|
To build Web sites for electronic commerce and other mission-critical applications administrators are mirroring site content at an additional point of presence. This provides redundancy in case one POP goes down, and enables traffic to be routed between the sites to increase response time. Global Dispatch uses the three most important factors in determining where to send a request: POP availability, POP load, and the Internet latency between the client and each POP.
As requests are received, the Global Dispatch scheduler instructs the agents at each Web server to measure the latency between the POP and the client's local DNS. Results are sent back to the Global Dispatch scheduler and combined with current load and availability information to return to the client the IP address (or virtual IP address) of the POP best suited to respond. Global Dispatch stores this information in cache to enable faster response to future requests.
Global Dispatch takes advantage of existing server resources, regardless of their location on an intranet or the World Wide Web. It can work in conjunction with existing LAN load-balancing solutions or Resonate Central Dispatch to further increase performance.