[ogsa-wg] clarification on the OGSA Job Management capability

[Sergio Andreozzi]

Dear OGSA-WG,

as part of the OMII-Europe project, I'm performing a decomposition of 
the functionalities provided by a number of Grid middlewares related to 
our project following the capabilities identified in the OGSA 1.5 document.

A problem I'm dealing with is about the Job Management service. For 
instance, in the gLite middleware, there are two main categories of 
services providing job management capability:

1. the Computing Element, that is an abstraction of a batch system 
exposing an interface to let other services to submit and manage a job; 
in the near future this component will adopt the OGSA-BES interface, but 
at the moment it is present in different flavours (GT 2 GRAM, g-Lite CE 
and CREAM)

2. the Workload Management System (WMS), that is a meta-scheduler and 
exposes an interface to let other services to submit and manages a job 
(or collection of jobs or DAGs); the WMS not only does Job Management, 
but also Execution and Planning, and Candidate Set Generator.

My doubt is the following: from the viewpoint of Job Management, are a 
meta-scheduler and a computing service semantically different or identical?

If they are identical, is it expected that in a medium future, the BES 
interface could be extendend to support the number of job types handled 
by a meta-scheduler, hence the meta-scheduler will expose the same 
interface of a computing service?

If they are not identical, what are the differences?

Thanks in advance for your comments,


Sergio Andreozzi



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Sergio Andreozzi
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