LIGO-G9900XX-00-M LIGO R&D1 TCS Chiller Performance Review Phil Willems Nov. 17, 2004.
LIGO-G9900XX-00-M LIGO and GriPhyN Carl Kesselman Ewa Deelman Sachin Chouksey Roy Williams Peter...
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Transcript of LIGO-G9900XX-00-M LIGO and GriPhyN Carl Kesselman Ewa Deelman Sachin Chouksey Roy Williams Peter...
LIGO-G9900XX-00-M
LIGO and GriPhyN
Carl Kesselman
Ewa Deelman
Sachin Chouksey
Roy Williams
Peter Shawhan
Albert Lazzarini
Kent Blackburn
Caltech USC/ISI
LIGO Scientific Collaboration 2LIGO-G9900XX-00-M
LIGO Virtual Data Grid
Caltech
MIT
LIGO Livingston
LIGO Hanford
LIGO Scientific Collaboration 4LIGO-G9900XX-00-M
LIGO Overview
To detect gravitational waves predicted by Einstein’s theory of relativity.
Waves created from» Rapidly spinning asymmetric compact objects eg. pulsars» Mergers of black holes, neutron stars -- gamma bursts?» Supernova collapse (and post-collapse R-modes)» Starquakes in neutron stars» Primæval GW from early universe
Installation in Louisiana and Washington State» Other projects: Virgo (Italy), GEO (Germany), Tama (Japan)
LIGO Scientific Collaboration 5LIGO-G9900XX-00-M
Physics and Virtual Data
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Su
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a Primeval GW Background
Mergers BH/NS
CW (eg pulsar)
MergerRingdowns
time
Each source type has different freq/time charactaristics
different virtual data requirements
LIGO Scientific Collaboration 6LIGO-G9900XX-00-M
LIGO Data
Time series, 16 kHz down to 1 Hz
~1000 channels:» Gravity wave
» seismic, magnetometer, microphone, engineering, … Power spectra, cross spectra, sonogram, … Events
» Each has time and SNR (signal to noise ratio)
» Candidate inspiral events from matched filter
» Other pattern matching
» “Examine the big ones, histogram the small ones”
LIGO Scientific Collaboration 7LIGO-G9900XX-00-M
Processing
Network» NVO is federation, LIGO is coincidence
» In both cases registration is important
LIGO vs NVO vs HEP
detector events
patternmatching
filterreduce
HEP
objects
detector
datacube
events
patternmatching
filterreduce
LIGO, NVO
RDBMS
1D,2D
LIGO Scientific Collaboration 8LIGO-G9900XX-00-M
Data Access
LDAS (Ligo Data Analysis System)» Script (Tcl) based
» Primarily for onsite analysis and archiving
» Talks to local files, Hanford/Livingston
» Has a filtering language– stack-based, like Matlab– functions eg power spectrum, fft, resample
LARS» Can talk to local, HPSS files
» Can do subsetting
» Simple program, simple protocol
LIGO Scientific Collaboration 9LIGO-G9900XX-00-M
Activities
1. Virtual Data» A: Language & Architecture
– Naming is Time/Channel/Transformation
– Smart subsetting
» B: LigoVista web display
– Archive at-a-glance + drill-down
2. Replication» A: Realtime mirror
– Hanford/Livingston/Virgo nternational coincidence study
» B: Fault-tolerant mirror
– from Caltech to UW/Milwaukee
3. Pulsar search» backfill on Condor farms
LIGO Scientific Collaboration 10LIGO-G9900XX-00-M
1A: Virtual Data: Language
Virtual Data:» Times + Channels,
– eg 668371475-668372499 (GPS time, seconds since 1981)– L0: PEM-LVEA_SEIS*, L1:LSC-AS_Q
» Transformations to Virtual Channels– eg. L0:PEM-EX-SEISX- L0:PEM-LVEA-SEISX / resample(L1:LSC-AS_Q, 1, 64)
Use LARS and Globus Replica Catalog For each requested data value, need to
» Determine if it is instantiated; if so, where; if not, how to compute it» Plan data movements and computations required to obtain all results » Execute this plan
LIGO Scientific Collaboration 11LIGO-G9900XX-00-M
1A: Virtual Data: Architecture
existing
in developmentplanned
ConnectivityConnectivity
Request Manager
“local”storage
HPSSat Caltech
OtherRemoteStorage
Replica Catalog
Replica ManagementReplica Selection
LDAP FTPGridFTP
DerivedData
Catalog
Transfor-mationCatalog
LARS Prot.
LIGO Application
Channel, start time, stop time Virtual Data URL
Power spectrum of seismic channels
P. C
harl
ton
LIGO Scientific Collaboration 12LIGO-G9900XX-00-M
1B: Virtual Data: LigoVista
Overview of archive in a web browser» Time based
– month, week, day, hour, ....
» Machine state– lock status, science run, event density, ....
» Drill down to raw data– Transformed data
» Uses Virtual Data framework– compute on the fly and cache
LIGO Scientific Collaboration 13LIGO-G9900XX-00-M
2A: Replication:Realtime
Look for coincidence in Ligo-Virgo data
LIGO Virgo
Interferometer,seismic. etc
Interferometer,seismic. etc
LDASanalysis
eventstream
streamingbidirectionaltransatlanticreplication
LIGO Scientific Collaboration 15LIGO-G9900XX-00-M
2B: Replication: Fault-tolerance
HPSS@Caltech Beowulf@UWiscMilwaukee
Replica Catalog
Replication API
Penn StateUT Brownsville
GridFTP
Master archive replicated at LSC sites• Fault tolerant
LIGO Scientific Collaboration 16LIGO-G9900XX-00-M
3. Pulsar Search
Infinite computation on finite data!» Tiny, precise signals in deep noise» Search on 4D space: sky position, pulsar frequency, spindown,
6 months data
Time (months)
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Hz)
Frequency modulation by Earth movement
UT BrownsvilleUW MilwaukeeCaltech CACRUW Madison
Condor farms0.5 TByte “image”
frequency bins
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timetime
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