Cloud computing supplies IT resources through layers of abstraction instead of exposing the underlying infrastructure directly. Resources such as virtual machines, networks, storage, applications, and services are available on demand, provisioned quickly, and billed according to use. section 1.0
Cloud environments are characterized by:
- On-demand self-service through a console or API. section 1.0
- Broad network access and shared resource pools across multiple consumers. section 1.0
- Rapid elasticity, allowing capacity to expand or shrink as demand changes. section 1.0
- Measured service, providing usage metrics for operational and billing insight. section 1.0
Amazon Web Services provides a platform of cooperating services across infrastructure, platform, and software layers. Users can manage computing, storage, and networking through the web interface, command-line tools, SDKs, or infrastructure blueprints. Pay-per-use pricing makes capacity flexible, but usage must be monitored with budget alerts. section 1.10
A web shop on AWS
A web shop can move from a web server and database in a data center to virtual machines, a managed database, object storage, DNS, a content delivery network, and a load balancer. Separating static content from dynamic content improves performance; distributing the application across multiple virtual machines improves reliability when one instance fails; managed services reduce maintenance work. section 1.2.1
Figure 1.3 Running a web shop on AWS with CDN for better performance, a load balancer for high availability, and a managed database to decrease maintenance costs
Compare the basic on-premises arrangement with an AWS design using a CDN, load balancer, and managed database. section 1.2.1
