Hi Jon,
I'm sorry to say that I won't be able to attend the OGF meeting.
But I obviously look forward to seeing the results of the
discussions there.
I have read through the Doc and do have some comments. (I'm
obviously missing a lot since I have not attended an OGF for a
while but here goes)
General Comments:
1) w.r.t usage the ogf UR.
I don't think this is a new comment
If possible it would be ideal to ensure that the UR for storage
and the UR for compute can somehow be coupled together.
This could either mean extending the UR so it could include both
storage and compute or ensuring that both records could be
identified as having the same logical origin (site and our
group) during the same time period.
This may be achievable in the process of transforming accounting
records into billing records. So you may be able to argue it
isn't needed in the UR but is part of the machinery for
processing the URs into billing records for funding.
I just feel that if possible we should ensure that both compute
and storage URs can be correctly associated and processed
together.
Anyway the StAR may be seen as stand alone and as a practical
forerunner which could help show the way to defining a more
global UR.
2) Section 2.1.1
Although I agree with you that storage accounting is more
problematic that cpu accounting I still have the feeling that
this is partially due to the storage systems themselves.
I feel you outline why things are difficult and then with StAR
you go about defining the best way to do storage accounting with
what we have at the moment.
On our batch system (sge) I have qstat which gives me a view of
current resource usage and I have qacct which gives me the
ability to get a summarised usage over a time period based on
user/group.
At some point I'd like to see if the storage engine providers
feel that this type of functionality could be added to their
systems.
That would make the job of providing storage accounting much
simpler for us.
It may be that the providers say it's simply too much.
Specific Comments:
1) Section 2.1.2
"Identity: Describes the person or group.... " should this be
and/or can you have person,person+group,group?
2) Section 2.1.3
Allowing additional records: I know some people are against such
practices since allowing this can break standards (people put
whatever they want in and things start to get incompatible ... I
guess it's your design choice and it's up to you)
"This makes it possible to automatically remove user and group
information"
I'd suggest:
"This makes it possible to automatically remove user and group
information, a practice which may be needed for anonymization
purposes"
so I know why people may need to do this.
3) Section 2.2.2
"The specifications that are made in the following are based on
a context that the reader needs to comprehend."
I assume you mean that the following two
specifications/Definitions "A Storage Resource" and "Storage
Accounting" are used in this document and are important for it's
understanding.
I think this needs some re-wording for clarity.
4) Section 2.4.1
For the opening sentence: from the original UR doc I like the
sentence "The UsageRecord element encapsulates a single Usage
Record" And I don't mind stealing.
The term "property" is used here and at numerous other places in
the document.
I understand that this is since it's a property of your record,
however, I would suggest using the term "element" since you have
already defined the XML nature of the record and I think this
would make things a little easier to understand.
"top container property" -> "top level element of the storage
record format"
(maybe keeping the "container" is ok? "container element" ?)
5) Section 2.4.3
If you wish to follow the "property -> element" suggestion.
"The field has two attributes" -> "The RecodrIdentity element
has two attributes"
"The field is similar to the field with the same name in the
Usage Record standard" - do you need to say this?
Saying "similar" makes me start to think,"can't be used with
UR", "why not the same?"
You explicitly stated earlier that you've taken steps to make
things similar but had problems so I am not sure if you need to
say this here.
6) Section 2.4.4
"The storage system value SHOULD be constructed in such a way
that it globally identifies the storage system"
I was originally not sure if MUST would be better but I assume
you have worries about the ability of people to enforce this?
Also "globally" I think this should be accompanied with a
"uniquely".
I believe here you wish to make the recommendation that people
use a unique global name?
"globally" is not "uniquely" but I think that is what you want
and I think you use the term "global" to mean this in a few
places.
I'd suggest skimming the doc and adding unique where you mean
this to make things more clear.
7) Section 2.4.5
"StorageShare" why "Share"? This makes me think of my share of
the pie or fair share and it's a touch misleading.
I'd suggest some thought about an alternative name, but I don't
have a good suggestion "StorageSubSystem"?
8) Section 2.4.9
"DirectoryPath" We all tend to think in unix terms and at least
the storage systems that I have met have a tendency to expose
their content in these terms as well but is it really a
directory path and not a namespace path. I fear there's some
storage system out there that I didn't meet yet that doesn't
have a /abc/def/file format for displaying the data collections.
It's an optional element so this may be a moot point.
Either way I think it would be good to include a term such as
"logical namespace" within your description to clarify that it's
not physical but the storage systems logical namespace that you
are referring to.
w.r.t "the record should account for all usage in the directory
and only that directory".
do you really mean "only that dir"?
a) would this not limit it's usefulness?
If I have /atlas/data/2011 and I want a record that contains
atlas 2011 data usage I would need to sum through all subdirs
Is this what you really mean? (dir+subdirs)
b) would you allow a container that has a list of all subdirs?
e.g.
<SubDirs>
<SubDir>/atlas/data/2011/January</SubDir>
<SubDir>/atlas/data/2011/February</SubDir>
<SubDir>/atlas/data/2011/March</SubDir>
<SubDirs>
Would you consider allowing regexp in these definition (is this
possible?)
c) If you do mean "dir+subdirs" then any links which are made
within this tree could break you out and cause problems
(wrong/double accounting etc) so it would be good to be explicit
that these should be ignored.
9) Section 2.4.11
"MUST be under the SubjectIdentity" if you take my xml elements
comment from before (my 3rd comment) then this could be "MUST be
a child element of the SubjectIdentity element"
This and similar things happen a few time throughout the
document, in 2.4.12-2.4.13 etc... skim and change if you like.
10) Section 2.4.15
"GroupAttribute"
If you do use the XML context (my 3rd comment) then using the
term "Attribute" here may cause a little confusion.
So re-naming may help here (GroupProperty ?)
Additionally since you say "MUST be under the SubjectIdentity" I
would ask:
Should this be a child element of "Group" or a real XML
attribute? As you say Group needs to exist for GroupAttribute to
exist and so this would make things
easier if you ask me (more strongly defined).
These may be seen as XML style questions and looking up some XML
best practices (or asking someone who is an XML guru) may help
clear this point.
w.r.t. "The GroupAttribute property can be repeated", are there
any possible restrictions here? Could people have several
roles/subgroups and would this then lead to possible confusion
in the interpretation of the record?
I think youi may be able to argue that you just present the
information in the record and it's up to others to decide how to
interpret it (w.r.t billing etc).
11) Section 2.4.17
"ValidDuration"
To me this feels a bit artificial. I am not sure if it's needed,
how it's justified (is everyone free to make a guess at the
period of validity?).
If it's there to enable people to change accounting into billing
then I'd also suggest this is a policy issue to be discussed
between the sites providing the storage and those using the
storage.
It may be seen as a necessary measure by you but I feel a little
unsure.
If the records are indeed provided on a more frequent basis that
the duration time then it's invalidated and not needed.
The records themselves are snapshots by nature and the
interpretation of what happens in between them is open IMHO.
Even if you add a validity duration it has no meaning that the
situation wasn't completely different on the storage itself.
I think that the records are only really invalidated by a true
measure of the system state at a later time.
Any policy decisions regarding this can be made and applied
externally to the StAR itself.
I think this partially goes back to my 2nd General comment. We
can currently only get snapshots of the system state and we may
need to live with defining storage accounting based on this.
12) Section 4.1.1
I guess you already saw this but there is an "Error: Reference
source not found" when you refer to Figure1.
I would like to re-read the appendix just to make sure I
understand what you're saying there and that it's clear enough
to me.
Maybe I read it too fast the first time but I was a little
confused with some points.
There are a few places where I would have liked to suggest some
slight modification to improve the English a little.
However I didn't think that was the real aim of your request for
comments.
My English isn't perfect but I'd be willing to help out a little
here if you like.
I also want to again I'm sorry i won't be attending the OGF. I
know comments to docs like this are welcome but I also know I'm
missing a lot of the discussion and so some comments may be
unneeded/outdated.
I hope you all enjoy Lyon.
Cheers
Johnk
On 09/08/2011 01:44 PM, Jon Kerr Nilsen wrote:
Hi all,
OGF 33 is approaching and there will be a working session for UR-WG. As you might be aware of, EMI has created a description for a storage accounting record (StAR) to be proposed as an OGF standard (or as input to a new usage record). I would therefor like to ask for some last comments on the StAR document, to be found here:
http://cdsweb.cern.ch/record/1352472?ln=en
I'd need input to it within September 16 to be able to discuss it at OGF.
thanks,
Jon
UR-WG co-chair
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