[drmaa-wg] Session Required?

[Rajic, Hrabri]

100% agree.  To reach the DRM system particular functionality via native
specification or job categories job attribute require an established
session.
The request primarily comes when there are possibilities to choose a
particular implementation when two or more are available.

Even when using different contact strings within the same DRMAA
implementation, that interface to different DRMS versions would need
established session to properly evaluate DRMS dependent attributes.
Lack of DRMAA_ERRNO_NO_ACTIVE_SESSION error code in the job attribute
routines appears as a minor hole in the language independent spec.

It is ironic that DRM system independent spec such as DRMAA needs DRMS
or session info to construct a job template or job request.

    -Hrabri
 

-----Original Message-----
From: owner-drmaa-wg at ggf.org [mailto:owner-drmaa-wg at ggf.org] On Behalf
Of Daniel Templeton
Sent: Friday, January 14, 2005 10:07 AM
Cc: DRMAA Working Group
Subject: Re: [drmaa-wg] Session Required?

Rajic, Hrabri wrote:

> We could question if DRMAA_ERRNO_DRM_COMMUNICATION_FAILURE error code
> for job template allocation/deallocation implies
> DRMAA_ERRNO_NO_ACTIVE_SESSION error is also needed.  While the former
> error is reasonable and allows certain degree of flexibility in
> implementations the latter is very likely to not be needed.
> From C language standpoint both of the above codes are not necessary,
> i.e. job attributes objects should exist outside sessions and DRM run
> times.
> 
> A better question would be is there a DRM system that requires a
session
> before jt could be created that we need to support.  

This is exactly the question.  Are we supporting the creation of job 
templates outside of the context of a session?  I would vote, no.  The 
reason is that for the SGE implementation of the drmaa_transfer_files 
attribute, the DRMS has to be asked whether file staging is enabled or 
not.  Until we're bound to a DRMS, we can't ask.
I can also imagine situations where the default settings or behavior of 
a job template may be determine by the DRMS instance to which you're 
connected.

> My recollection is failing me of we intended things to be as they are.

It's probably also worth noting that the DRMAA_ERRNO_NO_ACTIVE_SESSION 
error code is missing from every routine except drmaa_exit() in the 
language independent spec.

> In OO languages that could depend on the classes organization.  If jt
> object belongs to a session object it might require established
session
> because of its hosting object.  Using the above analysis I would argue
> that there is no need for DRMAA_ERRNO_NO_ACTIVE_SESSION errors to be
> returned by jt methods.
> 
> Could you clarify things Dan?

In the Java binding, there are now two ways to get a JobTemplate.  One 
is to ask the Session for it, and the other is to create it directly 
using its constructor, which carries the warning that the Session may 
reject it since it didn't come from the Session.

>     -Hrabri
>  
> 
> -----Original Message-----
> From: owner-drmaa-wg at ggf.org [mailto:owner-drmaa-wg at ggf.org] On Behalf
> Of Andreas Haas
> Sent: Friday, January 14, 2005 6:50 AM
> To: DRMAA Working Group
> Subject: Re: [drmaa-wg] Session Required?
> 
> On Fri, 14 Jan 2005, Daniel Templeton wrote:
> 
> 
>>I'm in the job template section of the C binding now, and I noticed
> 
> that
> 
>>none of the functions there return DRMAA_ERRNO_NO_ACTIVE_SESSION.  Is
>>that intentional?  If so, I need to fix the Java language binding
> 
> spec.
> 
> I believe it is not intensional.
> 
> With C binding in mind one one could argue it is unlikely a session
> is needed before those functions can be used. But Java binding clearly
> indicates those C functions must be allowed to return
> DRMAA_ERRNO_NO_ACTIVE_SESSION.
> 
> Regards,
> Andreas
>