On May 28, 2020, at 11:44 AM, Chaarawi, Mohamad via IO-500 <io-500(a)vi4io.org>
wrote:
Hi John (and rest of IO-500 committee),
On a different note, could you please shed some light on the committee’s decision to
require 2 “apps” to run the benchmark and not just one?
It seems this change has been announced very close to the deadline and the C-app appears
to be broken currently for non-POSIX backends (mainly ones that require extra options that
are not IOR generic). Maybe I missed an earlier notification, and excuse me if I did. But
if not, I just feel that a requirement like that should be made right after the conference
for the next submission deadline, and not so close to the deadline where people may have
already have results to submit using the io-500-dev repo and not the new io500-app one.
Mohamad,
the motivation for running two copies of the benchmark and not only one is that
we want to move forward with using the io500 C-app vs the bash script because:
- the existing io500.sh script had caused problems for some sites, because
it is "launching" the various ior/mdtest runs itself via mpirun, rather
than being the executable itself
- parsing results from the mdtest/ior output to generate the scores was itself
fragile, and prone to error if the output was slightly different
Running the C-app and bash script overlapping for ISC'20 allows us to compare
the results across multiple different systems, to ensure that the two produce
equivalent results, and to ensure that the C-app is working correctly across
different environments. Having the bash script results available in case
of issues or discrepancies between the two is important to ensure continuity.
The C-app has been in development for some time, but has not had much feedback.
Making it part of the ISC'20 submission for everyone ensures there is enough
testing before we do a complete changeover to the C-app for SC'20.
Cheers, Andreas(*)
* These statements merely reflect my own personal view; the only mechanism for
announcing official IO500 policies and decisions is the committee(a)io500.org
email address
From: IO-500 <io-500-bounces(a)vi4io.org> on behalf of John Bent
via IO-500 <io-500(a)vi4io.org>
Reply-To: John Bent <johnbent(a)gmail.com>
Date: Thursday, May 28, 2020 at 12:25 PM
To: Mark Nelson <mnelson(a)redhat.com>
Cc: "io-500(a)vi4io.org" <io-500(a)vi4io.org>
Subject: Re: [IO-500] Some rules clarifications?
Mark and all,
The committee just added a rule clarifying precreation of directories to the rules page:
https://www.vi4io.org/io500/rules/submission. The newly added rule states:
"Each of the four main phases (IOR easy and hard, and mdtest easy and hard) has a
subdirectory which can be precreated and tuned (e.g. using tools such as lfs_setstripe or
beegfs_ctl); however, additional subdirectories within these subdirectories cannot be
precreated."
Below my signature, I am including my standard disclaimer that my email is not
necessarily an official IO500 position but note that the rules page itself is. :)
Hope this is clear; please do reply with any questions or need for further
clarification,
Thanks,
John(*)
* These statements merely reflect my own personal view; the only mechanism for announcing
official IO500 policies and decisions is the committee(a)io500.orgemail address.
On Wed, May 27, 2020 at 5:14 PM John Bent <johnbent(a)gmail.com> wrote:
> Hey Mark,
>
> Thanks for the interest. It will be great to get your contributions!
>
> 1. Must be exactly 300 seconds.
> 2. Does not include the directories. Other historical submissions have tuned the
directories exactly as you describe.
> 3. Yes, 10+ metal nodes in AWS satisfies this requirement.
>
> Other committee members, and community members, please chime in if I got anything
wrong! Mark, you might note the disclaimer below my signature which is just our
committee's way of being careful. I'll make sure to discuss this email with the
rest of the committee and will let you know if any of my answers need official
clarification.
>
> Thanks,
>
> John(*)
>
> * These statements merely reflect my own personal view; the only mechanism for
announcing official IO500 policies and decisions is the committee(a)io500.orgemail address.
>
>
> On Wed, May 27, 2020 at 4:44 PM Mark Nelson via IO-500 <io-500(a)vi4io.org>
wrote:
>> Hi Folks,
>>
>>
>> We are thinking about throwing together some cephfs io500 results for
>> ISC20 and I just wanted to make sure that we are doing the right thing
>> in a couple of cases. Any help would be much appreciated since we've
>> never submitted results before. We might have a couple of additional
>> questions later on, but for now:
>>
>>
>> 1) "All create/write phases must run for at least 300 seconds; the
>> stonewall flag must be set to 300 which should ensure this."
>>
>> Is it acceptable to set the stonewall higher than 300, or is a setting
>> of exactly 300 required?
>>
>>
>> 2) "The file names for the mdtest output files may not be
pre-created."
>>
>> Does this also include the directories? We have the ability to pin
>> directories to specific MDSes that helps in the easy tests. We also have
>> an experimental feature that more or less does this psuedo-randomly
>> behind the scenes so long as a top level xattr is set, but it would be
>> convenient if we could just pre-create the mdtest directories and set
>> the xattr to pin them individually in the "directory setup" phase of
the
>> test if allowed. Likewise, we have code that allows users to provide a
>> hint if a specific directory is expected to have lots of files which can
>> improve performance in the hard tests. I would like to pre-create the
>> mdtest directory so that we can set the xattr informing ceph that we
>> expect a lot of files to be written in that directory.
>>
>>
>> 3) "Only submissions using at least 10 physical client nodes are
>> eligible to win IO500 awards and at least one benchmark process must run
>> on each."
>>
>> We are planning on running on AWS. So long as we are using 10+ metal
>> nodes does that meet the requirement to have "at least 10 physical
>> client nodes"?
>>
>>
>> Thanks,
>>
>> Mark
>>
>> _______________________________________________
>> IO-500 mailing list
>> IO-500(a)vi4io.org
>>
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Cheers, Andreas