Grid-Enabling Applications with JGRIM - Cloud, Grid and High Performance Computing: Emerging Applications - page 44

Figure 1. A layered view of JGRIM

upon gridification, the ordinary application code
does not get mixed with Grid-related code. This
improves maintainability, testability and portabil-
ity of the same source code to different Grid APIs
and environments. In addition, unlike most of the
aforementioned tools, the JGRIM API only have
to be explicitly used when performing application
tuning and, in such a case, the application logic is
not affected. Finally, because of the component-
based roots of its programming model, JGRIM is
similar to using popular component development
models for Java such as JavaBeans or EJBs. Given
the widespread adoption of both Java and such
models, our approach can benefit a large percent-
age of today's Java applications.

structure by leveraging the services provided by
existing Grid platforms. Conceptually, JGRIM
is a software/hardware stack comprising the fol-
lowing layers:

• Resource : represents the physical infra-
structure of the Grid (resources and trans-
port protocols).
• Service : provides sophisticated services
to applications (e.g. load balancing, bro-
kering, parallelism, security, etc.) by
means of existing Grid platforms (e.g. Ibis
(van Nieuwpoort et al., 2005), ProActive
(Baduel et al., 2006)) and resource man-
agement systems (e.g. Globus (Foster,
2005), Condor (Thain et al., 2003)). The
Service layer is often the Grid entry point
for gridification under most of the existing
approaches, this is, gridified applications
directly talk to Grid services.
• Middleware : comprises some metaser-
vices that act as a glue between applica-
tions and the Grid. A metaservice is a
representative of a set of related concrete
services. Examples include service dis-
covery, service invocation and application
tuning.
• Application : contains applications con-
sisting of a number of interacting compo-

JGRIM

JGRIM is an approach for creating and deploy-
ing conventional applications on service-oriented
Grids. Its goal is to allow applications to discover
and efficiently use Grid services without requir-
ing developers to provide code for it. JGRIM
provides a layer whereby component-based Java
applications are effortlessly transformed to appli-
cations that are furnished with specialized library
components (see Figure 1). These components
glue applications and the underlying Grid infra-