a major online data service wants to provide better response and access times for its users and visitors. they plan on deploying thousands of mini-web servers to isps across the nation. these mini-servers will host the few dozen main pages of their website so that users will be routed to the logically and geographically closest server for optimal performance and minimal latency. only if a user requests data not on these mini-servers will they be connecting to the centralized main web cluster hosted at the company's headquarters. what is this type of deployment commonly known as?