AW: [GE users] resource allocation and race condition

Charu Chaubal Charu.Chaubal at Sun.COM
Fri Oct 15 16:21:04 BST 2004


    [ The following text is in the "ISO-8859-1" character set. ]
    [ Your display is set for the "ISO-8859-10" character set.  ]
    [ Some special characters may be displayed incorrectly. ]

Hello,

Please see this HOWTO on tracking licenses with GE:
http://bioteam.net/dag/sge-flexlm-integration/

The HOWTO has all the details, but basically, you track a license with 
*both* a load sensor *and* a consumable resource simultaneously.  The 
GE master will then use whichever is the lower of the two values in 
order to avoid oversubscribing a license.  The HOWTO talks about how 
there's still the possibility of a race condition, and ways to deal 
with it.

Regards,
	Charu

On Oct 15, 2004, at 8:19 AM, Olesen, Mark wrote:

>>> Assuming that I only have a single float license 'foo', I can
>>> 'qsub -l foo=1' a job.  After a while I submit two (2) new jobs with 
>>> the
>>> same resource requirement(s). Both these jobs wait politely in the
>> queue,
>>> since the resource 'foo' is unavailable.  After the first job 
>>> finishes,
>> and
>>> the load reports get correctly updated, *both* of the jobs in the 
>>> queue
>> try
>>> to grab the 'foo' resource (almost) simultaneously.
>>> How can I circumvent such a race condition?
>>
>> Could you use a SGE consumable in addition to your load sensor? - 
>> Reuti
>
>
> Based on what I can read from host_conf(5) about 'complex_values', I'd 
> have
> to alter the load sensor so that it only tracks non-SGE license use 
> rather
> than reporting the number of licenses currently available for use.
>
> This means that the load sensor needs to distinguish between 
> applications
> that were started with/without SGE. If accomplished, this would make 
> the
> load sensor anything other than lightweight.
>
> Is there a direct way, or a backdoor, to determine how many resources 
> SGE
> believes are still free and/or have been allocated?  Perhaps this 
> could be a
> means of adjusting the load sensor values.
>
> /mark
>
> Dr. Mark Olesen
> Thermofluid Dynamics Analyst
> ArvinMeritor Light Vehicle Systems
> ArvinMeritor Emissions Technologies GmbH
> Biberbachstr. 9
> D-86154 Augsburg, GERMANY
> tel: +49 (821) 4103 - 862
> fax: +49 (821) 4103 - 7862
> Mark.Olesen at ArvinMeritor.com
>
>> -----Ursprüngliche Nachricht-----
>> Von: Reuti [mailto:reuti at staff.uni-marburg.de]
>> Gesendet: Freitag, 15. Oktober 2004 11:00
>> An: users at gridengine.sunsource.net
>> Betreff: Re: [GE users] resource allocation and race condition
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe at gridengine.sunsource.net
>> For additional commands, e-mail: users-help at gridengine.sunsource.net
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe at gridengine.sunsource.net
> For additional commands, e-mail: users-help at gridengine.sunsource.net
>
>
###############################################################
# Charu V. Chaubal				# Phone: (650) 786-7672 (x87672)
# Grid Computing Technologist	# Fax:   (650) 786-4591
# Sun Microsystems, Inc.			# Email: charu.chaubal at sun.com
###############################################################


---------------------------------------------------------------------
To unsubscribe, e-mail: users-unsubscribe at gridengine.sunsource.net
For additional commands, e-mail: users-help at gridengine.sunsource.net




More information about the gridengine-users mailing list