Hiho,
Am 12.05.2008 um 15:14 schrieb Prentice Bisbal:
At a previous job, I installed SGE for our cluster. At my current
job
Torque is the queuing system of choice. I'm very familar with
SGE, but
only have a cursory knowledge of Torque (installed it for
evaluation,
and that's it). We're about to purchase a new cluster. I'd have
to make
a good argument for using SGE over Torque. I was wondering if the
following SGE features exist in Torque:
1. Interactive shells managed by queuing system
2. Counting licenses in use (done using a contributed shell
script in
SGE)
3. Separation of roles between submit hosts, execution hosts, and
administration hosts
4. Certificate-based security.
Are there any notable features available in Torque that aren't
available
in SGE?
what you can find in Torque but not in SGE: request a mixture of
nodes,
i.e. one heavy node with much memory (or big I/O options) and 5 nodes
with less memory or less disk performance for a parallel job.
Huh? Can you elaborate? My initial thought is "why would you need
this?", but I think I see where you're going with this...
For some types of applications only the "master" of a parallel job is
collecting all the information and accessing the disk to store the
results. Therefore this, and only this, machine needs better I/O
capabilities than the slave nodes.
It's still an RFE in SGE to get any arbitrary combination of
resources, e.g. you need for one job 1 host with big I/O, 2 with huge
memory and 3 "standard" type of nodes you could request in Torque:
-l nodes=1:big_io+2:mem+3:standard
(Although this syntax has its own pitfalls: -l nodes=4:ppn=1 might
still allocate 2 or more slots on a node AFAIO in my tests.)
As Craig pointed out correctly, it can be set up in SGE, but there
might be combinatins where this gets convoluted. Thankfully I never
needed such a type of allocation of nodes, but I just wanted to point
out that this feature exists in Torque. If you don't need it for your
type of jobs, ignore it ;-)
BTW @Craig: It should be possible to request -masterq
[EMAIL PROTECTED] in 6.0 which would shorten the line.
OTOH, if you have parallel jobs:
http://www.beowulf.org/archive/2007-September/019269.html
Thanks for the link. From my understanding of SGE, you can get tight
integration with just about any MPI implementation. Is that true?
At least: all that I'm aware of. Nowadays I would go for Open MPI,
which should work out-of-the-box with both queuing systems. If you
need Linda or HP-MPI, seems SGE is the only option for a Tight
Integration (between these two - I'm not aware of the features of LSF
and others).
What is different between them from the idea: in Torque you submit
a job
into a queue, while in SGE you request resources and SGE will
select an
appropriate queue for you.
You'll have to elaborate on this, too. From my knowledge of SGE,
you had
to specify the correct queue, too, or it went into the default queue.
There is nothing like a default queue in SGE (even the all.q, defined
at installation time, is just a queue without any special features -
you can edit or remove it, if you don't like to have it in your
cluster).
If you have some queues with different limits: i.e. e.g. 1h wallclock
vs. unlimited wallclock and two queues for 8 GB vs. 16 GB, a job
requesting 2 hrs of wallclock time will for sure end up in the queue
with unlimited time constraints, while a job requesting 30 minutes
might end up in either of the two queues if a slot is free. Same
stands for memory requests: a job requesting 4 GB might end up in any
of the two memory limited queues, while a 12 GB request can only be
run in the 16 GB queue. You don't have to specify it, as SGE will
select the correct one which fulfills your requested resources.
--- Reuti
In SGE you can specify resources such as mem >= 32 GB for a node, or
arch=AMD64. You can't do this with Torque? Seems like a very basic
queuing system feature.
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