[saga-rg] Jobs and SandBoxing

[Andre Merzky]

Sorry Chris, late answer...


Quoting [Christopher Smith] (Aug 04 2005):
> 
> On 29/7/05 10:47, "Andre Merzky" <andre at merzky.net> wrote:
> 
> > Another comment I got about jobs in SAGA is: how is
> > sandboxing supported?  Can I at least determine if my
> > job runs in a sandbox?  Or at least what it's 'cwd' is?
> 
> You can specify the job's CWD as submission time, but
> there is no attribute to retrieve to fill in this
> information. Perhaps it should be added to the JobInfo
> class? 

Yes, perhaps.  I think the basic use case is:

 - you run a job
 - job write data file ./out.dat
 - job finishes
 - you want to retrieve the data file

w/o knowing the cwd, you have trouble finding the file.
Setting it beforehand does not help if the scheduler creates
a sandbox.

So adding that info to the jobinfo seems to make sense.


> As for supporting sandboxes, what does that actually mean?
> In a chroot jail?  With a restricted user id (whatever
> that means)? Why should I care? What's the use case? 

I guess you are right: sandbox is by definition transparent
to the end user, isn't it?  So while it might be useful to
know where your job runs (see above), it may no make sense
to enforce sandboxing (either its used or it isn't - what
can SAGA do about this? nothing).  


> > Does a job have a unique job ID I can use to identify
> > it?  (That question is related to the session
> > persistency discussed in another thread I think).
> 
> There is a getJobId method on the Job interface for this
> purpose. It's up to the backend to provide the ID, so
> uniqueness is not something SAGA can guarantee.

I semi-agree.  For finding your job again, you need more
then the backend job-id - you need also the contact point
for the backend.  Your SAGA implementation might know about
that, so it may be able to create a 'better' job id.

In GAT, we did that, and had the distinction between a
Native-JobID (the backends), and GAT-JobID (globally
unique).  That might be overkill to mandate for SAGA at this
point, unless we have a clear use case wanting so I guess.

So, bottom line, I guess you are right, backend-id should be
sufficient unless we run into problems with that.

Thanks, Andre.

>   
> -- Chris



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