<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
</head>
<body bgcolor="#ffffff" text="#000000">
Well, if there is some concern that throttling might be a problem, then
trying a run with it turned off seems good.<br>
<br>
I'm gathering from this exchange that this is not possible?<br>
<br>
Ben Clifford wrote:
<blockquote
cite="mid:Pine.LNX.4.64.0706211531180.15250@dildano.hawaga.org.uk"
type="cite">
<pre wrap="">But that isn't the base problem being investigated, right?
On Thu, 21 Jun 2007, Ian Foster wrote:
</pre>
<blockquote type="cite">
<pre wrap="">My original question was whether we could turn throttling off altogether. I'm
not sure if that was answered?
Tiberiu Stef-Praun wrote:
</pre>
<blockquote type="cite">
<pre wrap="">I did not look very deep into the throttling, mainly because I have to
wait for my turn at using the Argonne cluster because of the large
reservations that Ioan does for MolDyn
Anyway, here is my experience (which Ian asked me to write down, but
I'm still trying to improve on):
- whatever one asks from Falkon, one seems to get, with the caveat
that Falkon might release nodes when configured to look at an idle
timer. In the case of the Econ workflow, I had 26 long running jobs,
so I requested 30 nodes (which Falkon got for me)
- there is a swift config file, $DVS_HOME/libexec/scheduler.xml in which I
set
<property name="jobThrottle" value="30"/>, but that seemed not to be
enough to get all my 26 jobs running at the same time (as illustrated
by the graphing of the Falkon log that Ioan showed me).
- there are some other throttling parameters in
$VDS_HOME/etc/swift.properties (which I also set to 30)
The general observation is that I needed to modify the scheduler.xml
config file, and I need to set larger throttle values that the limit
of workers requested.
In the current scheme (simply add Falkon to Swift as a provider) the
Swift scheduler (the weighted site selection algorithm) adversely
influences the optimal execution of the workflow.
There might be other parameters to work with, but my opinion is that
we should use a different (non-throttling) scheduler in combination
with Falkon
Tibi
On 6/21/07, Mike Wilde <a class="moz-txt-link-rfc2396E" href="mailto:wilde@mcs.anl.gov"><wilde@mcs.anl.gov></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Ive had the same question - it seems that throttling is also problematic
for
Tibi in the econ workflow.
Tibi, since you have looked pretty deeply into it, could you write up a
desription on how the algorithm works and how the parameters affect it.
Mihael, when you are back on central time next week, could you work with
TIbi on
this? If its not already, this should be part of the Swift documentation.
Then we should work on getting high-performance settings for the different
runtime environments we use, in particular Falkon as Ian asks.
- Mike
Ian Foster wrote, On 6/21/2007 6:50 AM:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,
I don't fully understand how throttling works in Swift/Karajan. However,
I understand that even when using Falkon, we may be doing some
throttling. Is there a reason to do that in this case, given that Falkon
can maintain large numbers of tasks just fine?
I ask this because in a recent MolDyn run, there seemed to be some
uncertainty as to whether throttling was slowing down job dispatch. If
we could turn it off altogether, that question would presumably go away.
Ian.
</pre>
</blockquote>
<pre wrap="">--
Mike Wilde
Computation Institute, University of Chicago
Math & Computer Science Division
Argonne National Laboratory
Argonne, IL 60439 USA
tel 630-252-7497 fax 630-252-1997
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
<pre wrap=""><!---->
</pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Ian Foster, Director, Computation Institute
Argonne National Laboratory & University of Chicago
Argonne: MCS/221, 9700 S. Cass Ave, Argonne, IL 60439
Chicago: Rm 405, 5640 S. Ellis Ave, Chicago, IL 60637
Tel: +1 630 252 4619. Web: <a class="moz-txt-link-abbreviated" href="http://www.ci.uchicago.edu">www.ci.uchicago.edu</a>.
Globus Alliance: <a class="moz-txt-link-abbreviated" href="http://www.globus.org">www.globus.org</a>.
</pre>
</body>
</html>