STARCOMPUTING

STAR Analysis Operations and Issues

Torre WenausBNL

STAR PWG VideoconferenceBNL

August 13, 1999

Torre Wenaus, BNL

PWG meeting 8/99STARCOMPUTING

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

Torre Wenaus, BNL

PWG meeting 8/99STARCOMPUTING

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)

Torre Wenaus, BNL

PWG meeting 8/99STARCOMPUTING

Needed to implement GC in STARGC 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

Torre Wenaus, BNL

PWG meeting 8/99STARCOMPUTING

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

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

...

Event list based retrieval:

SELECT dst, hits

Run 00289005 Event 1

Run 00293002 Event 24

Run 00299001 Event 3

...

Torre Wenaus, BNL

PWG meeting 8/99STARCOMPUTING

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

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

StFlowTagMaker* flowMaker = (StFlowTagMaker *) GetMaker("FlowTag");FlowTag_st* aTag = flowMaker->tag();