The raw data rate of the image capture process is very high, of the
order of 2.5 Gb/s. A stated aim had been to modify the hardware to allow sufficient
buffering and communications bandwidths to be incorporated into
our equipment to allow Grid parallelism. Working jointly with the
team funded by EU project Racine-S, we reconfigured the capture
hardware so that each of eight capture machines was upgraded to a
dual processor configuration with an attached 160GB RAID array. Improved
communications links were attached to the machines. This both allowed
the captured data to be stored on local fast disks and gave us an
improved local parallel processing resource of 16, 2.2Ghz Athlons.
We also negotiated access to the IBM Blue Dwarf cluster at NeSC as
an additional processing resource of different architectural characteristics
and featuring fast processors.
We designed and developed our own, IP-based protocols for the communication
of data and controls between the JPie processes. This was because GridFTP
does not support memory-to-memory transfers and the server is not available
for Windows. The protocols are part of the JPie
Java code.
JPie can make use of various resources from a pool, but requires a mechanism to
identify, check for availability and access these resources. Effort in this
workpackage was directed towards the design and implemenation of our
resource locator. The model we have proposed has three components: the Initiator,
the Locator and the ServEnt (Server Entity), jointly referred to as the ILS model.
A typical interaction is as follows: a ServEnt advertises its hardware
characteristics and availability for tasks by informing the Locator, which maintains
a list of such information. An Initiator wishing to launch a task requests suitable
resources from the Locator. The Locator returns a list of resources, from which
the Initiator then confirms the first resource availability directly with the ServEnt,
and then if available submits the task. On task completion the ServEnt passes the
job metrics back to the Initiator. The ILS software is independent of (but utilised
by) JPie.
Download the Initiator-Locator-Servent (ILS) software, v1.2 (zip, 1,040KB),
Requirements and Solutions Survey
(PDF, 238KB)
and Installation
Guide (PDF, 232KB).
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