Economy Informatics, 1-4/2006 39
Grid and Web Services STANDARDS
Senior lect. Carmen TIMOFTE, PhD
Informatics in Economy Department,
Academy of Economic Studies Bucharest, Romania
Grid is a type of parallel and distributed system that enables the sharing, selection, and ag-
gregation of resources distributed across "multiple" administrative domains based on their
(resources) availability, capability, performance, cost, and users' quality-of-service require-
ments. Service orientation of the Grid makes it a promising platform for seamless and dy-
namic development, integration and deployment of service-oriented applications. Flexibility
are essential characteristics of Web services technologies such as WSDL (Web Services De-
scription Language), SOAP (Simple Object Access Protocol), and UDDI (Universal Descrip-
tion, Discovery, and Integration).
Keywords: GGF, EGA, OGSA, OGSI, UDDI, SOAP, WSDL.
Web services & grid computing earmarked for capital investments. We’ve
Web services are Internet-based, modular created large, underutilized, complex envi-
applications that perform a specific business ronments that are costly to maintain. So there
task and conform to a particular technical is a huge need to do this better, and the pre-
format. The technical format ensures each of vailing thinking at this point seems to be that
these self-contained business services is an grid is the answer.
application that will easily integrate with The technology behind grid isn't new. Its
other services to create a complete business roots lie in early distributed computing pro-
process. This interoperability allows busi- jects that date back to the 1980s, where sci-
nesses to dynamically publish, discover, and entists would connect multiple workstations
aggregate a range of Web services through to let complex math problems or software
the Internet to more easily create innovative compilations take advantage of idle CPUs,
products, business processes and value dramatically shortening processing times. For
chains. years, vendors and IT departments eyed this
Grid computing joins together many individ- opportunity to dramatically increase process-
ual computers, creating a large system with ing power by employing existing resources.
massive computational power that far sur- But only recently have the tools arrived to
passes the power of a handful of supercom- put general business applications to work on
puters. Because the work is split into small a grid.
pieces that can be processed simultaneously,
research time is reduced from years to Standards, pricing and other grid hurdles
months. The technology is also more cost- Creating tools that work in distributed, het-
effective, enabling better use of critical erogeneous environments is a field ripe for
funds. standards, something both grid vendors and
Grid computing is not a futuristic technology. customers realize.
World Community Grid is at work right now Understanding that concern, vendors and re-
applying this technology to exciting research searchers are involved in several standards
projects that can benefit us all. By many ac- bodies.
counts, average system utilization across or- - Global Grid Forum (GGF) - whose mem-
ganizations is 15% to 20% today, while ob- bers include Ascential, DataSynapse, Hew-
viously the ideal would be around 80%. lett-Packard, IBM, Microsoft, Oracle, Plat-
What’s more, some 20% of IS budgets go to form Computing and Sun -works to develop
operations, marginally less than the 25% standards intended to create a wide range of
40 Economy Informatics, 1-4/2006
interoperable grid-computing environments and deployment of Web Services. In 2004,
and applications. GLOBUSWORLD - Akamai, The Globus
- Enterprise Grid Alliance (EGA) - formally Alliance, HP, IBM, Sonic Software and
announced by Oracle, HP, Sun and others TIBCO today proposed new Web services
(though notably not Microsoft, IBM or Plat- specifications that will integrate Grid and
form Computing) - has set goals of providing Web services standards.
standards aimed at grid-enabled enterprise The new WS-Notification and WS-Resource
applications, what it claims will be a subset Framework represent the first time a
of the GGF's work. common, standards-based infrastructure will
- Globus Alliance - was formed by a group be available for business applications, Grid
of research organizations, including Argonne resources and systems management. These
National Laboratory and the University of new specifications will help customers lower
Chicago and sponsored by the Defense Ad- costs, speed deployment and enable
vanced Research Projects Agency and the integration across and outside of the
National Science Foundation. The group im- enterprise.
plements standards through its Globus Tool- These new Web services specifications will
kit, an open-source development suite that significantly extend the types of enterprise
lets software makers jump-start their grid de- solutions customers can easily deploy. These
velopment. Current standards include: new specifications are important for key bu-
o the Open Grid Services Architecture siness applications and provide customers
(OGSA), with the ability to utilize a common Web
o the Open Grid Services Infrastructure services based infrastructure that support of
(OGSI) Grid and management based solutions.
o the Web Services Resource Framework, The WS-Notification specification and the
which will supplant OGSI later this year, ac- WS-Resource Framework will provide a
cording to GGF, and allow grid software scalable pub/sub messaging model and the
makers to use common Web services stan- ability to model stateful resources using Web
dards to identify and utilize grid-computing services. Stateful resources are elements that
resources. can be modeled including physical entities
Other issues arise around licensing and pric- (such as servers) to logical constructs (such
ing. Vendors who move their products to grid as business agreements and contracts). Ac-
must figure out ways to price their software. cess to these stateful resources enables
Per-CPU or per-seat pricing often makes customers to realize business efficiencies
sense in a world where those numbers stay including just in time procurement with
relatively static, but with grid, an application multiple suppliers, systems outage detection
could run on 500 processors one minute and and recovery and Grid-based workload
none the next. Being charged for every one balancing.
of those processors could drive much of the The WS-Resource Framework includes:
cost benefit out of grid for customers, but - Modeling Stateful Resources with Web
adopting a "buy it once, use it everywhere" services - describing how to utilize the
model could push vendors out of the grid related specifications to model the resources
business. Ultimately, per-use price models— in the context of Web services.
likely based on specifications supplied in the - WS-Resource Properties - defines how
OGSA—could dominate, but the tools for data associated with a stateful resource can
tracking such usage have yet to be fully de- be queried and changed using Web services
veloped. technologies. This allows lients to build
applications to efficiently read and update
Grid and web services standards to con- data associated with resources, such as
verge contracts, servers or purchase orders.
New specifications will ease development - WS-Resource Lifetime- which allows the
Economy Informatics, 1-4/2006 41
user to specify the period during which a ments from Web services and grid comput-
resource definition is valid. For example, WS ing:
Resource Lifetime can automatically update Resource virtualization: each grid com-
suppliers from all systems once contracts or ponent is considered a service.
service level agreements expire, or deleting Standard interface definition mecha-
products from inventory systems that are no nisms: enabling multiple protocol bind-
longer being manufactured. ings and transparency between local or
OGSA Standard foundation services: defining
The Open Grid Services Architecture service semantics, reliability and security
(OGSA) combines technologies to unlock models, and core functions such as life-
and exploit grid-attached resources. OGSA cycle management, or discovery.
defines mechanisms to create, manage, and Implementation independence: support
exchange information between Grid Services, for multiple development languages and
a special type of Web service. The architec- hosting environments including Java,
ture uses WSDL extensively to describe the COBOL, C, J2EE, CICS, and .NET.
structure and behavior of a service. Service Since a grid consists of both existing and
descriptions are located and discovered using new hardware and software, multiple varia-
Web Services Inspection Language (WSIL). tions of communication protocols, security
By combining elements from grid computing schemes, and transaction management sys-
and Web services technologies, OGSA estab- tems exist and cooperate at the same time.
lishes an extensible and interoperable design Today's grids tend to be a patchwork of pro-
and development framework for Grid Ser- tocols and noninteroperable "standards" and
vices that includes details for service defini- difficult-to-reuse "implementations." The
tion, discovery, and life-cycle management. OGSA uses Web services technologies like
OGSA defines and standardizes a set of WSDL, SOAP, and WSIL to abstract plat-
(mostly) orthogonal multipurpose communi- form and implementation differences, giving
cation primitives that can be combined and transparent access to grid services.
customized by specific clients and services to Fundamental to OGSA are WSDL and inter-
yield powerful behavior. OGSA defines faces for dynamic discovery and life-cycle
standard interfaces (portTypes in WSDL management for a specific type of Web ser-
terminology) for basic Grid services. vice - a Grid Service. WSDL conventions
Grid applications use grid tools and middle- and extensions are used to describe and struc-
ware components to interact with the fabric. ture services, while core service activities are
OGSA introduces several service concepts expressed using WSDL interfaces and behav-
that need to be adopted in order to qualify as iors. Every Grid Service instance has a
Grid services. Necessary components are fac- unique and immutable name called the Grid
tories, registries, and handle maps. Addi- Service Handle. Lifetime management is
tional mechanisms that can be used to build provided by mandatory support for the opera-
our data grid are notification and lifetime tions Destroy and SetTerminationTime.
From a software-design perspective, a grid Grid application and companies
can be viewed as a collection of self- The most important grid players and they ap-
contained computing services that can be de- plication, in the alphabetical order, are:
scribed, published, located, and invoked over • Ascential (ascential.com): Enterprise In-
any type of network. Services are location- tegration Platform that supports data integra-
independent and dynamic, span multiple tion grids.
computing architectures, and reach across • Avaki (avaki.com): Avaki Data Grid cre-
administrative domains. The design princi- ates a unified catalog of data across a net-
ples of OGSA reflect a combination of ele- work.
42 Economy Informatics, 1-4/2006
• DataSynapse (datasynapse.com): Grid- architectures, or a Web service seems to
Server lets customers move existing applica- add up to a potent force, a sensible image
tions to grid environment of the future.
• Dell (dell.com): Partnered with Platform We have new applications on the horizon that
Computing (see below) to provide grid- will give us further impetus, one being ef-
enabled systems for CPU-intensive comput- forts to instrument anything and everything
ing purposes. of value - sensors in/on everything in every
• Enterprise Grid Alliance field, from medicine to military and manu-
(gridalliance.org): Group formed by Oracle, facturing. This will create a flood of raw,
HP and others to create enterprise-oriented real-time streaming data.
• Global Grid Forum (ggf.org): Standards References
body that creates and publishes grid comput- www.cio.com (2004) True Grid - Grid Tech-
ing standards. nology.
• The Globus Alliance (globus.org): www.worldcommunitygrid.org/ Community
Group offers open-source development kits Grid - About Us - Grid Computing Ba-
based on Global Grid Forum and Oasis. Will sics.htm, (2004).
likely include other standards. www.globus.org/Globus Project Open Grid
• Hewlett-Packard (hp.com): Utility Data Services Architecture.htm, (2004).
Center provides rapid reallocation of comput- www.nwfusion.com, Grid and the Future of
ing resources. Works on a variety of corpo- the Network Machine.htm, (2005).
rate grid products and services. www.sys-con.com/webservices/ Web Ser-
vices Journal, (2004).
• IBM (ibm.com/grid): Grid is a central
www.infoworld.com, Sun combines grid
part of IBM's autonomic computing model.
computing, Web services, (2003).
Numerous products and partnerships in
wwws.sun.com/software/gridware , (2005).
• Oracle (oracle.com/grid): Released Ora-
cle 10g database early this year. Built-in sup-
PRESS RELEASE Grid and Web Services
port for grid computing resources.
Standards to Converge.htm, (2004).
• Platform Computing (platform.com):
Software that consolidates computing re-
sources and provides an architecture for grid-
• SAP (sap.com): Currently piloting a pro-
ject to grid-enable SAP applications.
• Sun Microsystems (sun.com): N1 Grid
engine combines grid and clustering.
• United Devices (ud.com): Offers enter-
prise grid software and hosting service for
The combination of the confluence of devel-
- The maturation of grid technology
- General consensus that the future of
computing is about networked, low-cost
- And the emergence of service oriented