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Hi Chip,<br>
<br>
No, we certainly don't expect that kind of data volume. I suspect
those numbers from LHC have a little "PR" inflation in them though.
They are probably counting backups, and duplicates stored at the tier-1
and tier-2 institutions. If you look at the CERN website here:<br>
<br>
<a class="moz-txt-link-freetext" href="http://public.web.cern.ch/public/en/lhc/Computing-en.html">http://public.web.cern.ch/public/en/lhc/Computing-en.html</a><br>
<br>
it claims a 15 petabyte/year number which is much more in line with the
rates given in my table (when you include some 1200MB/s Pb-Pb running
for ALICE). Anyway, I don't know that the exact values are really worth
quibbling about. The "much less than 1% of LHC" claim just seemed
inconsistent with my understanding of what their DAQ systems will be
writing to disk compared to ours.<br>
<br>
Regards,<br>
-David<br>
<br>
Chip Watson wrote:
<blockquote cite="mid:4BEFF2DE.40703@jlab.org" type="cite">
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"As the LHC experiments begin to take collision data in a new energy
range over the next few months, new ground will be broken in our
understanding of the nature of matter and space-time and in the search
for new particles. In order to fully exploit the potential for
scientific discoveries during the next year, more than 100 petabytes
(1017 bytes) of data will be processed, distributed, and analyzed using
a global grid of 300 computing and storage facilities located at
laboratories and universities around the world, rising to the exabyte
range (1018 bytes) during the following years."<br>
<br>
I sure hope you guys are not aiming at exabyte in 2014, like LHC is.
If so, there is a problem.<br>
<br>
Chip<br>
<br>
David Lawrence wrote:
<blockquote cite="mid:4BEED902.3070207@jlab.org" type="cite">
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<br>
Hi Chip,<br>
<br>
Thanks for this summary. I'm curious, however, where the "... much
less than 1% of LHC's ..." number comes from. With the exception of
Pb-Pb scattering in Alice, GlueX has an expected bandwidth to mass
storage that is comparable to any of the LHC experiments. See for
example the last slide in:<br>
<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1523">http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1523</a><br>
<br>
Regards,<br>
-David<br>
<br>
<br>
Chip Watson wrote:
<blockquote cite="mid:4BEEC005.2030000@jlab.org" type="cite">
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Richard,<br>
<br>
The cost of the items you are recommending is significant:<br>
<br>
1. The cost of developing location-independent access to MSS files is
probably an additional $100K above current capabilities, perhaps as
much as twice that depending upon details of requirements.<br>
<br>
2. The cost of storage is independent of where the work is done -- the
full requirements are meant to be in the 12 GeV Computing Plan, and if
you don't believe the requirements are correctly captured, please work
with Graham Heyes to correct that.<br>
<br>
3. The cost of maintaining such a full computational grid capability
is approximately $180K per year for staff, plus some modest hardware
costs for appropriately provisioned gateways, depending upon detailed
requirements. (And if tier-N sites were to appear, they would also
require grid administrative overhead beyond JLab's costs.)<br>
<br>
Jefferson Lab is committed to satisfying the requirements for 12 GeV,
but does not start a priori with an assumption of a multi-tiered grid
-- that is an implementation choice, not a requirement. There are a
number of political and scientific reasons why LHC made that choice,
many of which are not valid for Jefferson Lab. The current 12 GeV
requirements do not drive us toward a computational grid solution, and
so the laboratory has as its working plan a much more cost effective
mostly centralized solution. Of course if the requirements are not
correct, the solution may not be correct, but any significant change in
the scale of the requirements will have to compete for funds with
detector enhancements, accelerator operations, and many other costs.
Offline computing is not part of the construction project, but only the
operations budget.<br>
<br>
I began the process of requirements collection so that Jefferson Lab
could move in the direction of a requirements driven solution, with
sufficient lead time so that it would not be left until the end and
thus under provisioned. HEP has a history of long lead time
activities, with LHC being a premier example. Bear in mind, however,
that our requirements are much less than 1% of LHC's, and our budget is
correspondingly much smaller.<br>
<br>
regards,<br>
Chip<br>
<br>
<br>
Richard Jones wrote:
<blockquote cite="mid:4BEEB635.9020203@uconn.edu" type="cite">Offline
folks,<br>
<br>
One thing stands out to me in reading through this plan is the lack of
any accommodation for the interaction between the Jlab computer center
and computing facilities at user institutions. For comparison, it is
helpful to look at the computing plan for any of the LHC experiments,
where the plan is oriented around distribution and global access to
data and computing resources. Things that I would like to see in the
Gluex Offline Computing Plan that eventually get propagated through
appropriate channels to someone like Graham Hayes are the following:<br>
<ol>
<li>Location-independent mechanisms for remote access to MSS
files
(with appropriate authentication/authorization) without logging in on a
Jlab machine over ssh, both reading and writing.</li>
<li>Provision for allocation of space on MSS for archival of
intermediate data sets generated off-site, eg. MonteCarlo and final
data samples used in a PWA that was the basis of a particular
publication.</li>
<li>Support of grid protocols for transparent scheduling and
migration of jobs across available resources within the collaboration,
so that when a particular resource is overbooked jobs can flow across
site boundaries to where resources are available.</li>
</ol>
-Richard Jones<br>
<br>
<blockquote type="cite" cite="mid:4BED9F25.5080509@jlab.org">
<pre wrap="">Folks,
I've just posted a document from Graham Heyes, describing the Lab's
scientific computing plan for the current fiscal year. It is
GlueX-doc-1530. The document page is
<a moz-do-not-send="true"
href="http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1530">http://argus.phys.uregina.ca/cgi-bin/private/DocDB/ShowDocument?docid=1530</a>
I've posted it on our DocDB not because it is GlueX-specific (it is not)
but just so we have a well-defined place to find it and to reference it.
-- Mark
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<pre class="moz-signature" cols="72">--
------------------------------------------------------------------------
David Lawrence Ph.D.
Staff Scientist Office: (757)269-5567 [[[ [ [ [
Jefferson Lab Pager: (757)584-5567 [ [ [ [ [ [
<a moz-do-not-send="true" class="moz-txt-link-freetext"
href="http://www.jlab.org/%7Edavidl">http://www.jlab.org/~davidl</a> <a
moz-do-not-send="true" class="moz-txt-link-abbreviated"
href="mailto:davidl@jlab.org">davidl@jlab.org</a> [[[ [[ [[ [[[
------------------------------------------------------------------------
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<pre class="moz-signature" cols="72">--
------------------------------------------------------------------------
David Lawrence Ph.D.
Staff Scientist Office: (757)269-5567 [[[ [ [ [
Jefferson Lab Pager: (757)584-5567 [ [ [ [ [ [
<a class="moz-txt-link-freetext" href="http://www.jlab.org/~davidl">http://www.jlab.org/~davidl</a> <a class="moz-txt-link-abbreviated" href="mailto:davidl@jlab.org">davidl@jlab.org</a> [[[ [[ [[ [[[
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