Platform as a service
Platform as a service or application platform as a service or platform-based service is a cloud computing service model where users provision, instantiate, run and manage a modular bundle of a computing platform and applications, without the complexity of building and maintaining the infrastructure associated with developing and launching application, and to allow developers to create, develop, and package such software bundles.
Development and uses
PaaS can be delivered in three ways:- As a public cloud service from a provider, where the consumer controls software deployment with minimal configuration options, and the provider provides the networks, servers, storage, operating system, middleware, database and other services to host the consumer's application.
- As a private service behind a firewall.
- As software deployed on public infrastructure as a service.
At the time of its closure, Zimki had several thousand developer accounts. It had demonstrated the technical viability of Platform as a Service, but also provided the first example of the perils of being dependent on a single provider. This was highlighted when the CEO announced at OSCON 2007 that Zimki would no longer be open-sourced and discussed the future of what was then called framework-as-a-service covering the importance of a market of providers based on an open-source reference model.
The original intent of PaaS was to simplify the writing of code, with the infrastructure and operations handled by the PaaS provider. Originally, all PaaSes were in the public cloud. Because many companies did not want to have everything in the public cloud, private and hybrid PaaS options were created.
PaaS provides an environment for developers and companies to create, host and deploy applications, saving developers from the complexities of infrastructure. PaaS can improve the speed of developing an app, and allow its user to focus on the application itself. With PaaS, the customer manages applications and data, while the provider or IT department manages runtime, middleware, operating system, virtualization, servers, storage and networking. Development tools provided by the vendor are customized according to the needs of the user. The user can choose to maintain the software, or have the vendor maintain it.
PaaS offerings may also include facilities for application design, application development, testing and deployment, as well as 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. Besides the service engineering aspects, PaaS offerings include mechanisms for service management, such as monitoring, workflow management, discovery and reservation.
Advantages and disadvantages
The advantages of PaaS are primarily that it allows for higher-level programming with dramatically reduced complexity; the overall development of the application can be more effective, as it has built-in/self up-and-down ramping infrastructure resources; and maintenance and enhancement of the application is thus easier.Disadvantages of various PaaS providers as cited by their users include increased pricing at larger scales, lack of operational features, reduced control, and the difficulties of traffic routing systems.
Types
Public, private and hybrid
There are several types of PaaS, including public, private and hybrid. PaaS was originally intended for applications on public cloud services, before expanding to include private and hybrid options.Public PaaS is derived from software as a service, and is situated in cloud computing between SaaS and infrastructure as a service. SaaS is software hosted in the cloud so that it does not reside or run on customer computers. IaaS provides virtual hardware from a provider with adjustable scalability. In IaaS, the server is managed by the user, whereas in PaaS by the provider.
A private PaaS can typically be downloaded and installed either in a company's on-premises data center, or in a public cloud. Once the software is installed on one or more machines, the private PaaS arranges the application and database components into a single hosting platform.
Hybrid PaaS is typically a deployment consisting of a mix of public and private deployments.