NorduGrid comments on the GGF Usage Record draft document
(see [1] for contacts).


Background
==========

The NorduGrid Collaboration [1] develops & maintains the Advanced
Resource Connector (ARC) Grid middleware. The middleware is being used
in production in numerous Grids. The ARC middleware is equipped with a
logging service, the "logger" collects and stores job records for
logging and accounting purposes.  In the logger service each job is
represented by a record, the so-called "nordugrid usage record". The
NorduGrid usage record schema was designed to be used with the ARC
middleware for storing usage & accounting information of jobs that are
run on sites that have installed the ARC middleware.  The NorduGrid UR
is currently being revised with the coming new release of the ARC
middleware. Please consult [2] for more information about the ARC
logger.


General observations
====================

- The document represents a long-awaited attempt at standardization of
resource usage records. We look forward to implement the format that
will be agreed by the GGF participants. Still, much work has to be
done in order to deliver an unambiguous specification that suits
everybody and accommodates most important aspects.

- The document does not give a clear definition of the "usage record",
which leads to rather confusing statements such as "Record identity
uniquely defines a record in the usage record" (page 6, definition of
RecordIdentity).

Furthermore, when talking about the logging & accounting information
associated to grid jobs it is crucial to give some kind of definition
of a grid job. Many of the UR properties described in the document are
ambiguous because it is not clear what constitutes a grid job.  An
example is StarTime. Is the brokering or stagein phase of a grid job
taken into account?


- The document states that "its main purpose is to outline the basic
building blocks of the accounting record"

NorduGrid agrees with this scope, we consider the UR rather as a
logging and accounting record of a grid job rather than simply a
record of resource consumption. For us the UR should contain
information not just about resource consumption but also about job
identity, ownership, status, etc. Maybe it would make sense to rename
the UR as logging or accounting record?


- Many of the attributes are inadequately defined or their meaning is
deliberately left open. This partly defeats the purpose of the schema
since it was designed specifically to be a format for exchanging usage
data over grids but if interpretations of the attributes are different
at different sites/grids, comparing exchanged data becomes
complicated.  For example the Charge, Status, StartTime, EndTime, base
properties claim that "The meaning of this charge will be site
dependent", "the semantic meaning of the status is site dependent" or
"the value of this property may depend on the queuing system", etc.


- The GGF UR proposal is still too 'site' or batch system specific; in
many places the document assumes data exchange among computing centers (sites) and not among Grids. Seems that the grid 
layer is not really
taken into account, the UR at many places resembles as a data exchange
format between batch systems (or sites) and not Grids. For example,
the Current Practices Survey (Appendix A) covers only supercomputing
centers and not a single Grid.  The UR document should make it clear
it is a Grid UR proposal, enabling grid job logging & accounting data
exchange between different Grids.


- The document states: "The document does not attempt to dictate the
format in which the accounting records are stored at a local site,
instead it meant to be a common exchange format"

NorduGrid fully supports this approach (we assume "Grid" everywhere we
read "site"), we consider the UR as an exchange format between
Grids. This implies that the GGF UR should be powerful enough to
"accommodate" other Grid/local Usage Records. Later in these comments,
a mapping of the...