Information Technology Reference
In-Depth Information
• Simple Object Access Protocol (SOAP) - the standard for transmitting data
• Web Service Description Language (WSDL) - the standard for unified descrip-
tion of services
• Universal Description Discovery and Integration (UDDI) - is a platform-inde-
pendent, based registry for services.
All Web Services standards are Extensible Markup Language (XML)-based,
which is machine readable and enables service to service communication. Based
on the core standards listed above, further standards were developed that support
the description of more complex constructs that are based on Web Services. One
example of such a standard is the Business Process Execution Language for Web
Services (BPL4WS) (Papazoglou et al. 2007).
The definitions above show that SOC has similarities with Grid Computing,
i.e. what the Grid Computing vision is with regards to sharing and interopera-
bility on the hardware level is the vision of SOC on the software and application
level. Another commonality among the two concepts is the notion of services. As
described in section 3.3, the Grid Computing architecture consists of protocols, i.e.
services necessary to enable description and sharing of available physical resources.
A convergence of the SOC and Grid Computing paradigms offers several opportu-
nities:
• By applying the Web Service standards, Grid protocols and services can be
encapsulated and described in a standardized manner (see fig. 3.7). At the same
time existing technology for Web Service discovery, combination and execution
might be applied.
Application
Service
Collective
Service
Resource
Service
Connectivity
Service
Fabric
Fig. 3.7:
Enhancement of the generic Grid architecture with Service-oriented Computing
(adapted from Foster et al. 2008)
• Once the complementary paradigms, Grid Computing and SOC are based on the
same standard, their combination becomes possible. This means that not only
hardware and system resources become sharable, but also applications running
on them.
