Grid Computing - Guide to Cloud Computing for Business and Technology Managers - page 253

can be used with LDAP and the DUROC library that supports
resource co-allocation.
e. The application layer involves the user applications that are deployed
on the grid. It is important to note that not any user application can
be deployed on a grid. Only a grid-enabled or gridified application,
that is, an application that is designed or adjusted to run in parallel
and use multiple processors of a grid setting or that can be executed
on different heterogeneous machines, can take advantage of a grid
infrastructure.
12.7 Grid Computing Standards
One of the challenges of any computing technology is getting the various
components to communicate with each other. Nowhere is this more critical
than when trying to get different platforms and environments to interoper-
ate. It should, therefore, be immediately evident that the grid computing par-
adigm requires standard, open, general-purpose protocols and interfaces.
Standards for grid computing are now being defined and are beginning to
be implemented by the vendors. To make the most effective use of the com-
puting resources available, these environments need to utilize common pro-
tocols. We are now indeed entering a new phase of grid computing in which
standards will define grids in a consistent way by enabling grid systems to
become easily built off-the-shelf systems. Standard-based grid systems have
been called by some third-generation grids or 3G grids.
First-generation or 1G grids involved local metacomputers with basic ser-
vices such as distributed file systems and site-wide single sign-on, upon
which early-adopter developers created distributed applications with cus-
tom communication protocols. Test beds extended 1G grids across distances
and attempts to create metacenters explored issues of interorganizational inte-
gration. First-generation grids were totally custom-made proofs of concept.
Second-generation or 2G grid systems began with projects such as Condor,
I-WAY (the origin of Globus), and Legion (origin of Avaki), in which underly-
ing software services and communication protocols could be used as a basis
for developing distributed applications and services. Second-generation
grids offered basic building blocks, but deployment involved significant cus-
tomization and filling in many gaps. Independent deployments of 2G grid
technology today involve enough customized extensions that interoperabil-
ity is problematic and interoperability among 2G grid systems is rather dif-
ficult. This is why the industry needs 3G grids.
By introducing standard technical specifications, 3G grid technology will
have the potential to allow both competition and interoperability not only