- The Emergence of Web Applications
- Basic Definitions
- The Nature of the Web and Its Challenges
- Performance and Scalability
- The Internet Medium
- Wide Audience
- Always On
- Lack of Complete Control
- Measuring Performance and Scalability
- Measuring Performance
- Beyond Benchmarking
- Measuring Scalability
- Throughput and Price/Performance
- Scalability and Performance Hints
- Think End-to-End
- Scalability Doesn't Equal Performance
The Internet Medium
Six attributes of the Internet as a medium compound the challenge of delivering performance and scalability. The better we understand and appreciate these attributes, the more strategic we can be in meeting the challenge to build Web applications that perform and scale well.
First, as mentioned earlier, there is potentially a wide audience for Web application providers to managewider than in any other medium. Second, the Web is an interactive medium: Consumers not only receive information, they also submit it. Third, the Internet is dynamic in the sense that a given user request does not always result in the same server-side response. Fourth, the Internet as a utility is always on and providers have no guarantees about when and how often their information will be accessed. Fifth, providing information over the Internet is an integrated process that often depends on the coordination of multiple provider subsystems to deliver information. And sixth, providers lack complete control in terms of the delivery of information to consumers: There are many networking elements that exist between provider and consumer, most of which are not controlled by the provider.
Some of these attributes may seem obvious; some may not. In either case, thinking about the details and their implications will prepare you for the solutions part of this book.