STAR Analysis Operations and Issues

1. STAR Analysis Operations and Issues Torre Wenaus BNL STAR PWG Videoconference BNL August 13, 1999

2. Basis of planning • CAS processing with DST input based on managed production at the PWG level using the Grand Challenge Architecture • Later stage processing on uDSTs (standardized at the PWG level) and ‘nanoDSTs’ (defined by individuals or small groups) occurs under the control of individual physicists and small groups • Mix of LSF-based batch, and interactive • and later PROOF-like analysis? • on both Linux and Sun, but with far greater emphasis on Linux • For I/O intensive processing, local Linux disks (14GB usable) and Suns available • Usage of local disks and availability of data to be managed through the file catalog PWG meeting 8/99

3. Production Database • Components of the (for want of a better term) production database: • File catalogs • Simulation data catalog • populated with all simulation-derived data, from fzd to dst, in HPSS and on disk • Real data catalog • populated with all real raw data in HPSS; dst data and disk resident data not yet in DB (disk raw data shown in web interface) • Run log and online log • fully populated and interfaced to online run log entry • Event tag databases • database of DAQ-level event tags exists. Populated by offline scanner; needs to be interfaced to buffer box • Machine catalog (not yet existing) • Disk volume catalog (not yet existing) PWG meeting 8/99

4. Needed to implement GC in STAR • GC client gcaClient interfaced to StIOMaker in root4star • User provides query, or • User provides list of run/events, and components needed • StIOMaker ‘file open’ is submission of query/list to GC • StIOMaker ‘event read’ in event loop is • delivery of ‘this event is ready’ from GC event iterator; files containing needed components are available on disk in locations returned by GC • perform file open/data load for the needed components of the event • proceed to the loop over makers as usual • Will look to user like just another input type handled by StIOMaker • GC interface to STAR file catalog • Catalog itself is in place • Currently, event boundaries of files the same for all components • Need to answer ‘what file is each event component in for this event’ in general case • File catalog must include event ranges for files PWG meeting 8/99

5. Grand Challenge queries • Queries based on physics tag selections: • SELECT (component1, component2, …) • FROM dataset_name • WHERE (predicate_conditions_on_properties) • Example: • SELECT dst, hits • FROM Run00289005 • WHERE glb_trk_tot>0 & glb_trk_tot<10 • Event components: • fzd, raw, dst-xdf, dst-root, hits, StrangeTag, FlowTag, StrangeMuDst, … • Mapping from run/event/component to file via the database • GC index assembles tags + component file locations for each event • Tag based query match yields the files requiring retrieval to serve up that event • Event list based queries allow using the GCA for general-purpose coordinated HPSS retrieval • Event list based retrieval: • SELECT dst, hits • Run 00289005 Event 1 • Run 00293002 Event 24 • Run 00299001 Event 3 • ... PWG meeting 8/99

6. Physics tag generation • In doEvents.C based chain (or tacked onto end of bfc) • include StXxxTagMakers in chain • each tag maker provides a tag() method to return tag pointer • gather tags for output in a following maker StFlowTagMaker* flowMaker = (StFlowTagMaker *) GetMaker("FlowTag"); FlowTag_st* aTag = flowMaker->tag(); • Spit them out to a Tag.root or XxxTag.root file(s) • Catalog them along with other event components in DB • David Zimmerman is working on writing them out; then • Add them to catalog available to users and use them in GC index building • Add their generation/output to standard production • Multi-file, directory-scanning modes of doEvents.C can be used to process sets of tag files, or they can be catenated PWG meeting 8/99