Summary

The application infrastructure is aptly named because most applications are composed of related elements and supporting services. Applications include customer-facing elements, which are activated most often through a browser, as well as backend functions, such as credit authorization and order tracking. A single interaction with an end user commonly involves multiple applications and services, and those applications and services are themselves usually constructed of many smaller modules. Delivering superior service quality in such a system requires good coordination and management of the supporting applications and services.

One essential need is for closer communication among application designers and the operations teamsbefore, during, and after deployment. Application performance is sensitive to many factors that designers usually ignore, such as transmission delay, the number of turns, or back-and-forth data exchanges needed for a transaction.

Legacy applications usually lack adequate instrumentation, whereas newer applications are providing some embedded monitoring and tracing functions. Instrumentation allows administrators to track application workload as well as business and customer behavior.