2011-11-29    UR-WG Minutes

Present:  Mike Jones (minutes), Andrea C, Tanya L, Ralph M P, John G, John A K.

(NB unable to attribute most comments to an individual ?? used where I was 
unable to identify the speaker)

1, "Nomination of the new chairs is closed and the vote shall be casted"

  Two nominations were received via email to the list:
  Andrea Cristofori 
    Proposed: JAK
    Seconded: JG
  Jon Kerr Nilsen
    Proposed: JG
    Seconded: JAK

  No objections were received to the list.
  Both parties agreed to take up the position (JKN acknowledged via email).
  It was agreed unanimously at the telecon that both would chair the group.
  Action MJ: to inform Andre Merzky and Joel Replogle

2, "Comments on the info added on ValidDuration and TimeDuration"
  Publishing Allocated Space - also a previous action JG supplied email as gridforge site was down.

  Discussion started with Publishing Allocated Space

  MJ attempted to summarize the email discussion as a need to deal with 3 types of storage space usage:
   1 'used space' -- data size over a period of storage
   2 'blocked' space -- reserved space for available data storage
   3 'discretisation' space -- space used by storage system for stored data
  ?? - noted that StAR has the concept of:
    FILE SIZE
    LOGICAL SIZE
    PHYSICAL SIZE
  ?? - Analogies to CPU were drawn wall-clock versus CPU time. i.e. 
  When the use of a CPU renders it unavailable to other users the job consumes a whole CPU 
  over the wall clock time.
  MJ this ought to be similar to 'discretisation' versus 'used space'
  JG - highlighted the VO wants to know the VO's ̣agreed storage _Allocation_:
    It is an important use case for WLCG that the VO knows its allocation is there.
  MJ - concurred that there is a need to know this.

  ?? - Need to know the difference between an allocation and a usage

  There was a discussion about STORAGE CLASSes would appropriately differentiate between 
  URs for allocation and data storage but it was demonstrated that this was not the an
  appropriate field to use.

  ?? - analogies between VO based queues and CPU usage where drawn

  JG - we should try not to to base our usage requirements for storage upon CPU examples

  MJ - some level of coherence is helpful though.

  MJ - In an attempt to avoid allocation statements in each UR MJ Attempted to describe 
  a hierarchical view of usage records but was unable to get the point across.  
  Issues of having to search for allocation data which matched usage data were countered 
  by having to have data about allocation in each UR.

  Action MJ: to provide the hierarchical model and use cases for next meeting.

  Discussion continued onto TimeDuration and ValidDuration.
  Some were against recording any integral time information.
  MJ - vehemently against removing a duration element: we are not cutting status records.
  Following on was a discussion regarding how most storage systems can not at 
  this point in time deal with actual storage quantities based on IO level operations.

  Amazon model was brought up with an example: over 4 weeks if you use 1 GB for two weeks 
  then 3 GB for two weeks you are charged 8 GB weeks.

  General agreement that there should be some element of duration.

  ValidDuration was discusses and the concept of predictions as to the validity of usage data.
  MJ - Usage records are about past events and they shouldn't therefore contain assertions about
  future information.

3, "Comments on the document type to be presented before next OGF"
  It was decided that the next action will help the group decide how to proceed.
  

4, "Organization of the work on the document" 
  "(we will add a new wiki page were we will propose a list of fields with a short description. Everyone 
   is invited to give comments on fields name, description, etc. The final document will try to 
   armonize and consider...