[saga-rg] JobService.submitJob() query

[Andre Merzky]

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