Platform as a service
Encyclopedia
Platform as a service (PaaS) is a category of cloud computing services that provide a computing platform and a solution stack
as a service. In the classic layered model of cloud computing, the PaaS layer lies between the SaaS
and the IaaS layers.
PaaS offerings facilitate the deployment of applications without the cost and complexity of buying and managing the underlying hardware and software and provisioning hosting capabilities, providing all of the facilities required to support the complete life cycle of building and delivering web application
s and services
entirely available from the Internet.
PaaS offerings may include facilities for application design, application development, testing, deployment and hosting as well as application services such as team collaboration, web service integration and marshalling
, database integration, security, scalability, storage, persistence, state management, application versioning, application instrumentation and developer community facilitation. These services may be provisioned as an integrated solution over the web
.
These facilities allow customization of existing software-as-a-service
(SaaS) applications, and in some ways are the equivalent of macro language customization facilities provided with packaged software applications such as Lotus Notes
, or Microsoft Word
. Often these require PaaS developers and their users to purchase subscriptions to the co-resident SaaS application.
Stand alone development environments
Stand-alone PaaS environments do not include technical, licensing or financial dependencies on specific SaaS applications or web services, and are intended to provide a generalized development environment.
Application delivery-only environments
Some PaaS offerings lack development, debugging and test capabilities, and provide only hosting-level services such as security and on-demand scalability.
Open platform as a service
Lets the developer use any programming language, any database, any operating system, any server, etc.
Different PaaS offerings provide different combinations of services to support the application development life-cycle. Comprehensive PaaS should provide all service options in an integrated development environment within the actual target delivery platform, with source code control, version control, dynamic (interactive) multiple user testing, roll out and roll back with the ability to audit and track who made what changes when to accomplish what purpose
Web based user interface creation tools
PaaS offerings typically provide some level of support to ease the creation of user interfaces, either based on standards such as HTML and JavaScript or other Rich Internet Application technologies like Adobe Flex, Flash and AIR. Rich, interactive, multi-user environments and scenarios can be defined, tried out by real people (non-programmers), with tools that make it easy to log/single out features that annoy or frustrate either novices or experts. Creation tools allow interfaces to be defined for different user profiles by function or expertise. PaaS offers improved user experience by incorporating channels for real people feedback throughout creation, design, development, testing, roll-out, production...the entire life-cycle through to 'end-of-life" "reincarnation" or "next generation evolution" of the application.
Multi-tenant architecture
PaaS offerings typically attempt to support use of the application by many concurrent users, by providing concurrency management, scalability, fail-over and security. The architecture enables defining the "trust relationship" between users in security, access, distribution of source code, navigation history, user (people and device) profiles, interaction history, and application usage.
Integration with web services and databases
Support for SOAP
and REST
interfaces allow PaaS offerings to create compositions of multiple web services, sometimes called "mashup
s" as well as access databases and re-use services maintained inside private networks. Support for keeping the user/relationships (if multiple users)/device context and profile through the mashup across web services, databases and networks.
Support for development team collaboration
The ability to form and share code with ad-hoc or pre-defined or distributed teams greatly enhances the productivity of PaaS offerings. Schedules, objectives, teams, action items, owners of different areas of responsibilities, roles (designers, developers, tester, QC) can be defined, updated and tracked based on access rights.
Utility-grade instrumentation
PaaS offerings provide developers insight into the inner workings of their applications, and the behavior of their users. Some PaaS offerings use information about user behaviour to enable pay-per-use billing. Historical/usage evidence may help:
Visualization tools could show usage patterns, exposing functional or correlational relationships between:
Financial data collection and, possibly, forecasting, are required to determine who pays what to whom and when (how often).
Solution stack
In computing, a solution stack is a set of software subsystems or components needed to deliver a fully functional solution, e.g. a product or service....
as a service. In the classic layered model of cloud computing, the PaaS layer lies between the SaaS
Software as a Service
Software as a service , sometimes referred to as "on-demand software," is a software delivery model in which software and its associated data are hosted centrally and are typically accessed by users using a thin client, normally using a web browser over the Internet.SaaS has become a common...
and the IaaS layers.
PaaS offerings facilitate the deployment of applications without the cost and complexity of buying and managing the underlying hardware and software and provisioning hosting capabilities, providing all of the facilities required to support the complete life cycle of building and delivering web application
Web application
A web application is an application that is accessed over a network such as the Internet or an intranet. The term may also mean a computer software application that is coded in a browser-supported language and reliant on a common web browser to render the application executable.Web applications are...
s and services
Web service
A Web service is a method of communication between two electronic devices over the web.The W3C defines a "Web service" as "a software system designed to support interoperable machine-to-machine interaction over a network". It has an interface described in a machine-processable format...
entirely available from the Internet.
PaaS offerings may include facilities for application design, application development, testing, deployment and hosting as well as application services such as team collaboration, web service integration and marshalling
Marshalling (computer science)
In computer science, marshalling is the process of transforming the memory representation of an object to a data format suitable for storage or transmission...
, database integration, security, scalability, storage, persistence, state management, application versioning, application instrumentation and developer community facilitation. These services may be provisioned as an integrated solution over the web
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
.
Types
Add-on development facilitiesThese facilities allow customization of existing software-as-a-service
Software as a Service
Software as a service , sometimes referred to as "on-demand software," is a software delivery model in which software and its associated data are hosted centrally and are typically accessed by users using a thin client, normally using a web browser over the Internet.SaaS has become a common...
(SaaS) applications, and in some ways are the equivalent of macro language customization facilities provided with packaged software applications such as Lotus Notes
Lotus Notes
Lotus Notes is the client of a collaborative platform originally created by Lotus Development Corp. in 1989. In 1995 Lotus was acquired by IBM and became known as the Lotus Development division of IBM and is now part of the IBM Software Group...
, or Microsoft Word
Microsoft Word
Microsoft Word is a word processor designed by Microsoft. It was first released in 1983 under the name Multi-Tool Word for Xenix systems. Subsequent versions were later written for several other platforms including IBM PCs running DOS , the Apple Macintosh , the AT&T Unix PC , Atari ST , SCO UNIX,...
. Often these require PaaS developers and their users to purchase subscriptions to the co-resident SaaS application.
Stand alone development environments
Stand-alone PaaS environments do not include technical, licensing or financial dependencies on specific SaaS applications or web services, and are intended to provide a generalized development environment.
Application delivery-only environments
Some PaaS offerings lack development, debugging and test capabilities, and provide only hosting-level services such as security and on-demand scalability.
Open platform as a service
Lets the developer use any programming language, any database, any operating system, any server, etc.
Key characteristics
Services to develop, test, deploy, host and maintain applications in the same integrated development environmentDifferent PaaS offerings provide different combinations of services to support the application development life-cycle. Comprehensive PaaS should provide all service options in an integrated development environment within the actual target delivery platform, with source code control, version control, dynamic (interactive) multiple user testing, roll out and roll back with the ability to audit and track who made what changes when to accomplish what purpose
Web based user interface creation tools
PaaS offerings typically provide some level of support to ease the creation of user interfaces, either based on standards such as HTML and JavaScript or other Rich Internet Application technologies like Adobe Flex, Flash and AIR. Rich, interactive, multi-user environments and scenarios can be defined, tried out by real people (non-programmers), with tools that make it easy to log/single out features that annoy or frustrate either novices or experts. Creation tools allow interfaces to be defined for different user profiles by function or expertise. PaaS offers improved user experience by incorporating channels for real people feedback throughout creation, design, development, testing, roll-out, production...the entire life-cycle through to 'end-of-life" "reincarnation" or "next generation evolution" of the application.
Multi-tenant architecture
PaaS offerings typically attempt to support use of the application by many concurrent users, by providing concurrency management, scalability, fail-over and security. The architecture enables defining the "trust relationship" between users in security, access, distribution of source code, navigation history, user (people and device) profiles, interaction history, and application usage.
Integration with web services and databases
Support for SOAP
SOAP
SOAP, originally defined as Simple Object Access Protocol, is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks...
and REST
Representational State Transfer
Representational state transfer is a style of software architecture for distributed hypermedia systems such as the World Wide Web. The term representational state transfer was introduced and defined in 2000 by Roy Fielding in his doctoral dissertation...
interfaces allow PaaS offerings to create compositions of multiple web services, sometimes called "mashup
Mashup (web application hybrid)
In Web development, a mashup is a Web page or application that uses and combines data, presentation or functionality from two or more sources to create new services...
s" as well as access databases and re-use services maintained inside private networks. Support for keeping the user/relationships (if multiple users)/device context and profile through the mashup across web services, databases and networks.
Support for development team collaboration
The ability to form and share code with ad-hoc or pre-defined or distributed teams greatly enhances the productivity of PaaS offerings. Schedules, objectives, teams, action items, owners of different areas of responsibilities, roles (designers, developers, tester, QC) can be defined, updated and tracked based on access rights.
Utility-grade instrumentation
PaaS offerings provide developers insight into the inner workings of their applications, and the behavior of their users. Some PaaS offerings use information about user behaviour to enable pay-per-use billing. Historical/usage evidence may help:
- determine whether services are of value to users/customers,
- compare the value of different services, and
- track activity based costs and revenues.
Visualization tools could show usage patterns, exposing functional or correlational relationships between:
- services and/or user interactions,
- the value to the user or users, and
- the cost of alternative service paths such as web and cell phone
Financial data collection and, possibly, forecasting, are required to determine who pays what to whom and when (how often).
See also
- Cloud computingCloud computingCloud computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a utility over a network ....
- Software as a serviceSoftware as a ServiceSoftware as a service , sometimes referred to as "on-demand software," is a software delivery model in which software and its associated data are hosted centrally and are typically accessed by users using a thin client, normally using a web browser over the Internet.SaaS has become a common...
- Infrastructure as a service
- IT as a Service
External links
- The Ever-Growing List of PaaS Companies and PaaS Projects
- European Project 4CaaSt - Building the PaaS Cloud of the Future; funded by the EU 7th Framework Programme Internet of Services, Software and Virtualisation.