Organization, responsibilities, authorities and policies related to Embedding

Due to the increasing demand of the STAR collaboration, associated to the need for redundancy and more cohesion in the embedding activity, the embedding structure will move toward a distributed (computing) model paradigm with a structured set of responsibilities.

Organization

The embedding activity is a cross between the Simulation and Reconstruction activities and an important part of our data mining and data analysis process. Hence, the Embedding structure described below is an activity part of the Software & Computing (S&C) project structure.
The embedding activity will be led by the Embedding coordinator (EC) helped by embedding deputies (ED) whose responsibilities and authorities are described below. It is understood that each Physics Working Group (PWG) may assign a contact person to help running an embedding series, or an embedding helper (EH). EC, ED and EH constitute the embedding team and core structure.
Embedding tasks will be created consistent with Appendix A “Initiating Embedding requests”.

The EC

The primary mission of the EC is to organize the work and the set of QA results related to each of the embedding series and communicate to the collaboration the progress and difficulties encountered in the data production process. The EC is the interface to many areas in STAR and to efficiently achieve the goals prescribed by the function, his/her responsibilities and authorities are described below:

The EC responsibilities are:

• The EC will work in close relation to the S&C Leader, Physics Analysis Coordinator (PAC) and the PWG Convener (PWGC) to define and facilitate the processing of the embedding requests needed by the collaboration to carry its scientific goals
• The EC will work with the PWG and gather keep up-to-date a set of macros and code aimed to provide appropriate QA for the PWG of interest
• The EC is responsible for the communication with the PWGC whenever embedding requests clarifications are needed
• The EC will communicate and feedback to the S&C leader any issues related to resources needed to accomplish the mission.
  • This may include discussions involving tasks lists and priorities, assignment of additional manpower, addition of computational resources allocations or difficulties encountered during the embedding process.
  • The discussions may be substantiated by resource need document provided by the EC as requested.
• The EC is responsible for regularly bringing to the collaboration, via weekly S&C meeting venue, summaries of the tasks at hand and presenting the priorities or priority reshape as applies. All modified embedding requests are expected be announced at “a” S&C meeting as a summary and in addition of the communication with the PWGC. The frequency of such intervention is at the discretion of the EC and should not be below once a month
• The EC will be responsible for communicating with the ED and organize the work and tasks with the ED forming the core force of the embedding
• The EC is expected to handle and resolve with the ED issues which may be raised by the EH

The EC authorities are

• Assign tasks as applies to the ED

• Request highly prioritized resource allocation to perform tasks
• Contact and discuss directly issues related to embedding requests with PWGC, PAC or S&C leader as applies
• Authoritative decisions are granted to the EC on the following area:
  • Declare an embedding request as improper and re-direct to the simulation leader
  • Re-prioritize or close embedding tasks and requests upon PWGC feedback or lack thereof.
  • Similarly, close an incomplete request upon PWGC lack of feedback
  • Re-assign priorities to a low priority shall precisions on an embedding request not be provided
  • Has authoritative leverage to declare an embedding series as 'good or not', based upon quantitative arguments and backed by proper embedding related QA.
• May request discussions and/or arbitration ruling to the PAC and S&C leader shall a contention arise with PWG(C) of interest

• In the event an embedding request is re-directed, re-prioritized, closed, declared 'bad' and shall the decision be contested by the PWG or PWGC, the following applies:
  • The responsibility to present a case and burden of proof is on the PWGC
  • Explicit discussion and approval of both S&C leader and Physics Analysis Coordinator (PAC) is necessary for re-considering the EC decision

The ED

The Embedding deputies' role and responsibilities are the one previously expected of the PDSF Tier1 center in 2005.

Those responsibilities include

• Respond to the EC requests for assigned tasks and work unit and provide estimate on time and feasibility of a task
• Keep the EC informed of progress, issues and difficulties encountered during the setup of the embedding process including resource allocation difficulties if any
• Maintain the embedding framework consistent with a distributed model and provide feedback on improvements / fixes suitable for all sites

• Keep documentation up-to-date

• Work closely with the EH as applies to accomplish task at hand

• Directly communicate with the PWG Point of contacts issues related to geometry tag, magnetic fields and other parameters wherever applies (see appendix B)

The authorities of the ED include

• Manage global assigned local resources as necessary to perform tasks
• Reshuffle and assign portion of resources to EH as see fit to perform task
• Request EC intervention whenever necessary

The EH

The Embedding helpers are STAR collaborators helping with the running of the embedding and carry some of its burden. The EH is part of a workforce supplement provided by the PWG. EH may or may not be the PWG Point of Contact for a particular set of requests. PWG may or may not provide EH, understanding however that the lack of EH may result in delays in delivery of results.
The EH are expected to work closely with the ED and EC to perform their embedding task and consistent with the principles stated above. Especially, the EH have no particular responsibilities as per informing and explaining the PWGC or the PWG Point of contacts of inadequacy of the requests – this being described as the responsibilities of respectively the EC and ED.
Whenever an embedding request is determine valid by the EC and assigned to an ED, the EH will work within guidance and supervision of the assigned ED.

Appendix

Appendix A – Initiating Embedding requests

Embedding requests and need will be initiated and discussed within either PWG or R&D working group with respectively the supervision of the PWGC of interest or R&D simulation coordinator. The following caveats apply.

Pure embedding will be asked by PA of a pending publication / paper or whenever the accuracy needs to be as-close as possible to the real data. All other cases will be reviewed by the EC and may be transformed into a enriched sample simulation (“injection” simulation) wherever it applies and re-directed to the simulation leader consistent with the EC authorities.

After discussions within the PWG, embedding requests will be recorded by one of the PWGC via a provided interface which purpose will be to keep track of all requests and allow for priorities and overview of status and progress. The PWGC may designate an embedding point of contact as PWGC representative for embedding. In such case, the communication will be carried through the Embedding Point of contact.

No embedding requests outside of the provided framework and interface shall be satisfied and no “pending discussions” without an actual requests will be considered. It is also understood that a ill-defined requests may be closed by the EC consistent with the feedback gathering policy described in the EC responsibilities and authorities section. In such event, the request slot is not re-usable by the PWG.

Unless specified otherwise and priorities assigned explicitly by the PAC, EC or S&C leader, the requests will be considered as per a first in first done basis and upon availability of resources.

Appendix B – ED responsibilities and authorities regarding geometry tag and field settings

Upon request from the PWGC, the embedding team will ensure that the proper information is obtained as per the production series the embedding requests relate to. For a given production, the field setting and geometry tag used will be checked for consistency. Consistency must arise between simulation, real data and intended study. The geometry tag will be acquired from the production options page maintained by the production coordinator [currently Real Data production option].
The ED will be responsible for carrying those checks and will pass on functional macros to the EH assigned to assist them. If a setting is inaccurate (field or geometry tag), the EH shall immediately inform the PWG Point of Contact and the EC and request explicit confirmation. An embedding series shall not be started nor be run without the acknowledgment of the related field or geometry tag adequacy as chosen by the PWGC or PWG Point of Contact.