1. 4/20/02APS April Meeting1 Database Replication at Remote sites in PHENIX Indrani D. Ojha Vanderbilt University (for PHENIX Collaboration)

2. 4/20/02APS April Meeting2 Index  PHENIX Computing Model  Need for Database Replication  Methods  Summary

3. 4/20/02APS April Meeting3 PHENIX Computing Model

4. 4/20/02APS April Meeting4 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

5. 4/20/02APS April Meeting5 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 http://phenix.phy.vanderbilt.edu/~ojha/objy/objy _vmps.html

6. 4/20/02APS April Meeting6 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

7. 4/20/02APS April Meeting7 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

8. 4/20/02APS April Meeting8 Customize: Grid Data Mirroring Package

9. 4/20/02APS April Meeting9 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