Cloud: Platform-as-a-Service

Platform-as-a-Service

The runtime environment for applications is given by PaaS. It also provides the requisite development & deployment tools to build applications. Another feature that stands out in PaaS, which, makes the development of web applications a less cumbersome affair for those who do not have a development background, is the availability of a Point and click tool.

SalesForce.com, Google’s App Engine, are examples of suppliers providing PaaS. Developers can log into their websites and use the built-in API to develop web applications.

One of the drawbacks of using PaaS is that a specific supplier is locked-in by the developer. For example, using Google’s App Engine and writing an application in Python against Google’s API, for instance, is likely to only run in that context. Therefore the most significant issue in PaaS is the vendor lock-in.

The PaaS ecosystem depicts the interaction between developers and the PaaS API, along with its bundled development tools. The diagrammatic representation below also portrays end-user interaction with business-relevant applications.

Advantages

Below are the advantages of the PaaS model:

Lower Administrative Expenses

Consumers don’t have to think much about management because it’s the responsibility of the cloud provider.

Lower TCO (Total Cost of Ownership)

There is no need for customers to buy costly computers, servers, electricity, and data storage.

Scalable solutions

Based on application resource demands, it is effortless to scale up or down automatically.

Current Software Systems

The management of software versions and patch installs is the responsibility of the cloud provider.

Issues

Like SaaS, to maintain stable and safe connections to the supplier networks, PaaS often puts significant burdens on user browsers. PaaS shares many of SaaS’s problems, therefore. However, as seen in the following diagram, there are some fundamental issues associated with PaaS:

Portability Challenges between PaaS Clouds

While standard languages are used, platform service implementations can differ. For instance, due to proprietary methodologies of handling files, queue, or hash table interfaces which are different from other PaaS provider solutions, transitioning from one service provider to another can turn out to be a cumbersome and expensive affair.

Processor event Scheduling

The PaaS applications are event-oriented, which imposes resource constraints on applications, i.e. they must respond to a request within a specified time period.

PaaS applications security

Because PaaS applications are network-based, cryptography and security exposure management must be used explicitly by PaaS applications.

Features

Here are the features of the service model for PaaS:

• PaaS offers an environment for browser-based development. This helps the developer to create a database and edit the application code using either the programming interface of the application or the point-and-click tools.
• PaaS offers stability, scalability, and web service interfaces that are built-in.
• PaaS offers built-in tools for defining processes for workflow and approval and defining business rules.
• Integration with other applications on the same platform is simple.
• PaaS also provides interfaces for web services that allow us to communicate outside the platform applications.

Types of PaaS

PaaS can be divided into four groups based on functions, as shown in the following diagram:

Development Environments

For a particular function, the Stand-alone PaaS acts as an independent entity. Licensing, technological dependencies and particular SaaS implementations are omitted.

Only application delivery environments

On-demand scaling and device protection are included in the Application Delivery PaaS.

Open Service Platform

Open PaaS provides software that is open source and allows a PaaS provider to run applications.

Add-on development

The PaaS Add-on allows existing ones to be personalized.