Database Reference
In-Depth Information
adding client code that provides a method for encoding requests as XML;
and adding a Resource Manager module which decodes requests and talks to
the underlying scheduler for the resource, to make reservations. The scheduler
needs to support reservations.
4.6.3 Reserving Network Resources Using HARC
One of the main goals of the EnLIGHTened Computing Project (2005-2007)
23
was to enable coordinated use of compute and network resources. This re-
quired network resources such as those in the EnLIGHTened testbed (shown
in Figure 4.7 (a)) to be managed using middleware; previously this task re-
quired sending emails to network administrators. To enable this, a HARC
network resource manager (NRM) component was developed.
59
In the case of compute resources, there are a number of schedulers that
HARC can communicate with (e.g., Moab, LoadLeveler), but there is no equiv-
alent product for optical networks. Currently, there are a number of prototype
network schedulers (e.g., References 25 and 68) however these are often site-
specific, so we wrote our own simple scheduler for the EnLIGHTened network.
The software on the optical elements (Layer 1 optical network switches
from Calient) in the testbed supports generalized multi-protocol label switch-
ing (GMPLS), and connections across the testbed can be initiated by sending
a command to a switch at either end of the connection. A dedicated light
path can be set up between any two entities at the edge of the cloud shown in
Figure 4.7 (b). These are either routers (UR2, UR3) or compute nodes (RA1,
VC1, CH1).
The NRM accepts requests for network connections on a first-come, first-
served basis. Requests specify the start and end points of the connection (using
the three-letter acronyms shown in the figure). The following command line
example requests eight cores on machines at Louisiana State University and
MCNC as well as a dedicated light path connecting them:
$ harc-reserve -c santaka.cct.lsu.edu/8 \
-c kite1.enlightenedcomputing.org/8 \
-n EnLIGHTened/BT2-RA1 -s 12:00 -d 1:00
4.6.4 Experiments Using HARC
HARC has been successfully used to co-schedule compute and network re-
sources in a number of large-scale demonstrations, most notably in the high-
profile EnLIGHTened/G-lambda experiments at Global Lambda Grid Work-
shop (GLIF) 2006 and Supercomputing Conference (SC)'06, where compute
resources across the United States and Japan were co-scheduled together with
end-to-end optical network connections.
25*
The HARC NRM has also been
*
Also see http://www.gridtoday.com/grid/884756.html. Accessed July 16, 2009.
