Platform as a Service | PaaS
PaaS cloud computing platform is a developer programming platform which is created for the programmer to develop, test, run and manage the applications.
A developer is able to write the application as well as deploy it directly into this layer easily.
PaaS extend and abstract the IaaS layer by removing the hassle of managing the individual virtual machine.
In PaaS cloud computing platform, back end scalability is handled by the cloud service provider and the end user does not have to worry about to manage the infrastructure.
All the infrastructure to run the applications will be over the internet.
Advantages of PaaS cloud computing layer
1) Simplified Development
Developers can focus on development and innovation without worrying about the infrastructure.
2) Lower risk
No requirements of up-front investment in hardware and software. Developers only need a PC and an internet connection to start building applications.
3) Prebuilt business functionality
Some PaaS vendors also provide already defined business functionality so that users can avoid building everything from very scratch and hence can directly start the projects only.
4) Instant community
PaaS vendors frequently provides online communities where developer can get the ideas, share experiences and seek advice from others.
5) Scalability
Applications deployed can scale from one to thousands of users without any changes to the applications.
Disadvantages of PaaS cloud computing layer
1) Vendor lock-in
One have to write the applications according to the platform provided by PaaS vendor so migration of an application to another PaaS vendor would be a problem.
2) Data Privacy
Corporate data, whether it can be critical or not, will be private so if it is not located within the walls of the company there can be a risk in terms of privacy of data.
3) Integration with the rest of the systems applications
It may happen that some applications are local and some are in cloud. So there will be chances of increased complexity when we want to use data which in the cloud with the local data.
Top vendors who are providing PaaS cloud computing platform
Google Apps Engine (GAE)
SalesFroce.com
Windows Azure
AppFog
Openshift
Cloud Foundary from VMware
