Along with the service orientation paradigm shift, IT services of different forms have been discussed at [2, 6]. Under SOI, the hardware need not play the customary passive role, providing only the processing power needed for computation. A key observation is that service orientation need not be a software-only proposition; hardware can and should provide services as well. Therefore, we propose the term "platform as a service" or PaaS to denote the idea that a hardware platform can be architected with service-oriented concepts from the very beginning, having built-in service abstractions available at the bare-metal level.

PaaS can be defined as hardware- and firmware-based autonomous devices that provide standard services to interact with other entities in an SOA. PaaS devices constitute basic building blocks for SOI and interact with other orchestration and management services from SOM as well as provide seamless services to the SOA layer.

A PaaS device must have the following defining characteristics:

• Service abstractions: Service abstractions define basic service units, hiding hardware and firmware implementation details. This abstraction is essential in keeping the device autonomous and interoperable with other service providers or consumers. Examples of service abstraction could be device status information, basic device controls (power on/off), provisioning, re-provisioning, systems configurations, utilization metering, etc.
• Standard interface: In a service-oriented environment, standard service interfaces are critical to interoperability and sharing of services across heterogeneous platforms. This is especially true with PaaS as there are many different SOA applications running on top of it, and hardware platforms should be designed for general IT infrastructures. It is not practical to expose PaaS services through proprietary interfaces, as it will limit service adoption and defeat the purpose of service orientation. Therefore, PaaS has to support open service standards like Web Services–the same standards that software and applications can understand. In this way, other SOI, SOA, and SOM components can interact with PaaS devices in the same way that they interact with software components.
• Change tolerant: Hardware is often seen as very efficient and reliable, but not very flexible and adaptive to change. With PaaS, the concept of hardware could change fundamentally. Hardware becomes flexible and adaptive to provide basic services upon installation with or without software. Platform services could also aggregate at group levels across multiple platforms and interact with other services in the environment as part of the overall SOI.
• Policy driven: As part of an overall solution, a PaaS device has to understand the response to policies that direct IT environments. PaaS typically has a built-in policy engine to interpret policies down-loaded from the IT environment. At a minimum it will be able to respond to instructions and directives from the upper layers of IT management services defined in terms of orchestration, SLAs, and Quality of Service (QoS).

PaaS will bring new opportunities and challenges for hardware designers and vendors. Provisioning hardware at higher levels of abstraction and enhanced security will require significant rethinking, especially when these functions are available at the bare metal state. Nonetheless, PaaS will beneficial overall in accelerating the adoption of SOA and it will increase the productivity of IT professionals facilitating business through building end-to-end solutions.

Intel® AMT–a PaaS example

Intel announced a new platform management technology in 2005 to reduce the complexity and cost of platform management for businesses–Intel AMT.

We illustrate the PaaS concept by pointing out some of the features in Intel AMT, showing that PaaS is technically feasible and some features are available today. The following table summarizes key features and services provided by Intel AMT. They are built-in at the platform level as combinations of hardware and firmware.

Table 1: Key features and services of Intel® AMT

With the OS up and running, Intel AMT can operate in in-band (IB) mode and out-of-band (OOB) mode. In IB mode, Intel AMT interacts with the OS and management console to perform requested platform management functions. When the OS is not available, either because it has not been provisioned (bare metal state) or because it has crashed, Intel AMT can operate in OOB mode. It continues to provide basic platform management functions and is accessible through a management console.

Intel AMT is an example of PaaS available in products today—it is autonomous, has clearly defined platform management services that are always available, and exposes those services through standard interfaces. The following section describes a PoC project conducted by Intel IT based on Intel AMT and WS-Management that demonstrates how these work in an autonomic fashion in a real IT environment. For further details of WS-Management and other WS* standards, please refer to [9] in this issue of the Intel® Technology Journal.