Summary

There are a growing number of options for boosting server performance and availability. Global load distribution and a tiered architecture provide high levels of availability with two levels of redundancy: multiple sites and multiple servers within each site.

Individual servers must be optimized as they are assigned to tiers. As transactions flow through the tiers, they can be load balanced by content switches or accelerated with new front-end processors.

Content delivery infrastructures speed the delivery of content, opening new opportunities for service providers and their customers. Providers have new, high-margin services to offer, while customers have new applications that save money, increase competitive advantage, and strengthen their Internet presence. The traditional use of a centralized origin server is being replaced by a set of content servers at the edge. That enables customers to get high-quality, content-rich services, while providers avoid moving large volumes of time-sensitive content across their backbones.

The distribution of servers across the network means that managing server instrumentation is becoming a critical skill. Load distribution, caching, and content distribution networks greatly affect both performance and the management information that is available to system administrators. (A lot of the end-user activity may be concealed from the original server's management tools if it comes out of cache or content-distribution networks instead of from the original server.)

These services also need to be managed to ensure that they provide a return on investment. Each type of service provides element-level management data, but synthetic transactions from many locations in the system are important for Service Level Agreements (SLAs) and for handling performance issues.