Platform-as-a-Service PaaS

Paas provides the capability to the end users to deploy their application onto a cloud infrastructure using programming languages and tools supported by the provider. PaaS is the layer of cloud technology which sits upon the cloud infrastructure (most PaaS provider leverage Infrastructure-as-a-service provided by existing players) and provides application level services which are required for an application to run. In theory, a user should be able to take their already running application and deploy them on a PaaS provider whose platform supports the technology stack used by their application (language, application server, databases etc). Because of the very nature of Cloud, the end user is not required to manage or control the underlying infrastructure including network, servers, load balancing, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations. Unlike the case of a traditional system, PaaS provides the basis for developers to create scalable applications. Applications for a public PaaS cloud can:

(1) Use the elasticity offered by the underlying infrastructure to deloy large quantities of computing resources (CPU, Storage, Memory etc) as needed,
(2) Be deployed nearly instantly,
(4) Relieve subscribers of numerous IT chores by using various external services like Performance monitoring and tuning, Aplication management, Application Debugging etc, and
(5) Be purchased incrementally, by paying ongoing usage fees instead of traditional up-front costs for equipment and IT staff training.

Who are the ideal users for PaaS?

Application developers, who design and implement an application's software. Application testers, who run applications in various (possibly cloud-based) testing environments. Application deployers, who publish completed (or updated) applications into the cloud. Application administrators, who configure, tune, and monitor application performance on a platform. Application end users, who subscribe to the applications deployed on a PaaS cloud.

What does a typical PaaS user get from the PaaS infrastructure?

PaaS provider normally provides thier users with the use of the PaaS cloud provider's tools and execution resources to develop, test, deploy and administer applications. PaaS provides a low-cost way of developing and deploying applications. A variety of toolkits exist for developing PaaS applications and supporting them both at the server side via data stores and server-side processing frameworks and at the client side via thin clients and especially browser-based processing frameworks.

How are the PaaS usage fees calculated?

PaaS fees are typically calculated based on the number of subscribers, the kind of subscribers (e.g., developers vs. application end users), storage, processing, or network resources consumed by the platform, requests serviced, and the time the platform is in use.

PaaS providers are able to manage the lower layers and relieve PaaS subscribers of the responsibility for selecting, installing, maintaining, or operating the platform components. Infrastructure charges are implicitly present in PaaS including charges for CPU, bandwidth, storage etc. PaaS shares many of the benefits of SaaS including
- Modest Software Tool Footprint
- Centralized Management and Data
- Platform Issues Managed by Providers, and
- Savings in Up-front Costs facilitated Scalable Application Development and Deployment

In addition, PaaS platform helps ISVs to de-risk their business by offering the following advantages.

Ubiquitous access: Its being internet driven, PaaS platform ensures access to resources from anywhere in the world. This is critically important to software companies whose development work is spread across geographies.
Eliminating upgrades: PaaS platform ensures that an ISV does not have to keep on investing in OS upgrades and maintenance.
Low capital expenditure: PaaS platform makes it easier for the software development companies to manage their working capital needs better as their revenues are largely project driven.
Predictable expenditure: As the resource utilization is controlled by the clients, operating expenses are more predictable. For instance, with PaaS platform, the outsourced software product development (OPD) companies can assign separate budgets for independent projects with ease.
Facilitates collaboration: PaaS platform allows for collaboration between organizations in neutral third-party land. For example, ISVs can co-develop an application leveraging a third party PaaS platform.
Fast implementation: Since PaaS platform does not entail local installation, the adoption speed is usually high.
Rapid scalability: An ISV can increase the resource utilization as and when required without any delay.

As PaaS landscape matures we are going to see bifurcation in terms of what PaaS really means to its users. There are PaaS vendors who are specifically targetting IT departments and developers. Their offerings are more application infrastructure oriented and include services like message queues, support for multiple data stores, access to scheduling services, background processes etc. At the same time another breed of vendors is emerging which is much more business user focussed. These providers, also known as APaaS or Application Platform as a Service providers, aim to provide a visual development environment which can be used by end business users to create, deploy, manage and monitor their small to medium complxity business apps without any support from their IT departments.
Whereas pure PaaS players (also referred to as IPaaS Infrastructure PaaS) are very language centric (PHP, Ruby, Python, Java etc), APaaS providers have their own proprietary Visual development environment and do not emphasise their underlying runtime infrastructure at all ...less