Use cases for IaaS

Like SaaS and PaaS, IaaS is best suited to certain scenarios. It is most suitable when enterprises want to have more control over their infrastructure. Some of the most common instances when an IaaS is used are as follows:

• Backups and snapshots
• Disaster recovery
• Web hosting
• Software development environments
• Data analytics

Examples of AWS IaaS services

These are a few of the IaaS services offered in AWS:

• Elastic Cloud Compute (EC2): One of the most popular services in AWS. EC2 is a fancy word for a server on the cloud.
• Elastic Block Storage (EBS): Amazon EBS is block-level storage. You can think of it as a SAN (Storage Area Network) drive on the cloud.
• Elastic File Storage (EFS): Amazon EFS is file-level storage. You can think of it as a NAS (Network Attached Storage) drive on the cloud.

There are many other AWS IaaS services that you will learn through this book. The next section will cover another common paradigm used in PaaS cloud deployments.

Understanding PaaS

Defining a SaaS service is easy. If AWS manages everything, it’s a SaaS service. The same applies to a definition of an on-premises service. If you manage everything on your infrastructure, it’s clear you have an on-premises service. As you start going up and down the stack and start taking over the management of some of the components or start offloading some of the management, the line starts getting fuzzy. We’ll still try to provide you with a definition for PaaS.An initial definition could be this: any application where you are responsible for the maintenance of some of the software and some of the configuration data. More formally, Platform as a Service (PaaS) is a type of cloud computing service that supplies an environment to enable its users to develop, run, and manage data and applications without worrying about the complexity associated with provisioning, configuring, and maintaining the infrastructure. These complexities come in the IaaS model, where you are responsible for creating applications, including the servers, storage, and networking equipment.In some ways, PaaS is like SaaS, but instead of providing services to end-users that do not need to be technically savvy to use the Software, PaaS delivers a platform for developers to potentially use the PaaS service to develop SaaS solutions.PaaS enables developers to design and create applications while operating at a very high level of abstraction and focusing primarily on business rules and user requirements. These applications, sometimes called middleware, can be highly scalable and available if developed appropriately. Let’s take an example of a PaaS service called Amazon RDS (Relational Database Service), where AWS provides managed relational databases such as Oracle, MS SQL, MYSQL, etc., in the cloud. AWS handles database engine installation, patching, backup, recovery, repair, etc. You need to build schema and store your data as per business needs. Like SaaS, PaaS takes advantage of virtualization technology. Resources can be started or shut down depending on demand. Additionally, AWS offers a wide selection of services to support PaaS applications’ design, development, testing, and deployment.Let’s now look into the advantages and disadvantages of PaaS. Some use cases for PaaS and some examples of services are considered PaaS services.