Re: Starcluster - Taking advantage of multiple cores on EC2

From: Rayson Ho <no email>
Date: Wed, 31 Aug 2011 11:33:19 -0700 (PDT)

OK, so with MKL 10.x, even if OMP_NUM_THREADS is undefined, the library will automatically create threads to take advantage of all the cores. You might want to check the MKL version of your EC2 nodes, and also set the env.var. OMP_NUM_THREADS to 8 and see if your app is using more cores.

http://software.intel.com/en-us/articles/intel-math-kernel-library-intel-mkl-intel-mkl-100-threading/#1

(I don't believe it is anything else other than some application settings or version that is different on EC2. In the end, an EC2 VM is pretty much the same thing from the application point of view as a real machine.)

Rayson

=================================
Grid Engine / Open Grid Scheduler
http://gridscheduler.sourceforge.net


--- On Wed, 8/31/11, Bill Lennon <blennon_at_shopzilla.com> wrote:
> processor   
>    : 0
> processor       : 1
> processor       : 2
> processor       : 3
> processor       : 4
> processor       : 5
> processor       : 6
> processor       : 7
>
> -----Original Message-----
> From: Rayson Ho [mailto:raysonlogin_at_yahoo.com]
>
> Sent: Wednesday, August 31, 2011 11:23 AM
> To: starcluster_at_mit.edu;
> Bill Lennon
> Subject: RE: [StarCluster] Starcluster - Taking advantage
> of multiple cores on EC2
>
> --- On Wed, 8/31/11, Bill Lennon <blennon_at_shopzilla.com>
> wrote:
> > When I run my app interactively outside of sge and
> look at htop it
> > only uses one core :(
>
> OK, so at least we are not dealing with SGE... Looks like
> an OS/app issue now :-D
>
> From the shell, run:
>
> % cat /proc/cpuinfo
>
> or:
>
> % cat /proc/cpuinfo|grep processor
>
> This should at least tell us the number of cores/threads on
> the EC2 node.
>
> Rayson
>
> =================================
> Grid Engine / Open Grid Scheduler
> http://gridscheduler.sourceforge.net

>
>
> >
> > In my original message I tried to explain that I
> launched the
> > starcluster ami on a single ec2 instance, so I'm not
> working with a
> > cluster.  But I'd still like to take advantage of all
> the cores.
> >
> > -----Original Message-----
> > From: Rayson Ho [mailto:raysonlogin_at_yahoo.com]
> >
> > Sent: Wednesday, August 31, 2011 11:09 AM
> > To: starcluster_at_mit.edu;
> > Bill Lennon
> > Subject: RE: [StarCluster] Starcluster - Taking
> advantage of multiple
> > cores on EC2
> >
> > --- On Wed, 8/31/11, Bill Lennon <blennon_at_shopzilla.com>
> > wrote:
> > > 1) What do you get when you run "qhost" on the
> EC2
> > cluster??
> > >
> > > error: commlib error: got select error
> (Connection
> > > refused)
> > > error: unable to send message to qmaster using
> port
> > 6444 on host
> > > "localhost": got send error
> >
> >
> > Looks like you are not able to connect to the SGE
> qmaster... did you
> > actually submit jobs to SGE??
> >
> >
> > > 2) If you run your application outside of SGE on
> your
> > EC2 cluster, do
> > > you get the same behavior??
> > >
> > > If I 'python job.py' I don't see those
> errors...if
> > that's what your
> > > asking?
> >
> >
> > I mean, on one of your EC2 nodes, run your application
> interactively.
> > Then run "top" or "uptime" and see if outside of SGE,
> your application
> > is able to use all the cores on the node.
> >
> > Rayson
> >
> > =================================
> > Grid Engine / Open Grid Scheduler
> > http://gridscheduler.sourceforge.net

>
> >
> >
> >
> > >
> > > 3) Intel MKL uses OpenMP internally, did you set
> the
> > env.
> > > var. OMP_NUM_THREADS on the laptop??
> > >
> > > Nope.
> > >
> > > Hope that may give you a lead.  I'm
> unfortunately a
> > noob.
> > >
> > > -----Original Message-----
> > > From: Rayson Ho [mailto:raysonlogin_at_yahoo.com]
> > >
> > > Sent: Wednesday, August 31, 2011 10:57 AM
> > > To: Bill Lennon; starcluster_at_mit.edu
> > > Subject: Re: [StarCluster] Starcluster - Taking
> > advantage of multiple
> > > cores on EC2
> > >
> > > Bill,
> > >
> > > 1) What do you get when you run "qhost" on the
> EC2
> > cluster??
> > >
> > > 2) If you run your application outside of SGE on
> your
> > EC2 cluster, do
> > > you get the same behavior??
> > >
> > > 3) Intel MKL uses OpenMP internally, did you set
> the
> > env.
> > > var. OMP_NUM_THREADS on the laptop??
> > >
> > > Rayson
> > >
> > > =================================
> > > Grid Engine / Open Grid Scheduler
> > > http://gridscheduler.sourceforge.net

>
> >
> > >
> > >
> > >
> > > --- On Wed, 8/31/11, Chris Dagdigian <dag_at_bioteam.net>
> > > wrote:
> > > > Grid Engine just executes jobs and manages
> > resources.
> > > >
> > > > It's up to your code to use more than one
> core.
> > > >
> > > > Maybe there is a config difference between
> your
> > local
> > > scipy/numpy etc.
> > > > install and how StarCluster deploys it's
> > version?
> > > >
> > > > Grid Engine assumes by default a  1:1
> ratio
> > between
> > > job and CPU core
> > > > unless you are explicitly submitting to a
> > parallel
> > > environment.
> > > >
> > > > If you are the only user on a small cluster
> you
> > > probably don't have to
> > > > do much, the worst that could happen would
> be
> > that SGE
> > > queues up and
> > > > runs more than one of your threaded app job
> on
> > the
> > > same host and they
> > > > end up competing for CPU/memory resources to
> the
> > > detriment of all.
> > > >
> > > > One way around that would be to configure
> > exclusive
> > > job access and
> > > > submit your job with the "exclusive"
> request.
> > That
> > > will ensure that
> > > > your job when it runs will get an entire
> > execution
> > > host.
> > > >
> > > > Another way is to fake up a parallel
> environment.
> > For
> > > your situation
> > > > it is very common for people to build a
> parallel
> > > environment called
> > > > "Threaded" or "SMP" so that they can run
> threaded
> > apps
> > > without
> > > > oversubscribing an execution host.
> > > >
> > > > With a threaded PE set up you'd submit your
> job:
> > > >
> > > >   $ qsub -pe threaded=<# CPU>
> > my-job-script.sh
> > > >
> > > > ... and SGE would account for your single
> job
> > using
> > > more than one CPU
> > > > on a single host.
> > > >
> > > >
> > > > FYI Grid Engine has recently picked up some
> Linux
> > core
> > > binding
> > > > enhancements that make it easier to pin jobs
> and
> > tasks
> > > to specific
> > > > cores. I'm not sure if the version of GE
> that is
> > built
> > > into
> > > > StarCluster today has those features yet but
> it
> > should
> > > gain them
> > > > eventually.
> > > >
> > > > Regards,
> > > > Chris
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Bill Lennon wrote:
> > > > > Dear Starcluster Gurus,
> > > > >
> > > > > I’ve successfully loaded the
> Starcluster
> > AMI
> > > onto a
> > > > single high-memory
> > > > > quadruple extra large instance and am
> > performing
> > > an
> > > > SVD on a large
> > > > > sparse matrix and then performing
> k-means on
> > the
> > > > result.  However, I’m
> > > > > only taking advantage of one core when
> I do
> > > > this?  On my laptop (using
> > > > > scipy numpy, intel MKL), on a small
> version
> > of
> > > this,
> > > > all cores are taken
> > > > > advantage of automagically.  Is there
> an
> > easy
> > > way
> > > > to do this with a
> > > > > single starcluster instance with Atlas?
> Or
> > do I
> > > need
> > > > to explicitly write
> > > > > my code to multithread?
> > > > >
> > > > > My thanks,
> > > > >
> > > > > Bill
> > > > >
> > > >
> _______________________________________________
> > > > StarCluster mailing list
> > > > StarCluster_at_mit.edu
> > > > http://mailman.mit.edu/mailman/listinfo/starcluster

>
> >
> > > >
> > >
> > >
> >
> >
>
>
Received on Wed Aug 31 2011 - 14:33:22 EDT