1. High Energy Physics Data
Management using
CLOUD Computing
ANALYSIS OF THE FAMOUS BABAR EXPERIMENT DATA HANDLING
PAPER BY: ABHISHEK DEY, CSE 2nd Year | DIYA GHOSH, CSE 2nd year |
Mr. SOMENATH ROY CHOWDHURY
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2. Contents
 Motivation
 HEP Legacy Project
 CANFAR Astronomical Research Facility
 System Architecture
 Operational Experience
 Summary
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3. What exactly is BaBar?
 It’s design was motivated by the investigation
of CP violation.
 set up to understand the disparity between
the matter and antimatter content of the universe
by measuring CP violation.
 BaBar focuses on the study of CP violation in the B
meson system.
 nomenclature for the B meson (symbol B) and
its antiparticle (symbol B, pronounced B bar)
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4. BaBar : Data Point of View
 9.5 million lines of C++
and Fortran
 Compiled size is 30 GB
 Significant amount of
manpower is required to
maintain the software
 Each installation must be
validated before
generated results will be
accepted.
CANFAR is a partnership between :
– University of Victoria
– University of British Columbia
– National Research Council, Canadian Astronomy
Data Centre
– Herzberg Institute for Astrophysics
 Helps in providing Infrastructure for VMs.
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5. Need for Cloud Computing:
 Jobs are embarrassingly parallel, much
like HEP.
 Each of these surveys requires a different
processing environment, which require:
 A specific version of a Linux
distribution.
 A specific compiler version.
 Specific libraries
 Applications have little documentation.
 These environments are evolving rapidly
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6. DATA is precious,
too precious..
We need Infrastructure,
which comes easily as a
Service
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7. A word about Cloud Computing:
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8. IaaS: What next?
 With IaaS, we can easily create
many instances of a VM image
 How do we Manage the VMs
once booted?
 How do we get jobs to the
VMs?
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9. Our Solution: Cloud Scheduler + Condor
 Users create a VM with their
experiment software installed.
 A basic VM is created by one group,
and users add on their analysis or
processing software to create their
custom VM.
 Users then create batch jobs as they
would on a regular cluster, but they
specify which VM should run their
images.
CONDOR
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10. Steps for the successful architecture
setup:
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12. 5/25/2013
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13. 5/25/2013
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14. CANFAR : MAssive Compact Halo
Objects
 Detailed re-analysis of data from
the MACHO experiment Dark
Matter search.
 Jobs perform a wget to retrieve the
input data (40 M) and have a 4-6
hour run time. Low I/O great for
clouds.
 Astronomers happy with the
environment.
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15. Data Handling in BaBar:
Analysis Jobs
Event data
Real Data
Simulated
Data
Configuration
BaBar
Conditions
Database
 Data is approximately 2PB.
 The file system is hosted on a
cluster of six nodes, consisting of
a Management/Metadata
server (MGS/MDS).
 five Object Storage servers
(OSS).
 single gigabit interface/VLAN to
communicate both internally
and externally.
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16. Xrootd : Need for Distributed Data
 Xrootd is a file server
providing byte level access
and is used by many high
energy physics experiments.
 provides access to the
distributed data.
 a read-ahead value of 1 MB
 a read-ahead cache size of
10 MB was set on each
Xrootd client
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17. How a DFS works?
 Blocks replicated across several
datanodes(usually 3)
 Single namenode stores metadata (file names,
block locations, etc.)
 Optimized for large files, sequential reads
 Clients read from closest replica available.(note:
locality of reference.)
 If the replication for a block drops below target, it
is automatically re-replicated.
Datanodes
1
2
3
4
1
2
4
2
1
3
1
4
3
3
2
4
Namenode
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18. Results and Analysis:
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19. Fault tolerant model:
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20. Acknowledgements
 A special word of appreciation and
thanks to Mr. Somenath Roy Chowdhury.
 My heartiest thanks to the entire team
who worked hard to build the cloud.
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21. Questions Please?
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