Introducing scalability

Most e-businesses face the same challenges, the most significant of which are unpredictable growth and the ability to have solutions ready for unknown problems. If your Web site is typical, it most likely started with displaying company information and has evolved to processing simple, if not, complex transactions. You know now that the skills required to display information are different from those required to process transactions. Failure to optimize graphics, frequent table scans and joins of multiple tables, and the resulting I/O bottlenecks combine to degrade performance. Site availability is stressed by unpredictable traffic and inadequate discipline regarding systems management. The problems you're facing may be compounded by poor application design and systems that are poorly configured, under powered, or both.




Meeting such challenges requires unprecedented flexibility and capacity for change in all areas, especially your IT operation. We believe the success of future e-businesses may be tied to the selection of components that can be individually and/or collectively adjusted to meet variable demands. Such flexibility is called scalability and is a feature your team needs to understand and measure for each component within your infrastructure. Scalability is related to the features of performance (response time) and capacity (operations per unit of time) but should not be considered synonymous.

Scaling a multi-tiered infrastructure from end to end means managing the performance and capacities of each component within each tier. The basic objectives of scaling a component/system are to:

Increase the capacity or speed of the component.
Improve the efficiency of the component/system.
Shift or reduce the load on the component.
As one increases the scalability of one component, the result may change the dynamics of the site service, thereby moving the "hot spot" or bottleneck to another component. The scalability of the infrastructure depends on the ability of each component to scale to meet increasing demands.