Sent: 09 October 2007 17:50
To: ogsa-d-wg@ggf.org
Subject: [OGSA-D-WG] Fw: Definition of data consistency
Please see Jem's note below - he can not post to this DL.
I think
that his suggestion is a good one.
Allen Luniewski
IBM Cross Brand
Services
IBM Silicon Valley Laboratory
555 Bailey Ave.
San Jose, CA
95141
408-463-2255
408-930-1844 (mobile)
----- Forwarded by Allen Luniewski/Almaden/IBM on 10/09/2007 09:49 AM
-----
10/09/2007 09:40 AM |
|
Allen/Dave, I can’t mail the data mailing list, so please feel free to pass this on if you think it’s worthwhile.
I agree with Allen about sounding specific, and this is a hard thing to turn into a direct definition without using some term such as “indication.” You might think about using an indirect form:
- Data consistency: An instance of data
is said to be “consistent” with one or more other instances of that data
if it is up-to-date with respect to those instances.
That may be enough, but you could also add something like:
- In a given system a policy may define
the rules for determining whether data is up-to-date, and for maintaining
consistency.
- Jem
Jem Treadwell
Software Engineer
HP ESS Software
856.638.6021 office | 856.638.6190 fax |
jem.treadwell@hp.com
6000 Irwin Road | Mount Laurel | NJ 08054
http://www.hp.com/go/vse
Sent: Monday, October 08, 2007 5:20 PM
To: Dave Berry
Cc: Treadwell, Jem; ogsa-d-wg@ogf.org
Subject: Re: [OGSA-D-WG] ***SPAM*** Definition of data consistency
Dave,
I think that I am okay with that
suggested change. I am a little bit worried about using the word "measure" as
it can be taken to imply things that we really do not want to address (e.g., a
means to measure and a quantifiable scale for measurement). I thought about
suggesting changing "A measure" to "An indication" but that seems just a bit
too vague to me. I don't have a better suggestion right now.
Allen
Luniewski
IBM Cross Brand Services
IBM Silicon Valley Laboratory
555
Bailey Ave.
San Jose, CA 95141
408-463-2255
408-930-1844
(mobile)"Dave
Berry" <daveb@nesc.ac.uk>
Sent by: ogsa-d-wg-bounces@ogf.org 10/08/2007 02:11 PM |
|
Jem queried our definition of data consistency, which is currently:
| A policy that specifies or describes how up-to-date an instance of data is in one service of a distributed system, with respect to one or more instances of that data elsewhere in the system. |
Jem said (in e-mail):
my thought was that data consistency would be a state of the data - it's consistent w.r.t. some other set of data or it isn't; the policy would be the rules that determine whether it is, and what the requirements are.
I've had a look through our document and I agree.
We refer to data consistency policies but also to data consistency
requirements, mechanisms and strategies.
So, how about this as a
revised definntion:
"A measure of how up-to-date an instance of data is
in one service of a distributed system, with respect to one or more instances
of that data elsewhere in the system."
Best wishes,
Dave Berry
Deputy Director,
Research & E-infrastructure Development
National e-Science Centre
15 South College Street, Edinburgh, EH8 9AA
+44 131 651 4039 www.nesc.ac.uk
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