[OGSA-D-WG] Definition of data consistency [RESEND]

[Dave Berry]

[As my first attempt got flagged as spam, I'm resending this]

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