06-09-2017, 12:34 PM
The three tier middleware architecture is commonly used to house distributed applications in the enterprise. Typically, the application decomposes into three layers: front-end, middle-tier, and back-end. Front-end ("Web Server") is responsible for managing user interactions and acts as a buffer layer client, while the back side facilitates storage for applications. The middle level ("application server") is the place where all calculations are performed. One of the benefits of this architecture is that it allows the flexible management of a group of computers for performance and scalability; In addition, measures of availability, such as replication, can be introduced at each level in an application-specific manner. However, incorporating the availability measures into a multi total system poses challenging system design problems for unattended solutions, unopened and non-proprietary switches, transparent switching, and the ability to work with clusters.