RegionalProductionV02 - US-Requested Additional Production: Summary of ATLAS Policy and US Practice (Version 2, 7/13/20100

RAC summary of ATLAS policy.

The first version of this document is still available.

The “ATLAS Policy leading to approval of Physics results” https://twiki.cern.ch/twiki/pub/AtlasProtected/AtlasPolicyDocuments/Physics_Policy.pdf lays out the conditions of validity for both ATLAS-wide and Private Monte-Carlo production. The flavor (read the policy for the details) of the policy is:

• Private productions that increase the size of existing samples:
  • the relevant analysis group must (be persuaded to) make sure that checks are made on a small subset of the data and validation plots are reproduced.
• Private production using new parameters and software:
  • after appropriate testing,
  • secure the approval of the relevant analysis group for the parameters/software,
  • secure the tagging of the parameters/software in the ATLAS software distribution,
  • perform full validation of a small sample made using the ATLAS production system,
  • Increase the sample size as above.
• All privately produced samples can only be considered valid if they are accessible to the entire Collaboration.

Current ATLAS approach:

The expression "Additional Production" is currently the favored way to describe production other that the centrally managed official production.

There is a strong preference for making the physics-group-approval and production process for additional production identical to those for centrally managed official ATLAS production. This strong preference is backed up by a demonstrated willingness of the central production team to handle additional production requests

The US ATLAS Operations team may use unpledged CPU resources, or unused pledged CPU resources, for US additional production. The initial priority for access to CPU resources will be (1=high):

Production Category	Pledged CPU	Unused Pledged CPU	Unpledged CPU
ATLAS-wide	1		2
US-requested Additional Production following ATLAS policy for validation		3	3
Any other US regional		4	4

The relative priorities of ATLAS-wide and US-regional access to unpledged CPU resources may be adjusted in consultation with the US ATLAS physics community and the resource owners. Priorities within a US-regional production category will be adjusted in consultation with the US ATLAS physics community.

Disk space may also limit US regional production, but since the introduction of PD2P (Panda Dynamic Data Placement) disk space issues have receded, at least temporarily.

What is the Difference between ATLAS-wide Production and a valid US-Requested Addtional Production?

Very little! The RAC encourages following the ATLAS validation requirements. This should, in principle, allow the production to run either as ATLAS-wide or as US-Regional with exactly the same validlity. Nevertheless, US ATLAS has a strong interest in seeing all of its facilities effectively used and demonstrating that, while fully meeting the spirit and the letter of pledges, the facilities are also helping to make the US ATLAS community competitive!

Making the created datasets valid for ATLAS results is very strongly encouraged. The approvals and validation steps are exactly the same for central ATLAS production and US Regional Production.