Selecting a Cloud Service
Cloud services are a relatively new type of service, and for those used to downloading and installing software, it may be daunting at first when trying to figure out which cloud service to use. Let’s analyze the different options.
Infrastructure as a Service
Infrastructure as a service (IaaS) is the provisioning of IT resources as a cloud service. The IT resources or infrastructure include virtual machines (VMs), dedicated hardware, data storage, databases, and networking. Load balancers and IP addresses are also included with IaaS.
The cloud service provider is responsible for provisioning the physical computing resources at data centers. The service user has to manage the infrastructure in terms of connecting to virtual machines, maintaining and patching the VM operating system, and installing and running needed software.
An example of when to choose IaaS would be if you want to use a cloud service-based VM running a Linux operating system to install and run some software.
Platform as a Service
With IaaS, a user has to manage the infrastructure. With platform as a service (PaaS) the infrastructure—hardware, operating system, networking, and storage—are managed by the cloud service itself. You have to be concerned only with deployment and management of applications.
The PaaS manages several aspects:
- Procuring the resources, such as VM operating system images
- Planning capacity
- Maintaining software such as databases
- Applying patches
- Applying software updates
PaaS may also include provisions to design, develop, test, and deploy applications, and other services such as web service integration, team collaboration, monitoring, and logging.
An example of when to choose PaaS would be if you want to use a cloud service to run some user-developed applications but don’t know much about maintaining operating systems, servers, networks, or databases.
Software as a Service
Software as a service (SaaS) is a managed service for some software. The software could be specific to an industry, such as automotive or communications, which is known as vertical SaaS. Or the software could be specific to a category, such as sales or databases, which is called horizontal SaaS.
Typically, SaaS is based on a multi-tenant architecture in which multiple subscribers or users share the same software and infrastructure (hardware, operating system, and network). SaaS typically allows a user to customize application configuration to some extent. Some SaaS services provide the option to select a software version from a list of available versions. With multiple users using the same software service, some SaaS providers also provide features for information-sharing and collaboration.
An example of when to choose SaaS is if you want to use a database but don’t know how to download, install, and configure the database. Database as a service (DBaaS) is also a type of SaaS.
Selecting a cloud service is dependent on how much input you’re able to provide to run the software or application that you want to run. If you know all about managing hardware, operating systems, networks, and software, the IaaS is the cloud service to choose. If you don’t know anything about infrastructure management and you’re only concerned about application deployment and management, choose PaaS. And to let the cloud service manage the application or software, select a SaaS.
