[saga-rg] JobService.submitJob() query

[Christopher Smith]

Ultimately the host specified in run_job turns into the SAGA_Hostlist
attribute with only the one name specified.

Yes ... I suppose the RM endpoint is needed somewhere for run_job, but then
it's starting to get more complicated, and thus you have to start
questioning whether it's needed ...... etc, etc

-- Chris



On 6/3/06 15:15, "Andre Merzky" <andre at merzky.net> wrote:

> 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?
>>>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>> 
>>> 
>>> 
> 
>