Tutorial: Platform as a service is exposed to its users as a familiar middleware service, but below the &quot;surface,&quot; there are layers of cloud-specific technology that deliver the scalability, availability, elasticity and self-service that are essential to the cloud computing experience. Platform as a service is middleware &quot;in the sky.&quot; Although offered as a service, its functional role remains the role of the middleware — platform, integration or other middleware type. Because there are different types of middleware offerings (application servers, integration brokers [ESBs], business process management suites [BPMSs], portal products, messaging products, etc.), each can also be delivered as a service. In some cases, these middleware services are delivered stand-alone as specialized PaaS services (StormMQ is a specialist messaging service). More often, the same cloud service provider offers multiple middleware services to meet the requirements of real-world projects (force.com includes services of a DBMS, an application server and an application development tool). Over time, most PaaS providers will aim to deliver a growing set of middleware functions. To be implemented as a cloud service, a PaaS service must not only deliver its middleware functionality, but also possess the features that make it cloud-worthy (the cloud performance foundation) and cloud-enabled (cloud behavior foundation). The cloud performance foundation is responsible for scalability and availability to match the potential demand of the global cloud user base. The cloud behavior foundation delivers resource sharing, multitenancy, elasticity, self-service and other characteristics expected of a cloud service. The common, shared development and management environments complete the picture of a well-designed PaaS platform, whether it offers only a few middleware services or is a comprehensive end-to-end PaaS.
Platform-as-a-Service and WSO2 Stratos Paul Fremantle CTO and Co-Founder www.wso2.com [email_address] #pzfreo
Gartner Reference Model for Platform as a Service Hardware Integrated PaaS Platform Management, Monitoring, Governance, Provisioning System Infrastructure or System Infrastructure Services (IaaS) PaaS Service Offerings PaaS Technology Core Integrated PaaS Application Modeling, Design, Development, Maintenance, Life Cycle Management Applications PaaS IaaS SaaS Cloud Performance Foundation Cloud Value Foundation ( Shared Resources, Multitenancy, Self-Service, Elasticity, Real-Time Versioning, Metadata Management, Subscription/Use Billing) (In-Memory Computing, Grid/Massive Scale, Auto-Scaling, SLA Enforcement, Use Tracking, High Availability, Security, Data Integrity, Parallel Processing) Application Platform Integration Platform Business Process Management Platform Cloud Database Platform Other User Experience Platform