CROWN: A Service Grid Middleware for e-Science - Grid Computing: Infrastructure, Service, and Applications - page 11

1.2.4.1 Overlay-Based Distributed Resource Management

The overlay technique is an effective way of supporting new applications as
well as protocols without any changes in the underlying network layer. The
basic idea of the overlay network is to build a new network over the existing
physical network nodes according to some selected logical rules. In CROWN,
resources are managed by an information service overlay consisting of a set
of RLDS services [5]. These RLDS instances are linked with each other
according to a tree-based topology with carefully selected shortcuts and
exchange resource and request information with their logical neighbors.
Such a fully decentralized structure can provide better performance while
avoiding a single point of failure in the information systems.

1.2.4.2 Remote and Hot Deployment with Trust (ROST)

Traditionally, remote service deployment is supported in a cold fashion,
which means deploying a new service and restarting the service run-
time environment. Therefore, the hot service deployment [6], which does
not need to restart the runtime environment while deploying services,
has become increasingly important. To achieve this feature, an archive
format called a GAR i le (grid archive) is proposed to encapsulate all the
necessary i les and coni gurations for a grid service. The GAR i le can be
moved to a target service container through SOAP/HTTP protocols. The
target service container receives the GAR i le and uncompresses it to
update the container information without stopping the container.
Security issues are guaranteed through trust negotiation using the ATN
technique. ATN is a new approach to access control in an open environ-
ment, which, in particular, successfully protects sensitive information while
negotiating a trust relationship. With ATN, any individual can be fully
autonomous. Two individuals, who are in the same security domain, may
try to set up a trust relationship by exchanging credentials according to
respective policies. With the availability of remote and hot service deploy-
ment, many applications will benei t, such as load balancing, job migration,
and so on.

1.2.4.3 JSDL-Based Job Submission and BES-Based Job Scheduling

JSDL (Job Submission Description Language) and BES (Basic Execution
Service) are adopted in the CROWN scheduler, with extensions to Web
service-based job submission. Jobs can be submitted to the CROWN
scheduler via any JSDL-compatible client, such as GridSAM and gLite,
using a BES interface. Interoperability demonstrations are proposed in
AHM (All Hands Meeting) 2006 and SC (International Conference on
Super Computing) 2006, organized by the HPCP (High Performance
Computing Proi le) Working Group in OGF (Open Grid Forum).