manchester computing supercomputing, visualization & escience celia russell, stephen pickles and...

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Celia Russell, Stephen Pickles and Mike Jones

Combining Data WorkshopESRC Research Methods ProgrammeManchester, December 18, 2002

SAMDSAMD

Seamless Access to Multiple Datasets

A ESRC/DTI e-Science demonstrator project

http://www.sve.man.ac.uk/Research/AtoZ/SAMD

Supercomputing, Visualization & eScience2

SAMD

Seamless Access to Multiple Datasets

A project to demonstrate the benefits of applying e-Science grid technologies to an ordinary social science query

We solve a genuine problem from the UK academic social science community - a multivariate analysis using a complex mathematical algorithm

Based on a major social science databank, the Office for National Statistics Time Series Data, hosted at MIMAS


The problem

Published as Sensier, M., Osborn D.R. and Öcal N. (2002) ‘Asymmetric Interest Rate Effects for the UK Real Economy’ , Oxford Bulletin of Economics and Statistics, Volume 64, September 2002, n°4

The research query looks at the effect interest rate changes had on Gross Domestic Product in the UK over the period 1960 – 2000


Interest Rates in the UK


UK GDP – quarterly changes


The Model

Where y is the quarterly change in GDP and z is the quarterly change in interest rates


Before SAMD


e-Science Grid


SAMD Methodology

We built a mini demonstrator grid for SAMD by: Grid-enabling the NS Time Series Databank Parallelising the code to represent the HPC facilities Using Grid protocols for data transfer Creating a graphical user interface that included a

single sign-on It all worked, and cut the data collection and analysis

time down to around 8 minutes.


Extending SAMD

The approach and methods of SAMD are applicable to more general social science applications involving data collection and analysis

More efficient handling of datasets – data is moved to where it's needed, not just to web browser

The single sign-on for all databanks means users can cross search datasets and perform cross analyses of multiple datasets from different providers

Grants access to high performance computing facilities on the grid without the user having to learn how to use them

Can automate routine enquiries Cuts the time taken to run computing intensive problems by a

factor of around 100


Scaling up with the Grid

E-Science Grids allow the social scientist to scale up their quantitative research by:

Including many more data points in their analysis Developing more complex models incorporating more

variables Dropping assumptions Visualising data Creating new communities and collaborations Exploring new types of analyses

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SAMD Architecture


Motivation

Web-based access to socio-economic datasets such as Office of National Statistics Time series data has lead to greatly increased use, but:-

No standard authentication or authorisation– too many usernames and passwords to remember

To automate search and retrieval, can only emulate navigation through "screen scraping"

– breaks whenever the interface is "improved"– discourages third party developments and periodic re-analysis

Data must be downloaded and saved to local disk– not necessarily the system on which subsequent analysis is to be

performed– inefficient, especially for large datasets


The SAMD solution

Use Grid Security Infrastructure for "single sign-on" authentication everywhere

– Modified standard Apache web server to accept proxy credentials• Permits re-use of existing CGI code

Use third party file transfers (grid-ftp) to move data directly to where it's needed

Use standard globus mechanisms to– Locate HPC facility for analysis– Stage analysis binary from local repository and run analysis job on

HPC facility– Retrieve results


Architecture


What's new?

Web interfaces to datasets?– We show that there are more flexible ways of delivering access to

data over the internet than through static web pages alone

Single sign-on?– We show that the domain of single sign-on can be much broader

than provided by Athens

Graphical User Interfaces?– We show that it's possible for a third party to develop new tools

independently of data providers– A short script can encapsulate all the essential functionality of the

SAMD GUI

Integration, Interoperability!


What's needed?

Culture of Standards

If key datasets are Grid-enabled in a commonly understood, well-documented way, we create an environment in which third parties can develop tools and services that add real value by bringing together independent datasets

SAMD shows that such an environment is technically possible, but does not by itself establish any standard.

– Look to Web services, Grid services, OGSA-DAI…

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SAMDUser Interfaces


GUI: Single Sign-on

Panel located at the top left Uses X509 proxy certificates grid-proxy-init

– Creates your proxy credential

grid-proxy-destroy– Removes your proxy credential


GUI: Data Acquisition

The Interface to the SAMD-ONS web server, steps 1 to 8


Data Search

Search by Keyword

1 Request and Mutual Authentication using a proxy credential

2,3 Authorisation

4 Query Data Store


Data Request

Data moved to GridFTP server 1: send references to data 1,2,3: authentication & authorisation 4: ask datastore to move data (5) 6,7: datastore returns XML ticket


Data Transfer

Data moved to HPC engine 8: third party file transfer

– from MIMAS to HPC engine, ready for analysis


Finding an HPC Resource

GIIS MDS Server e.g. ginfo.grid-support.ac.uk

Search for: OS type eg: IRIX64 Minimum No. Processors Jobmanager

or manually enter your favourite

Data Analysis panel


Select an executable on the local machine

Stage job using Globus Check status using Globus Retrieve results using Globus Clean-up using Globus Even delete job using Globus

Data Analysis panel

Using the HPC Resource


Command line automation

Not everyone has the expertise or time to write a special- purpose GUI.

Given a GSI-enabled web server and documented protocol to communicate with it, a few lines of shell script can do all the essential steps

Use grid-proxy-init to sign on Use curl to talk https to the web server Use GridFTP to move data to the HPC engine Use globus-commands to

– (stage and) run executable.– retrieve results– and clean-up


Acknowledgments

Funded by the and the

Keith Cole

Celia Russell

Marianne Sensier

Geoff Lane

Tim Hateley

Mark Riding

Kevin Roy

manchester computing supercomputing, visualization & escience celia russell, stephen pickles and...

Documents

data collection

data transfercreating

data points

analysis time

escience grid technologies

major social science

search datasets

social scientist