Introduction to Cloud Computing

Cloud Overview

• Cloud computing is the delivery of computing as a service over a network, whereby distributed resources are provided to the end user as a utility.
• The idea of utility computing originated in the 1950s and 1960s, but the enabling technologies evolved decades later and have finally matured to a state in which cloud computing is a viable option for organizations to invest in.
• The enabling technologies of cloud computing are networks, virtualization and resource management, utility computing, programming models, parallel distributed computing, and storage technologies.
• Cloud computing consists of four building blocks: application software, development platforms, resource sharing, and infrastructure.
• Cloud service models exist at various levels in the building blocks.
• Software as a service (SaaS) is at the application software layer and is the delivery of SaaS over the Internet (typically through a Web browser).
• Platform as a service (PaaS) is at the development platform layer and can be defined as a computing platform that allows for the creation of Web applications in a simplified manner without the complexity of purchasing and maintaining any of the underlying software and infrastructure.
• In the Infrastructure as a service (IaaS) model, providers rent out compute resources in the form of instances or virtual machines, which have some form of CPU, memory, disk, and network bandwidth attached to them.
• There are three well-known deployment models for cloud computing: public, private, and hybrid.
• Popular cloud providers include Amazon Web Services, Microsoft Azure, Google Cloud Platform and OpenStack. Each provider typically offers a stack consisting of compute, storage and networking services, among others.
• Some of the most popular use cases for the cloud include: web and mobile applications, big data analytics, on-demand high performance computing, online storage and archival, and rapid application development and testing.

Benefits, Risks, and Challenges of Cloud Computing

Benefits of the Cloud

• Economic model - pay as you go model, which is better than having to pay upfront, especially for startups.
• Simplified IT management
• Scalability
• Flexibility - able to configure any software platform to run on any available operating system as a virtualized image on custom-provisioned, rented infra.