The burgeoning number of visits to the Excite Web site has driven the company to reinforce the design of the site's infrastructure to include higher levels of redundancy, load-balancing, additional connectivity, and higher switching capacity to make sure that each visitor's experience remains consistently rewarding. Our money is made by people visiting the site, so every second that we're down is a loss of revenue to us. But we don't have the luxury of scheduling a 'maintenance window' as we once did in the days of the traditional data center. The company must instead rely on a redundant and well-oiled infrastructure to keep the site available at all times. Because of the 24-hour nature of the business, Minarik says he favors building as much redundancy into his topology as possible.
Load balancing is the only way to scale and manage server access.
If one server is not functioning or is occupied with other user requests, LocalDirector will route the call to an available server. If a server crashes, it is imperative that the network automatically adjust to route around the failure. Having to reconfigure the network for an outage or each time the server farm grows would not provide the automatic, real-time access required by a dynamic commerce environment. In addition, the LocalDirector devices themselves are redundant in the Excite implementation. They are directly attached to each other and continually exchange statistics so that one device can pick up the load of the other in the event that one goes out of commission.