Platform-as-a-service offers the run time environment for applications. It also offers development and deployment tools required to develop applications. Paas has a feature of point-and-click tools that enables non-developers to create web applications.
Google App Engine and Force.com are examples of Paas offering vendors. Developers may log on to these websites and use the built in API to create web-based applications.
Google App Engine and Force.com are examples of Paas offering vendors. Developers may log on to these websites and use the built in API to create web-based applications.
Paas types-
1) Application delivery only environments - The application delivery Paas includes on-demand scaling and application security.
2) Stand alone development environments - The stand alone Paas works as an independent entity for a specific function. It does not include licensing or technical dependencies on a specific Saas applications.
3) Open Platform as a Service - Open Paas offers an open source software that helps a Paas provider to run applications.
4) Add-on-development facilities - The add-on Paas allows to customize the existing Saas platform.
Characteristics-
- Paas provides built-in security, scalability and web service interface.
- Paas provides built-in tools for defining workflow, approval processes and business rules.
- Easy to integrate Paas with other applications on the same platform.
- Paas also provides web service interfaces that allow us to connect the application outside the platform.
Advantages -
- Lower administrative overhead - customer need not bother about the administration because it is the responsibility of cloud provider.
- Lower total cost of ownership - customer need not purchase expensive hardware, servers, power and data storage.
- Scalable solutions - It is very easy to scale the resources up or down automatically, based on their demand.
- More current system software - It is the responsibility of the cloud provider to maintain software versions and path installations.
Disadvantages -
- Event based processor scheduling - The paas applications are event oriented which poses resources constraints on application ie- they have to answer a request in a given interval of time.
- Security engineering of Paas application - Since Paas applications are dependent on network, they must explicitly use cryptography and manage security exposures.