Platform as a Service (PaaS) refers to the service in the cloud computing platform for the developers of Web applications widely known as Software as a Service (SaaS). This can include both the rapidly deployable runtime environments, typically needed for Web applications and also the development environment; which with minimal administrative effort and without the need to buy the underlying costly hardware and software can be used at as per need. Platform as a Service (PaaS) supports the entire software life cycle from design, development, testing, delivery to the effective operation of Web applications over the Internet. Platform as a Service a part of is Everything as a Service (XaaS).
Some Platform as a Service (PaaS) providers offer services like team collaboration for monitoring the security and also the middleware services for data storage. Platform as a Service (PaaS) offerings are typically built on a scalable infrastructure ( IaaS ), where the memory and processing power can therefore scale up or down as per need.
Based on a Platform as a Service (PaaS) environment, software as a service (SaaS) is created (SaaS) and delivered.
Types of Platform as a Service (PaaS)
- Application PaaS (aPaaS) or stand-alone environments of Platform as a Service (PaaS) : aPaaS refers to a cloud environment for building and running business applications with a graphical user interface or through an application programming interface (API). Typical example is a Web application for managing application in the Google App Engine.
- Integration and Governance PaaS (iPaaS) : In contrast, iPaaS as a cloud environment for mediating harmony between heterogeneous, cloud-based applications through interoperability, integration and governance. An example would be Mule iON.
- Add-on development environments of Platform as a Service (PaaS) : Add-on development environments make it possible to adapt existing software as a service (SaaS) applications.
- Pure Application Delivery form of Platform as a Service (PaaS) : Some Platform as a Service (PaaS) offerings do not support the development, debugging or testing applications, but offer only the operation of applications in a scalable environment.
- Open Platform as a Service (PaaS) : In open PaaS offers the developers with no bounding.
Structure, Properties and Special Features of Platform as a Service (PaaS)
Runtime and development environment Platform as a Service (PaaS)
With the subdivision of Platform as a Service (PaaS) in development and execution environment to the developer is allowed to agree on a development environment such as Django to define, but to be flexible in the choice of the execution environment.
Programming Model of Platform as a Service (PaaS)
The programming model of Platform as a Service (PaaS) is comparable to enterprise applications; cluster of application servers with load balancing, since both must be scalable and fail-safe in this case. There must be asynchrony, otherwise, one can reach only a Hosting in a cloud environment, which will be without good scalability and reliability.
Development Model of Platform as a Service (PaaS)
The development model does not differ greatly from application model of Platform as a Service (PaaS). Applications are locally designed, developed, tested, packaged and finally transferred to the cloud platform. Many vendors such as Google App Engine, Windows Azure or Amazon’s Elastic Beanstalk allow to run multiple versions of the same application in parallel.
Run-time environment of Platform as a Service (PaaS)
The runtime environment of a Platform as a Service (PaaS) environment can be configured via a web interface or API. Thus, for example, applications are started and ended or the maximum and minimum number of instances can be determined. Also, the monitoring and related applications can be made by API or a Web interface.
Non Structural Functional Units of Platform as a Service (PaaS)
Non Structural Functional units of Platform as a Service (PaaS) includes :
- Persistence : Because many customers still require SQL databases for easy application migration to the cloud, now these are also offered as classically most Platform as a Service (PaaS) providers are not build on relational databases.
- Concurrency and communication : In order to guarantee the execution of asynchronous computations or to enable them all, most of Platform as a Service (PaaS) providers have a messaging infrastructure in the program.
- Access Layer : The most important is the role of the HTTP protocol, access to applications to a PaaS environment usually done via HTTP.
- Multi-client capability (multi-tenancy) : Here the client sessions are dependent or independent of each application instances. This has been added in Platform as a Service (PaaS) later for easier delivery.