User Documentation

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This page contains useful information regarding the accounting within the LinkSCEEM project. Users are advised to read the content of the page, to be aware of our accounting policies.
Basic Structure

The accounting within LinkSCEEM is project-based. Calls for Proposals are released and submissions are scientifically and technically evaluated. Successful proposals are given an allocation on an HPC machine that they are required to use within a defined period of time. This model lends itself well to a project focused organizational structure:

  • A Unix Group ID is created for the successful project
  • A new account is created for each member of the project with the gid set to the project group. Therefore each uid is unique to a project (and users may have multiple accounts)
  • The home directories of users are contained within a project directory, e.g., user 'li001' within project 'linkSCEEM' would have a $HOME directory defined as /home/linkSCEEM/li001
  • The work directories of users would follow a similar structure, with e.g. $WORK defined as /lustre/linkSCEEM/li001
  • While users having multiple accounts might be seen as a disadvantage, this approach has a number of significant advantages from a system administration level. In particular, project-level quota and HPC accounting methods can be implemented based on the gid information and this directory structure.
Uniform Usage Policy

The uniform usage of system resources is considered essential and projects will be incentivised to spread their usage across the entire allocation period using the following system:

  • For accounting purposes, the fixed quota of the project is divided into equal monthly portions over the duration of the project.
  • Each monthly portion can be carried forward for a maximum of two months, after which unused quota will be forfeited
  • The following formula will be evaluated for each project at the end of each month

    Total Used Quota - ( (Fixed Quota Allocated by RAC) / (Number of months of project) )* (Number of active months-1)

  • If the above formula returns a negative number then the project leader is sent an email notifying them that their usage is below expectations and that they may forfeit quota the following month unless usage is increased. By construction this email can only be sent from the second month of the project.
  • The following additional formula is used to evaluate the amount of forfeited quota (and is only valid from end of the 3rd month by construction)

    Total Used Quota -( (Fixed Quota Allocated by RAC) / (Number of months of project) ) * (Number of active months-2)

  • When the above formula returns a negative number the project leader is sent a mail saying the project has forfeited this amount of quota due to low utilization. This forfeited quota is subtracted from the fixed quota available to the project on the system.
  • The Total Used Quota in the formulas above is the total quota usage of the project from start date (as reported by the system) PLUS the total forfeited quota of the project to date
  • At the end of the second-to-last month of the project the formula for the warning email is changed to

    Total Used Quota - ( (Fixed Quota Allocated by RAC) / (Number of months of project) ) * (Number of active months)

Furthermore, if a project is awarded a computational allocation and after the first six months achieves less than 10% of its expected usage (without just cause), the project may be penalized 80% of their whole allocation which can either be released back into the allocation pool of the next production call or be reassigned to other high utilization projects.

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