Discuss the capabilities that the cloud users can get through Platform-as-a-service (PaaS). Also, mention the key characteristics of PaaS.

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 Platform as a service (PaaS)

  • Platform as a service (PaaS) is a category of cloud computing services that provide a computing platform and a solution stack as a service. Along with software as a service (SaaS) and infrastructure as a service (IaaS), it is a service model of cloud computing. PaaS offerings facilitate the deployment of applications without the cost and complexity of buying and managing the underlying hardware and software and provisioning hosting capabilities.
  • Technically, a PaaS is an Application Platform comprised of an operating system, middleware, and other software that allows applications to run on the cloud with much of the management, security, scaling, and other stack-related headaches abstracted away. This allows you to focus on two things: customers and developing your application. Let the PaaS deal with system administration details like setting up servers or VMs, installing libraries or frameworks, configuring testing tools, etc.
  • Platform as a Service allows users to create software applications using tools supplied by the provider. PaaS services can consist of preconfigured features that customers can subscribe to; they can choose to include the features that meet their requirements while discarding those that do not. PaaS works on top of IaaS and will do all of that work automatically.


Characteristics of PaaS

1. Multi-tenant architecture

A PaaS offering must be multi-tenanted. A multi-tenant platform is one that uses common computing resources including hardware, operating system, software (i.e. application code), and a single underlying database with a shared schema to support multiple customers simultaneously.


2. Customizable /Programmable User Interface

PaaS offering should provide the ability to construct highly flexible user interfaces via a simple “drag & drop” methodology that permits the creation and configuration of UI components on the fly.

Furthermore, given the growing set of Web devices, additional flexibility to use other technologies such as CSS, AJAX, and Adobe Flex to specify the appearance of the application’s interface should be available to the UI designer.


3. Unlimited Database Customizations


The database used by the application should have the option of customization for more flexibility in application development. Specifying relationships between objects, a key requirement of any sophisticated business application, must be possible through the declarative Web-based interface. Other mandatory functions include the ability to incorporate validation rules and permissions at the object/field level and the ability to specify auditing behavior.


4. Automation

PaaS environments automate the process of deploying applications to infrastructure, configuring application components, provisioning and configuring supporting technology like load balancers and databases, and managing system change based on policies set by the user.


5. Security

The PaaS offering should provide a flexible access control system that allows detailed control over what users of the SaaS application can see and the data each user can access. Definition of access from the application level (including tabs, menus, objects, views, charts, reports and workflow actions) to the individual field level should be possible. Defining an access control model should be possible through the creation of groups and roles and the assignment of users to either groups or roles.

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