Dear All,

I am forwarding a Technical Report on CCGrid 2005, a TCSC sponsored conference,
held in Cardiff, UK. Pls read on...

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CCGrid 2005 Recap: The Closest Thing to Being There
By Omer Rana, CCGrid 2005 Program Chair, Cardiff University, UK and Colleagues
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The following article was written by: Omer Rana, Linda Wilson, David
Walker, John Oliver, Ali Shaikh Ali, Simone Ludwig, Ian Wootten of
Cardiff University (United Kingdom); Adarsh Patil of University
College (Cork, Ireland); and Brian Foley and Ligang He of Warwick
University (United Kingdom).

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The 5th IEEE Symposium on Cluster Computing and the Grid (CCGrid 2005)
was held in Cardiff, Wales. The event attracted over 300 delegates
from the United States, Europe and the Asia-Pacific region. It
featured four tutorials, over 75 papers in the main track, nine
workshops and a range of invited talks. The opening speech was given
by the Rt Hon Rhodri Morgan (First Minister for Wales), who welcomed
the delegates and emphasized the importance of knowledge intensive
industries and services as exemplified through e-Science. The
conference also featured 17 posters, on topics ranging from Grid
middleware to experiments over Grid infrastructure. Keynote talks were
delivered by Carl Kesselman (USC/ISI) on the recently released Globus
Toolkit 4.0 (GT4), and by Tony Hey (EPSRC) on the UK e-Science
Program. Carl Kesselman noted, in particular, changes in the security
infrastructure within GT4. Other invited talks were by David Pearson
(Oracle) on the Enterprise Grid Alliance, by Stuart Schechter (MIT
Lincoln Lab) on SSH/Cluster security, and Heiko Ludwig (IBM) on
WS-Agreement. The use of WS-Agreement to support contract management
was particularly highlighted by Ludwig, and examples of the use of
WS-Agreement were provided. Additional informational talks were
provided by Jorge Gasos on the European Grid Program, and by Peter
McBurney on the European AgentLink III Network. A "Work-in-Progress"
session was initiated at this event by Mark Baker (Portsmouth
University) and Daniel Katz (JPL/Caltech), and is likely to remain an
important part of this conference in the future. A short course on the
use of the Triana toolkit for distributed workflow was offered to the
delegates.

Although an attempt was made to ensure that both Grid and cluster
computing were equally represented at the event, Grid computing
dominated most of the sessions. It was useful to see that a number of
Grid projects which were initiated at the start of this conference
series are now beginning to deliver results. There was also interest
in trying to integrate ideas from cluster and Grid computing,
especially in trying to extend operating system concepts to
larger-scale distributed environments. Based on the presentations,
this appears to be a promising area of work, and many researchers are
now beginning to discuss the general notion of a "Grid Operating
System." This theme also received prominence in the talk of Jorge
Gasos from the European Commission. One aspect presented at the
conference was the capability to federate computational clusters
running MOSIX. The work provided useful insights into techniques for
developing a campus wide Grid -- consisting of clusters from different
departments running the MOSIX system.

The applications workshops attracted significant interest and involved
presentations discussing updates to, and application specific
requirements of, Grid infrastructure. The types of applications ranged
from support for electronic learning (e-learning) to bio-informatics
and other applications of health care. There was a significant overlap
in the papers presented at the electronic learning workshop and themes
addressed at the Semantic Grid workshop. The e-learning workshop also
included papers discussing experience of teaching Grid computing
courses to students -- and best practice that could be more widely
applied. Providing business models for Grid services remains an
important concern, and mechanisms for charging for such services were
considered in the Grid Economics workshop. This brought together
participants from the computer science and economics community to
address issues related to electronic contracts and managing strategies
for allocating Grid resources in some fair manner. This issue was also
covered through papers in the main track of the conference. An
excellent tutorial in this area was also delivered by Rajkumar Buyya
from Melbourne University. The tutorial provided an overview of Grid
Computing and mechanisms supported for job management based on an
economic model. There was also discussion of major industry players
working in the area. The tutorial discussed the GridBus, Nimrod-G and
the GridSim Grid Market Directory systems. A very comprehensive
coverage was provided, with particular focus on how economic models
could be used to support scheduling constrained by budget.

The workshop on Cluster Security (chaired by Bill Yurcik) featured
papers addressing disk management, network management and
"rejuvenation" mechanisms. The last of these is a particularly
interesting theme which demonstrates how a cluster can be recovered
after a failure has taken place. The authors also presented a model
for predicting faults within a cluster that could be used as the basis
for a rejuvenation strategy. Presentations and discussions about
cluster infrastructure issues associated with opening up particular
ports on a cluster to allow job submissions and the use of specialist
scheduling systems also formed an important part of the workshop. The
enthusiasm and involvement of the workshop chair led to a very
successful event, and one likely to continue at future CCGrid
conferences.

The Peer-2-Peer workshop received the largest number of submissions of
all the workshops. A variety of topics were considered, ranging from
efficient routing mechanisms, resource discovery techniques and the
important area of trust management. Providing incentive structures to
allow users to share content in the P2P environment was also
considered, with particular focus on specialist Grid nodes that host
such services.

Running Data Grid applications such as High Energy Nuclear Physics
(HENP) and weather modelling experiments involves working with huge
data sets possibly of hundreds of terabytes to petabytes in size that
are often kept over wide area networks. This can suffer from overheads
introduced by cross domain connectivity, a variety of different types
of middleware and unreliable infrastructure. This was referred to as
"performability"; that is, the joint consideration of performance and
dependability. This particular theme formed the basis of the 1st
International Workshop on Grid Performability. The properties of
performability that were investigated in the workshops were as
follows: responsiveness, availability, utilization, integrity,
throughput, accessibility, latency, reliability and privacy. The idea
was that by considering the performability of the Grid systems, and
hence providing predictions, administrators can achieve greater impact
on system effectiveness and user satisfaction. An example of the work
that was presented included discussion of an ontology for describing
performance data of Grid workflows. The ontology used to describe a
set of performance metrics are utilized for monitoring and analyzing
the performance of Grid workflows.

The Work in Progress session involved discussion about registries,
networks and messaging as well as workflow. The talks that formed the
basis of this session were expected to have a longer-term focus,
describing primarily issues that are of interest to the research
community, but still at an early stage of exploration. The interaction
between the audience, presenters and the organizers was essential to
provide success for a session of this kind.

The Semantic Grid workshop also attracted a significant audience, and
attempted to bring together individuals with expertise in Semantic Web
technologies and the application sciences. Prominent in this
particular session were the issues of preservation and representation
that are becoming evident with use of Grid computing in scientific
applications. Calls were made on a higher level of semantics for
representing both data and services, to ease the problems of data
harmonization such as scalability and data format differences which
will result without them. In addition to this, general ideas were
expressed with such infrastructures in place, such as the automated
composition of workflows.

Grid applications are often involved with large volumes of data
produced by data-intensive simulations and experiments on scientific
instruments. In order to guarantee seamless automation and
interoperation of distributed data, the need for adequate descriptions
such as semantic-based data descriptions, models, services and systems
becomes crucial. For example, the LHC (Large Hadron Collider) is
expected to be operational by 2006-2007, with the LHC Grid
functioning, to begin the production of simulation data consisting of
Petabytes of data. Sciences such as biomedical science and
bioinformatics produce smaller data sets but numerous, diverse and
widely distributed files stored on individual desktops and databases.

Papers were presented in the areas of resource descriptions,
semi-automatic preservation of scientific data, file-based data for
Grid services and data integration techniques. One particular paper
investigated data integration services in bioinformatics, whereby a
semantic data access and integration service based on the Grid
paradigm was introduced. This service uses ontologies for correlating
different data sets and is a fundamental component of the ProGenGrid
system. The ProGenGrid system is a Grid-enabled platform, which aims
at the design and implementation of a virtual laboratory where
e-scientists could simulate complex "in silico" experiments, composing
analysis and visualization tools available as Web services into a
workflow. A number of other papers were also presented on the general
Grid-based workflow theme, and this remains an important area of
concern to both infrastructure developers and application scientists.
Presentations included discussions of specialist workflow
specification languages (such as AGWL), the development of tools that
allow monitoring of tasks within a workflow session, and tools that
allow aggregation of services from different administrative domains
(JISGA and WebCom-G). Many such workflow techniques are also contained
in specialist Problem Solving Environments aimed at scientists within
a particular application area. Applications considered included
Computational Electromagnetics, real-time systems, and genome
comparison. To date, there still does not appear to be any consensus
on a particular workflow technique -- and often it is difficult to
combine workflow tools developed by different groups.

The use of a shared memory space (such as a tuple space) also remains
an important topic within the Grid and cluster community. The workshop
on Distributed Shared Memory (DSM) featured a number of papers
discussing issues of supporting synchronization within a shared
memory, issues of consistency management, and performance issues
associated with the use of particular networking infrastructure (such
as InfiniBand). The use of DSM to support "Mobile Grids" was a
particularly interesting contribution. The authors discussed how the
use of a Shared Virtual Memory paradigm could be viewed as an
unstructured DSM. The SVM concept was then used to connect PDAs and
similar mobile devices within a Grid.

Network and I/O management also remains an important topic at CCGrid,
with a workshop and three sessions devoted to it. Issues discussed in
the workshop and the main track included deployment of resources
within a "Lambda" network, and in particular how lightpaths allocated
to particular application streams could be more efficiently managed.
Advanced reservation techniques to support a particular Quality of
Service were also discussed. Requirements for a reliable multicast
technique over a production network was discussed, along with an
investigation of how this could be achieved using the NORM protocol
family. The authors also provided a useful discussion of existing
Grid applications (mainly multimedia based) that require the use of
multicast. Papers discussing the provision of efficient I/O over a
cluster provided formed the other theme in the communications track.
As part of the tutorial on high performance I/O, the presenter
discussed file I/O at various levels of abstraction, including POSIX
I/O, MPI file communication primitives, parallel file systems, and
libraries that allow structured access to complex file formats. Some
of the implementation tradeoffs, performance characteristics, and
optimization work on these libraries were described. Since high
performance computing covers a wide range of different kinds of
networking and storage hardware, tools that work well on one system
cause severe bottlenecks in others. Insight was given into when and
where it is appropriate to use one level of abstraction over another,
and how to provide "hints" to the various libraries to allow them to
extract the best out of a given system.

An area that was not represented at CCGrid 2005 included work on
sensor networks, and integration of these with Grid middleware.
Although there is significant interest in this area (at the GGF and
various research groups), especially in health care provision
(http://www.healthgrid.org/), there was not significant representation
of this theme.

This summary of CCGrid cannot fully cover the variety of work
presented at the conference. An attempt is made to present some key
themes at the conference, and to highlight some new and emerging areas
of interest to the community. Interested readers are referred to the
proceedings of CCGrid 2005 for additional information. The next CCGrid
conference is scheduled to take place in Singapore in May 2006. CCGrid
2005 proceedings are available on CD-ROM for purchase, please contact
admin@... for more information.
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