[saga-rg] JobService.submitJob() query

[Andre Merzky]

Hi Chris, 

Quoting [Christopher Smith] (Mar 07 2006):
> 
> run_job doesn't have an RM contact, but is actually specifying the end
> resource to run on (a FQDN of a compute node). It's there mostly to support
> things like ssh backends.

For SSH or GRAM, what would be the difference between a
"resource management contact" and a the "end resource"?
Would there be any difference?

If the "RM contact" is "my_rm://rm.grid.net:123/", what does the
"end resource" be used for: as a hint for the RM where to
run on?

Thanks, Andre.


> 
> -- Chris
> 
> 
> On 6/3/06 13:59, "Andre Merzky" <andre at merzky.net> wrote:
> 
> > Hi Chris, Graeme,
> > 
> > if we go for 2, we should actually remove the RM contact
> > from run_job, as that would conflict with the RM contact
> > given on the job_service creation.
> > 
> > Cheers, Andre.
> > 
> > 
> > Quoting [Christopher Smith] (Mar 06 2006):
> >> 
> >> I'll finally provide some context first ....
> >> 
> >> As Andre mentioned in a previous email, we had left the choice of resource
> >> manager up to the implementation of the library, and didn't expose it up
> >> into the API layer. Feedback indicates that this was a mistake. :-)
> >> 
> >> I can go for either 1 or 2, with a preference for 2. The reason is that to
> >> me the JobService represents the service endpoint to a job scheduler or
> >> resource manager. That said, I'm not religious about it.
> >> 
> >> -- Chris
> >> 
> >> 
> >> On 22/2/06 01:27, "Graeme Pound" <G.E.POUND at soton.ac.uk> wrote:
> >> 
> >>> Andre,
> >>> 
> >>> I may have confused the issue by mentioning the JobDefinition attribute
> >>> "SAGA_HostList". This appears to have a valid role mapping to the
> >>> "CandidateHosts" element of a JSDL document (and also in LSF?). The
> >>> "SAGA_HostList" attribute should not be used to specify the resource
> >>> manager.
> >>> 
> >>> The problem rather is how is the resource manager (in the form of a URL
> >>> or machine name) specified when the user invokes submitJob(). There are
> >>> three possible solutions:
> >>> 1) Add an argument "host" to the submitJob() method (similar to
> >>> runJob()) to specify the resource manager
> >>> 2) Specify the resource manager in the JobService constructor
> >>> 3) Add a new required attribute to the JobDefinition class (e.g.
> >>> "SAGA_ResouceManager")
> >>> 
> >>> I do not like solution 3 since job definition is conceptually distinct
> >>> from the choice of resource manager, for example you may wish to define
> >>> a single JobDefinition and submit that job to several different resource
> >>> managers.
> >>> 
> >>> I do not have a strong preference between solutions 1 and 2. (Although
> >>> constructors pose a small problem for the Java bindings)
> >>> 
> >>> Graeme
> >>> 
> >>> 
> >>> 
> >>> Andre Merzky wrote:
> >>>> Hi Graeme, 
> >>>> 
> >>>> I am not much of an expert in resource thingies, so what I
> >>>> say should be taken with a grain of salt.  Or rather with a
> >>>> spoon I guess...
> >>>> 
> >>>> I assumed that run_job ("myhost", ...) would run the job on
> >>>> myhost.  But what you say (and what the spec implies I
> >>>> think, after reading again) is that myhost is specifying the
> >>>> resource manager contact, not the target host.  Right?
> >>>> 
> >>>> Well, then we have the ability to specify a resource manager
> >>>> contact for run_job, and a target resource on job_submit.
> >>>> But no combination seems possible.
> >>>> 
> >>>> Frankly, I think that does not make sense.  For one the
> >>>> semantics between job_run and job_submit should not be that
> >>>> different (job_run was supposed to be a shortcut for
> >>>> job_submit).  Secondly, there are clearly use cases for both
> >>>> versions (resource manager contact and target resource).
> >>>> 
> >>>> One solution would be to specify the resource manager
> >>>> contact in the constructor of the job_service, as that is
> >>>> supposed to represent the resource and job manager anyway I
> >>>> guess.  The host in run_job would then specify the target
> >>>> resource ("" for 'any resource' I guess).
> >>>> 
> >>>> But again, I am not on firm ground in resource management,
> >>>> and rather would not like to mess w/o feedback of someone
> >>>> more knowledgeable.  What is your opinion?
> >>>> 
> >>>> Thanks, Andre.
> >>>> 
> >>>> 
> >>>> 
> >>>> Quoting [Graeme Pound] (Feb 21 2006):
> >>>>> Andre,
> >>>>> 
> >>>>> I do not think that the attribute 'SAGA_HostList' of
> >>>>> JobDefinition is appropriate either. The description of
> >>>>> 'SAGA_HostList' in the strawman API reads:
> >>>>> 
> >>>>>   SAGA_HostList
> >>>>>    - A list of host names, or host group names, which can be
> >>>>>      considered by the resource manager as candidate hosts for
> >>>>>      the job. Whether or not the job actually ends up running
> >>>>>      on one of the hosts in the list, is solely at the
> >>>>>      discretion of the resource manager. Vector of strings.
> >>>>>      (JSDL, LSF)
> >>>>> 
> >>>>> This attribute should be used to pass information to the
> >>>>> resource manager, NOT to specify the resource manager. For
> >>>>> example it maps to the "CandidateHosts" element of a JSDL
> >>>>> document.
> >>>>> 
> >>>>> The first argument of runJob() is the "host name or IP
> >>>>> address of the endpoint which will accept and run the
> >>>>> job". This argument is not defined for submitJob(), nor is
> >>>>> it defined as an attribute of JobDefinition.
> >>>>> 
> >>>>> Graeme
> >>>> 
> >>>>> 
> >>>>> Andre Merzky wrote:
> >>>>>> Oops, you are right!  My wrong - mixed it up with
> >>>>>> ExecutionHosts.  Well, then I really was off target:
> >>>>>> SAGA_HostList is then indeed what you should use to specify
> >>>>>> the target resource.
> >>>>>> 
> >>>>>> The run_job would, in its simpliest implementation, create a
> >>>>>> job description with SAGA_HostList set to the specified
> >>>>>> endpoint, and do a submit_job on that description.
> >>>>>> 
> >>>>>> Sorry for creating confusion...
> >>>>>> 
> >>>>>> Andre.
> >>>>>> 
> >>>>>> 
> >>>>>> Quoting [Graeme Pound] (Feb 20 2006):
> >>>>>>> Date: Mon, 20 Feb 2006 16:24:32 +0000
> >>>>>>> From: Graeme Pound <G.E.POUND at soton.ac.uk>
> >>>>>>> To: Andre Merzky <andre at merzky.net>
> >>>>>>> CC: SAGA RG <saga-rg at ggf.org>
> >>>>>>> Subject: Re: [saga-rg] JobService.submitJob() query
> >>>>>>> 
> >>>>>>> Andre,
> >>>>>>> 
> >>>>>>> 
> >>>>>>>> 'SAGA_HostList' is on the job, and read only - it gives
> >>>>>>>> information on where the job _is_ running, not where it
> >>>>>>>> _should_ run.
> >>>>>>> I do not follow you here. 'SAGA_HostList' is an attribute of
> >>>>>>> JobDefinition (not JobInfo), therefore it should not be read only.
> >>>>>>> 
> >>>>>>> Graeme
> >>>>>>> 
> >>>>>>> 
> >>>>>>> Andre Merzky wrote:
> >>>>>>>> Uhm, I think you got us there.  I don't see any way to
> >>>>>>>> specify the resource either, so its left completely up to
> >>>>>>>> the backend to schedule the job.  I am not sure if that was
> >>>>>>>> intended.
> >>>>>>>> 
> >>>>>>>> Chris, are we missing something?  Did we intend to leave
> >>>>>>>> resource specification out?  Can't really be, as we have it
> >>>>>>>> in run_job as Graeme points out...
> >>>>>>>> 
> >>>>>>>> 'SAGA_HostList' is on the job, and read only - it gives
> >>>>>>>> information on where the job _is_ running, not where it
> >>>>>>>> _should_ run.
> >>>>>>>> 
> >>>>>>>> Andre.
> >>>>>>>> 
> >>>>>>>> 
> >>>>>>>> Quoting [Graeme Pound] (Feb 20 2006):
> >>>>>>>>> Hi,
> >>>>>>>>> 
> >>>>>>>>> Can anybody clear up this issue for me? I may be missing something in
> >>>>>>>>> the spec.
> >>>>>>>>> 
> >>>>>>>>> Thanks,
> >>>>>>>>> Graeme
> >>>>>>>>> 
> >>>>>>>>> 
> >>>>>>>>> -3.31 How is the resource manager endpoint for JobService.submitJob()
> >>>>>>>>> specified?
> >>>>>>>>> 
> >>>>>>>>> The endpoint is specified by an argument of JobService.runJob(), but
> >>>>>>>>> is
> >>>>>>>>> not _obvious_ for submitJob(). Is the endpoint a property of the
> >>>>>>>>> instance of JobService (with runJob() a 'static' method of the class),
> >>>>>>>>> or is the endpoint specified as an attribute of JobDefinition?
> >>>>>>>>> 
> >>>>>>>>> I assume that the contents of the JobDefinition attribute
> >>>>>>>>> 'SAGA_HostList' is intended to be passed to the resource manager
> >>>>>>>>> (rather than specify the resource manager itself); for example mapping
> >>>>>>>>> to the 'CandidateHosts' element of a JSDL document. Is an additional
> >>>>>>>>> attribute within JobDefinition required to specify the endpoint?
> >>>>>>>> 
> >>>>>> 
> >>>>>> 
> >>>> 
> >>>> 
> >>>> 
> >>> 
> > 
> > 



-- 
"So much time, so little to do..."  -- Garfield