50 likes | 162 Views
Conditions DB brainstorming PhC, April 27th 2005. Requirements Operational issues. Requirements. Stored data From ECS, single version (ambient conditions, configurations…) From trigger: trigger conditions (1 or 2 thresholds)
E N D
Conditions DB brainstormingPhC, April 27th 2005 Requirements Operational issues
Requirements • Stored data • From ECS, single version (ambient conditions, configurations…) • From trigger: trigger conditions (1 or 2 thresholds) • From quasi-online: VeLo alignment (2 numbers at each start of fill) • From offline: longer latency alignment / calibration • Usage • Reconstruction software (L1, HLT, offline) • Physics analysis (e.g. dead channels…) • Trigger reproduction (buffer tampering) • Request to co-exist with latest version for reconstruction Philippe Charpentier
Implementation questions • Offline usage: • IoV database backend (COOL) • Definition of the payload (currently XML supported) • In memory: loaded from DetectorElements • Online usage • No database backend (?) • Blob downloading to farm nodes, from “snapshot”? Needs to define a format (XML?) • Special CondDB service (no validity date, single instance of each item) Philippe Charpentier
Operational issues • Where is the master DB? • Who runs the service at the pit? • Synchronisation with offline? • Offline updates • Asynchronous updates. Update format? • Online updates • Synchronous update of the DB (no buffering) • DCS conditions: how do we connect ECS to update process? • Online monitoring conditions (e.g. VELO alignment) • Gaudi process collecting info from farm nodes (Gaucho?) • Trigger settings (keep rate when lumi changes) Philippe Charpentier
Online operational issues • Start of run • Create snapshot, load farm (Gaucho? Delegate to SFCs?…) • During run • What conditions need updates to the farm? • Only if sensitive for trigger decision • Atmospheric pressure (RICH)? • Trigger thresholds • Is it possible to load a new snapshot on the fly? • Is it needed? If few conditions, include in data? • How to ensure trigger reproducibility offline with same conditions? • Proposal: use different conditions for trigger and reconstruction • I.e. different DetectorElements? Philippe Charpentier