Transcript belfast
GEDDM: Comparisons of OGSA-DAI and GridFTP for
access to and conversion of remote unstructured data in
legal data mining
Karen Loughran
The Queen’s University of Belfast
The Queen’s University of Belfast
Introduction
Grid Enabled Distributed Data Mining
Industrial partner
Overview of GEDDM
GEDDM Common Semantic Model (CSM)
objectives
Grid enabled solution
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Industrial Partner - Datactics
Northern Ireland based (formed 1999)
Specialising in grid enabled “data-centric”
matching across multiple sectors
Datactics technology is fully parallelised
Computationally intensive - need to compare
every record with every other record
Improve data quality by applying fuzzy matching
techniques
Data mining software being used in the real world
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GEDDM Business Driver
Data sources
numerous structures, formats, locations, administrative
domains…
Client
US County Court: insider trading litigation case
45Tb
Variety of formats
Email, pdf, weblogs, DBMS, report text dumps …
How to interface to large volumes of data in
common structured parallel approach
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Common Semantic Model (CSM)
Objectives
Representation of unstructured data such as
email, weblog, report dumps.
Conversion to structured format.
Evaluation of Grid technologies for access
and conversion.
Secure, reliable and scaleable.
Exploit high bandwidth.
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CSM Grid Enabled Solution
Two Stages:
Represent and convert unstructured Flat File
Formats (FFF) to structured Common Output
Format File (COFF).
Investigate Grid technologies for the remote
access and conversion of unstructured data.
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CSM Representation & Conversion
Data Description Language DDL - XSD
Data Description File DDF
Parser
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Sample FFF data source & DDF
App
IMP
Account
343818
IMP
565777
Address
Balance
Dede H Smith
8600.76
181 Glen Rd
Earls Court, London
Annie Saunders
9905.50
60 Newhaven St
Edinburgh, Scotland
___________________________________________________________________
<datasource>
<database>
<header><headertext>App Account Address Balance
</headertext></header>
<rectype eorecord=’\n’>
<pfield name=”App” pos=1 length=3/>
<pfield name=”Account” pos=10 length=6/>
<pfield name=”Address” pos=24 length=23
multiline=”yes”/>
<pfield name=”Balance” pos=49 length=8/>
</rectype>
</database>
</datasource>
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Parser Design
Object oriented component hierarchy
Each object represents an XML element
Encapsulates data relating to the flat file
component it describes
Encapsulates all import “parse”
SAX parse performed on DDF to build up
internal OO representation of FFF
Parse called on top level object.
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CSM Grid technologies
Transfer & conversion tools
OGSA-DAI (Version 4)
GridFTP (GT4.0.0)
GUI interfacing to both of these
technologies.
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GUI interface – access & conversion
GUI Interface to sample remote FFF, DDF creation and conversion.
View Sample
Describe (DDF)
Convert
Unstructured
FFF Data
Data Conversion
Services
View Results
(COFF)
Structured Data
(COFF)
No
OK ?
Conversion Module
Yes
Complete
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Implementation under OGSA-DAI
OGSA-DAI 4.0.0
Globus Toolkit 3.2.1
New conversion activity designed &
implemented
Calls out to python scripts to perform
conversion
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Implementation under GridFTP
Globus Toolkit 4.0.0
Data Storage Interface (DSI) creation to
perform conversion processing at server
Instead of original unstructured FFF, send
the COFF file back to client
Setup striped server architecture – multiple
nodes working together in parallel.
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GridFTP Striped Architecture
Belfast
London
Host A
Host X
Host B
Host Y
Host C
Host Z
Raid
Raid
Raid
Raid
Raid
Raid
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GridFTP Machine Specifications
BELFAST
AMD4400 Dual Processor
4Gig RAM
1 Terabyte hard disk, serial ATA2
1 Gigabit ethernet
LONDON
Dual Optron Processor
4Gig RAM
1 Terabyte hard disk
1 Gigabit ethernet
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GridFTP Evaluation Tests
Attempted conversion and access to large
files across the network.
File sizes:
13Mb, 26Mb, 52Mb, 103Mb, 205Mb, 409Mb,
817Mb, 1634Mb
Buffer sizes:
Default, 4915, 409150, 785408
MTU 1400 - 8000
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OGSA-DAI Benchmark Results
Currently no results available:
Socket Timeout Error and Engine receives a
terminate signal when Activity takes longer
than approximately 10 minutes to run.
DeliverToGridFTP activity would not work in
version 4. Patches required. So far, unable to
get working with these patches.
Security setup issues.
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GridFTP Network Topology
BBC NI
Queens
BBC London
100MBit
1GBit
1GBit
Janet Bar
Queens BESC Router
1GBit
1GBit
BBC
ROUTER
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Results – GridFTP transfer
Throughput hindered by:
Physical Infrastructure/Service Provider-80Mbs
Router/switches/NIC
808 Mbs CPU to CPU (London to Belfast)
688 Mbs Disk to Disk (BBC NI)
Striping with 2 BE servers - 60% improvement
Local 100Mbs switch:
Disc to disc – 82 Mbs
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OGSA-DAI Evaluation ….
DeliverToGridFTP not working in 4.0.0
Configuring GridFTP not possible (buffer sizes,
no. of streams, striped transfer etc.)
Some way to go in efficient transfer of large files.
Installation/runtime overheads
Design/code conversion activity & design perform
documents for access/conversion
Timeouts converting large files. Threads may be
solution.
Clear documentation
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GridFTP Evaluation
Secure, reliable, fast and scaleable
Lightweight installation
Optimum use of high bandwidth networks
Extra ERET/ESTO processing allows
tighter integration of conversions operation
through the definition of a DSI
Striping for much improved efficiency
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GridFTP Evaluation
Extensive tuning required
No clear documentation for writing a DSI.
[email protected] useful source of info
Poor performance on NFS.
PVFS like filesystem recommended for striping.
1Gbit bandwidth in practice difficult to achieve
due to problems with:
Router
NIC
Physical Infrastructure
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Conclusions
Investigated grid technologies for remote
access & conversion
OGSA-DAI disappointing due to lack of
support for large file transfer
GridFTP involved extensive configuration
and due to network infrastructure problems
difficult to get optimum performance in
remote transfer
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Future work
Tighter integration of conversion services
within GridFTP DSI server module.
Extend the services under GridFTP to cope
with Distributed Query Processing.
COFF produced as XML, ready for XPATH
queries.
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Questions ?
The Queen’s University of Belfast