Using Databases to Manage State Information for. Globally Distributed Data

Transcription

1 Storage Resource Broker Using Databases to Manage State Information for Globally Distributed Data Reagan W. Moore San Diego Supercomputer Center sdsc.edu/srb

2 Abstract The management of globally distributed data is simplified through the use of data grids which enable data sharing environments. Data grids provide: Interoperability mechanisms needed to interact with legacy storage systems and legacy applications Logical name spaces needed to identify files, resources, and users. Consistent management of state information about each file within the distributed environment. Access controls, descriptive metadata, and administration metadata. These capabilities enable data virtualization, the ability to manage data independently of the chosen storage repositories. Examples of management of globally distributed data include data grid federation, distributed digital libraries, and distributed persistent archives.

3 Research Questions How do we build global data management systems that rely on database technology to support state information? Is the current state of the art sufficient, or do we need extensions to current database technology?

4 lobal Data Management Precursor Alternative Architecture Study for NASA Earth Observing Satellite EOSDIS Mike Stonebraker, Jim Grey, Jeff Dozier, William Farrell, Reagan Moore Proposed aggressive use of database technology to manage 3 TBs data ingestion per day from multiple sites Replication of data 15 PB archive Discovery and manipulation of the collection Just in time acquisition of technology

5 Data Grid Evolution DARPA Massive Data Analysis Systems DARPA/USPTO Distributed Object Computation Testbed NSF National Partnership for Advanced Computational Infrastructure DOE Accelerated Strategic Computing Initiative data grid NARA persistent archive NASA Information Power Grid NLM Digital Embryo digital library DOE Particle Physics data grid NSF Grid Physics Network data grid NSF National Virtual Observatory data grid NSF National Science Digital Library persistent archive NSF Southern California Earthquake Center digital library NIH Biomedical Informatics Research Network data grid NSF Real-time Observatories, Applications, and Data management Network NSF ITR, Constraint based data systems LC Digital Preservation Lifecycle Management LC National Digital Information Infrastructure and Preservation Program

6 Terminology 1998 Data Grid, a data management system that organizes distributed data into collections Data Grid - data virtualization 2000 Persistent Archive, a data management system that handles technology evolution Persistent Archive - infrastructure independence

7 Data Grids: First Viewpoint Create a shared collection which manages state information independently from the storage systems Build a metadata catalog to store state information Separate data access mechanisms from storage access mechanisms Data Virtualization

8 Trust Virtualization Shared collection owns the data At each remote storage system, an account ID is created under which the data grid stores files User authenticates to the data grid Data grid checks access controls Data grid server authenticates to a remote data grid server Remote data grid server authenticates to the remote storage repository

9 Data Grids Largest single data grids ROADnet real-time sensor network, links 90 object ring buffers supporting 24,000 sensors BaBar high energy physics, distributes SLAC collections to Lyon,France and Rome, Italy Biomedical Informatics Research Network, links data resources across 25 institutions within the US Largest data grid federations KEK high-energy physics federation of 7 data grids between Japan, South Korea, China, Taiwan, Australia, Poland, US WUN federation of 5 academic institutions (SDSC, NCSA, U Bergen, U Southampton, U Manchester) NARA Research Prototype Persistent Archive (SDSC, U Maryland, NARA, GA Tech)

10 ata Grids: Second Viewpoint Support data management applications Automate all aspects of data discovery, access, management, analysis, preservation Security paramount Distributed data Provide distributed data support for Data sharing - data grids Data publication - digital libraries Data preservation - persistent archives Data collections - Real time sensor data

11 Generic Data Management Data grids provide capabilities needed by digital libraries and persistent archives Infrastructure independence to manage a collection distributed across multiple storage systems Descriptive metadata to describe authenticity context of each file Administrative metadata to maintain integrity Location, replicas, checksums, audit trails, ownership, access controls, versions, locks, pinning, aggregation Data grids are implemented as middleware Runs as application under an account ID

12 ederated Server Architecture Logical Name Or Attribute Condition Read Application Peer-to-peer Brokering Parallel Data Access SRB server /6 4 SRB server SRB agent 2 5 SRB agent 1.Logical-to-Physical mapping 2.Identification of Replicas 3.Access & Audit Control R1 MCAT Data Access R2 Server(s) Spawning

13 Storage Resource Broker Application C Library, Java Unix Shell Linux I/O C++ NT Browser, Kepler Actors DLL / Python, Perl, Windows HTTP, DSpace, Fedora, OpenDAP OAI, WSDL, (WSRF), GridFTP Federation Management Consistency & Metadata Management / Authorization, Authentication, Audit Logical Name Space Latency Management Data Transport Metadata Transport Database Abstraction Storage Repository Abstraction Databases - DB2, Oracle, Sybase, Postgres, mysql, Informix Archives - Tape, Sam-QFS, DMF, ORB HPSS, ADSM, UniTree, ADS File Systems Unix, NT, Mac OSX Databases - DB2, Oracle, Sybase, Postgres, mysql, Informix

14 orage Resource Broker Collections at SDSC (8/2/2005) GBs of data stored Number of files Users with ACLs a Grid Ê Ê Ê F/ITR - National Virtual Observatory 53,862 9,536,751 1 F - National Partnership for Advanced Computational Infrastructure 36,149 7,539,180 3 tic collections Ğ Hayden planetarium 8, ,352 2 ne Ğ public collections 12,998 6,707,952 F/NPACI - Biology and Environmental collections 40,155 76,083 F/NPACI Ğ Joint Center for Structural Genomics 15,731 1,577,260 F - TeraGrid, ENZO Cosmology simulations 176,730 2,125,945 3,2 - Biomedical Informatics Research Network 10,561 7,596,888 3 ital Library Ê Ê Ê F/NPACI - Long Term Ecological Reserve 256 9,033 F/NPACI - Grid Portal 2,620 53, Alliance for Cell Signaling microarray data ,594 F - National Science Digital Library SIO Explorer collection 2,733 1,083,998 F/ITR - Southern California Earthquake Center 131,010 2,702,421 sistent Archive Ê Ê Ê PRC Persistent Archive Testbed (Kentucky, Ohio, Michigan, Minnesota) ,186 SD Libraries archive 4, ,050 RA- Research Prototype Persistent Archive 1, ,434 F - National Science Digital Library persistent archive 3,600 27,034,150 1 TAL 501 TB 68 million 5,3

15 nfrastructure Independence Data virtualization Management of name spaces independently of the storage repositories Global name spaces Persistent identifiers Collection-based ownership of files Support for access operations independently of the storage repositories Separation of access methods from storage protocols Support for integrity and authenticity operations

16 Separation of Access Method from Storage Protocols Access Method Access Operations Data Grid Storage Operations Storage Protocol Storage System Map from the operations used by the access method to a standard set of operations used to interact with the storage system

17 Data Grid Operations File access Open, close, read, write, seek, stat, synch, Audit, versions, pinning, checksums, synchronize, Parallel I/O and firewall interactions Versions, backups, replicas Latency management Bulk operations Register, load, unload, delete, Remote procedures HDFv5, data filtering, file parsing, replicate, aggregate Metadata management SQL generation, schema extension, XML import and export, browsing, queries, GGF, Operations for Access, Management, and Transport at Remote Sites

18 Latency Management - Bulk Operations Bulk register Create a logical name for a file Load context (metadata) Bulk load Create a copy of the file on a data grid storage repository Bulk unload Provide containers to hold small files and pointers to each file location Bulk delete Trash can Sticky bits for access control,

19 Examples of Extensibility The 3 fundamental APIs are C library, shell commands, Java Other access mechanisms are ported on top of these interfaces API evolution Initial access through C library, Unix shell command Added inq Windows browser (C++ library) Added mysrb Web browser (C library and shell commands) Added Java (Jargon) Added Perl/Python load libraries (shell command) Added WSDL (Java) Added OAI-PMH, OpenDAP, DSpace digital library (Java) Added Kepler actors for dataflow access (Java) Added GridFTP version 3.3 (C library)

20 Examples of Extensibility Storage Repository Driver evolution Initially supported Unix file system Added archival access - UniTree, HPSS Added FTP/HTTP Added database blob access Added database table interface Added Windows file system Added project archives - Dcache, Castor, ADS Added Object Ring Buffer, Datascope Added GridFTP version 3.3 Database management evolution Postgres DB2 Oracle Informix Sybase

21 Logical Name Spaces Data Access Methods (C library, Unix, Web Browser) Storage Repository Storage location User name File name File context (creation date, ) Access constraints Data access directly between application and storage repository using names required by the local repository

22 Logical Name Spaces Data Access Methods (C library, Unix, Web Browser) Data Collection Storage Repository Storage location User name File name File context (creation date, ) Access constraints Data Grid Logical resource name space Logical user name space Logical file name space Logical context (metadata) Control/consistency constraints Data is organized as a shared collection

23 ederation Between Data Grids Data Access Methods (Web Browser, DSpace, OAI-PMH) Data Collection A Data Grid Logical resource name space Logical user name space Logical file name space Logical context (metadata) Data Collection B Data Grid Logical resource name space Logical user name space Logical file name space Logical context (metadata) Control/consistency constraints Control/consistency constraint Access controls and consistency constraints on cross registration of digital entities

24 Types of Federation Peer-to-peer grids Data grids forward requests for access to public data Hierarchical grids Master - slave All files in slave data grid are replicated from the master data grid Central archive Multiple independent data grids deposit replicas into a central archive Replication grids Two independent data grids serve as back-up sites for each other

25 Data Management Systems Digital Libraries DSpace services for ingestion and description of files - ported on top of SRB data grid Fedora relationship management services, port on top of SRB data grid in test Cheshire integration on top of SRB data grid OAI-PMH interface to the SRB data grid Persistent archives Manage authenticity, integrity, and infrastructure independence Integrate preservation processes on top of SRB data grid

26 hronopolis Preservation Facility Demonstrate preservation environment Authenticity Integrity Management of technology evolution Mitigation of risk of data loss Replication of data Federation of catalogs Management of preservation metadata Scalability 3 collections / year Support 100 TBs per site NCAR U Md SDSC MCAT MCAT MCAT Deep Archive at NARA, no user access but complete copy Federation of Three Independent Data Grids Replicated copy at U Md for improved access, load balancing and disaster recovery Active archive at SDSC, user access

27 Distributed Metadata Management Database specific replication Oracle Master-slave catalogs across vendors Synchronize an independent metadata catalog with state from primary catalog SRB version 3.4 Master-slave catalog federation between data grids How to enforce data grid administration policies across independent data grids

28 Data Grids: Third Viewpoint Require ability to apply dynamic consistency constraints to state information When federating data grids When modifying views of collections When managing data placement When asserting global properties (creating consistent state across the collection) Synchronization of replicas Validation of checksums

29 State Information Context Need to be able to characterize the consistency constraints that are evaluated when updating state information Example - copying data Replica (intent that copy be synchronized) Version (intent that copy be labeled) Backup (intent that copy represent time snapshot) New file (intent that copy be independent of original) Could change intent of the copy, changing the required state information

30 Dynamic Constraints Need technology that manages Reification of consistency rules into metadata State information about the reification Version of consistency rules that were evaluated Time stamp for when the evaluation was done Granularity within the collection for which the reification is valid Require two versions Management of procedural execution of rules Management of global consistency assertions

31 Projects Monash University / NSF National Science Digital Library / NARA Persistent Archive Integration of Fedora and SRB data grid SDSC - NSF ITR on Constraint-based Knowledge Systems for Grids, Digital Libraries, and Persistent Archives Embedding of dynamic constraint management within the SRB data grid

32 For More Information Reagan W. Moore San Diego Supercomputer Center