: dispatcher, forwarder, THOP communication protocol, load monitor. We describe them by showing how they fulfill the design requirements in Section 2.2.