1. 1 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Distributed Storage management using SRB on UK National Grid Service Manandhar A, Haines K, Brown G.D, Kleese K, Berrisford P. CCLRC

2. 2 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Overview SDSC SRB overview SRB Features of interest Issues focussed for this deployment Deployment Structure Expected usage scenario Future development Questions

3. 3 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham National Grid Service The National Grid Service is a new initiative to provide computing resources to the e-Science community Services Computational service File management service Database service For providing file management services on the National Grid Service, Storage Resource Broker is being used.

4. 4 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham SRB for Data Grid The SDSC Storage Resource Broker is a middleware that virtualises storage space by providing a unified view to multiple heterogeneous storage Resources over the network. It is a software that sits in between users and resources and provides a storage service by managing users, file locations, storage resources and metadata information and enables collaboration in an Grid environment Data Grid Disk space @ loc y Disk space @ loc x MSS Space @ loc z

5. 5 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham SRB Logical Structure DB SRB View User/Process Disk Farm Tape Farm RDBMS The logical directory structure and the physical file locations are maintained in a Database. Also other persistent information such as User accounts, Participating resources and file meta data are stored in it.

6. 6 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Features of interest Logical abstraction to multiple heterogeneous storage resources. Ability to inter-operate with Grid applications with GSI authentication mechanisms Fine grained access control mechanism for file access Device driver interface to disk arrays, and to mass storage systems such as Atlas and HPSS. Bulk file and parallel transfers for performance enhancements while transferring multiple small files Lightweight clients for access to data from Unix, Windows, Macintosh and browser based interface. C, Java, Python and Webservices API for closer interaction with programs

7. 7 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Issues focussed for this deployment Reliability As data is a very important part of a project, reliability of the system has been given a very high priority. The system is made reliable by having online replication at many different layers. Inter-operability Easy inter-operability with the computational service and other Grid applications by the use of common authentication mechanism and enabling easy data sharing between projects. Multi project hosting Hosting of multiple domains and enabling access control of certain resources to only specific projects in the SRB network for supporting multi project hosting. Future Scalability Enabling SRB federation for data interaction with other SRB installations and for scaling future deployment

8. 8 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Deployment Structure Online Replication SRB Server SRB server @ RAL Resource Driver MCAT SRB server @ Oxford Resource Driver Database Servers @ RAL User Disk Farm Disk Farm MCAT Server @ RAL DB1 DB n Database Servers @ Manchester DB1 DB n SRB Server MCAT MCAT Server @ Manchester Failover link Disk Farm SRB server @ HPCX Resource Driver Disk Farm SRB server @ Leeds Resource Driver Disk Farm

9. 9 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham MCAT Enabled Server RAL Oracle Replication Replication Structure Oracle Client ….. Oracle 9i RAC (Nodes 1.. 8) MCAT Enabled Server Manchester RAL Oracle Client ….. Oracle 9i RAC (Nodes 1.. 8) Storage Server User Fail over link

10. 10 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Projected use of NGS SRB (1) In an SRB network, the MCAT is the most time consuming and expensive to maintain. Projects may utilize the MCAT service provided by NGS in maintaining their distributed file service and add their existing storage resources to the NGS SRB. In doing so they can also collaborate with other participating projects easily. SRB server @ Project Resource Driver Disk Farm SRB server @ Project Resource Driver Disk Farm NGS SRB Disk space MCAT Computational Farm (project) NGS Computational Farm

11. 11 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Projected use of NGS SRB (2) SRB Space (Used as a Project file system) Use of SRB as a project file system and with Condor/Globus – e-Minerals project Condor Client Tools/ DAG Clients Globus 2.4 Compute Cluster @ Oxford User @ Cambridge User @ UCL Condor G interface Condor Pool @ Cambridge Code Repository Linux Solaris Data Repository

12. 12 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Projected use of NGS SRB (3) Some projects such as the Integrative Biology project have the requirement to with other SRB networks. It is expected these projects would use the federation feature of SRB for inter-organizational collaboration. Also as projects progress they may want to maintain their own MCAT and create federation links with the NGS SRB for collaborating with other projects in there or use other services provided by NGS. DB SRB DB SRB DB SRB Trust Relation NGS Zone Zone BZone A Trust Relation

13. 13 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Future additions More use of Federation concepts for Scaling SRB installation (with other NGS sites or new projects) Performance improvements Look into different replication usage for performance and reliability improvements Improve SRB administration by possibly moving to a decentralized management from currently centralized SRB management.

14. 14 e-Science AHM 2004 31 st Aug – 3 rd Sept 2004 Nottingham Questions..