4/20/02 APS April Meeting 1

Database Replication at Database Replication at Remote sites in PHENIXRemote sites in PHENIX

Indrani D. Ojha

Vanderbilt University

(for PHENIX Collaboration)

4/20/02 APS April Meeting 2

Index

PHENIX Computing Model Need for Database Replication Methods Summary

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PHENIX Computing Model

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Need for Database Replication

Simulation starts with event generation followed by detector simulation

Realistic event reconstruction processes need detector calibration data

This is stored into Objectivity/DB Local copy of DB improves the availability of these

critical data Enhances read performances when accessing these

data Less burden on central computing system (rcf) by

using outside computing power and storage

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Replication Methods

Homemade backup/restore– PHENIX rebuilds software each night– Makes a backup copy of database at Rhic

Computing Facility– Remote sites get backup copy of PHENIX

Federation– Restore and install locally– This is not automatic– http://phenix.phy.vanderbilt.edu/~ojha/objy/objy

_vmps.html

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Objectivity/DB: Data Replication Option

Create multiple copies of database on same machine or across LAN/WAN

Provide full read/write access to replicated databases

Update of one database image automatically updates others

Useful for PHENIX – High read performance– Low update frequency

Test version is working at Vanderbilt

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Data Grid: Grid Data Mirroring Package

Grid technology is popular in distributed and parallel computing

Data grid is ‘Data intensive Grid’ Provides access to terabytes of distributed and

replicated data Requires data consistency, security and high speed

transfer GDMP provides asynchronous replication

mechanism (CMS, CERN) GLOBUS toolkit is used for middle-ware

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Customize: Grid Data Mirroring Package

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Summary

For a few replication ‘Back-restore-install’ method is working

Objectivity/DB DRO is working, need more testing

Customize GDMP is a promising option