future of database systems 2: xml databases and grid-based digital libraries
DESCRIPTION
Future of Database Systems 2: XML Databases and Grid-based Digital Libraries. University of California, Berkeley School of Information Management and Systems SIMS 257: Database Management. Lecture Outline. Review Future of Database Systems XML and DBMS Grid-Based Digital Libraries - PowerPoint PPT PresentationTRANSCRIPT
IS 257 – Fall 2005 2005.11.22- SLIDE 1
Future of Database Systems 2: XML Databases and Grid-based Digital
LibrariesUniversity of California, Berkeley
School of Information Management and Systems
SIMS 257: Database Management
IS 257 – Fall 2005 2005.11.22- SLIDE 2
Lecture Outline• Review
– Future of Database Systems• XML and DBMS• Grid-Based Digital Libraries
– Data Grids– Grid-based IR
• DBMS and usability
IS 257 – Fall 2005 2005.11.22- SLIDE 3
Lecture Outline• Review
– Future of Database Systems• XML and DBMS• Grid-Based Digital Libraries
– Data Grids– Grid-based IR
• DBMS and usability
IS 257 – Fall 2005 2005.11.22- SLIDE 4
• Radio has no future, Heavier-than-air flying machines are impossible. X-rays will prove to be a hoax.– William Thompson (Lord Kelvin), 1899
IS 257 – Fall 2005 2005.11.22- SLIDE 5
• This “Telephone” has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us.– Western Union, Internal Memo, 1876
IS 257 – Fall 2005 2005.11.22- SLIDE 6
• I think there is a world market for maybe five computers– Thomas Watson, Chair of IBM, 1943
IS 257 – Fall 2005 2005.11.22- SLIDE 7
• By the turn of this century, we will live in a paperless society.– Roger Smith, Chair of GM, 1986
IS 257 – Fall 2005 2005.11.22- SLIDE 8
• I predict the internet… will go spectacularly supernova and in 1996 catastrophically collapse.– Bob Metcalfe (3-Com founder and inventor of
ethernet), 1995
IS 257 – Fall 2005 2005.11.22- SLIDE 9
Accomplishments of DBMS Research
• DBMS are now used in almost every computing environment to create, organize and maintain large collections of information, and this is largely due to the results of the DBMS research community’s efforts, in particular:– Relational DBMS– Transaction management– Distributed DBMS
IS 257 – Fall 2005 2005.11.22- SLIDE 10
Next Generation Database Systems
• Where are we going from here?– Hardware is getting faster and cheaper– DBMS technology continues to improve and
change• OODBMS• ORDBMS
– Bigger challenges for DBMS technology• Medicine, design, manufacturing, digital libraries,
sciences, environment, planning, etc...
IS 257 – Fall 2005 2005.11.22- SLIDE 11
Examples• NASA EOSDIS
– Estimated 1016 Bytes (Exabyte)• Computer-Aided design• The Human Genome• Department Store tracking
– Mining non-transactional data (e.g. Scientific data, text data?)
• Insurance Company– Multimedia DBMS support
IS 257 – Fall 2005 2005.11.22- SLIDE 12
New Features• New Data types• Rule Processing• New concepts and data models• Problems of Scale• Parallelism/Grid-based DB• Tertiary Storage vs Very Large-Scale Disk
Storage• Heterogeneous Databases• Memory Only DBMS
IS 257 – Fall 2005 2005.11.22- SLIDE 13
Coming to a Database Near You…
• Browsibility• User-defined access methods• Security• Steering Long processes• Federated Databases• IR capabilities• XML• The Semantic Web(?)
IS 257 – Fall 2005 2005.11.22- SLIDE 14
Some things to consider• Bandwidth will keep increasing and getting
cheaper (and go wireless)• Processing power will keep increasing
– Moore’s law: Number of circuits on the most advanced semiconductors doubling every 18 months
• Memory and Storage will keep getting cheaper (and probably smaller)– “Storage law”: Worldwide digital data storage capacity
has doubled every 9 months for the past decade• Put it all together and what do you have?
– “The ideal database machine would have a single infinitely fast processor with infinite memory with infinite bandwidth – and it would be infinitely cheap (free)” : David DeWitt and Jim Gray, 1992
IS 257 – Fall 2005 2005.11.22- SLIDE 15
Lecture Outline• Review
– Future of Database Systems• XML and DBMS• Grid-Based Digital Libraries
– Data Grids– Grid-based IR
• DBMS and usability
IS 257 – Fall 2005 2005.11.22- SLIDE 16
Standards: XML/SQL• As part of SQL3 an extension providing a
mapping from XML to DBMS is being created called XML/SQL
• The (draft) standard is very complex, but the ideas are actually pretty simple
• Suppose we have a table called EMPLOYEE that has columns EMPNO, FIRSTNAME, LASTNAME, BIRTHDATE, SALARY
IS 257 – Fall 2005 2005.11.22- SLIDE 17
Standards: XML/SQL• That table can be mapped to:
<EMPLOYEE> <row><EMPNO>000020</EMPNO> <FIRSTNAME>John</FIRSTNAME> <LASTNAME>Smith</LASTNAME> <BIRTHDATE>1955-08-21</BIRTHDATE> <SALARY>52300.00</SALARY> </row>
<row> … etc. …
IS 257 – Fall 2005 2005.11.22- SLIDE 18
Standards: XML/SQL• In addition the standard says that
XMLSchemas must be generated for each table, and also allows relations to be managed by nesting records from tables in the XML.
• Don’t know whether this has actually been implemented by anyone– There is actually something very similar in the
Cheshire II interface to RDBMS
IS 257 – Fall 2005 2005.11.22- SLIDE 19
Lecture Outline• Review
– Future of Database Systems• XML and DBMS• Grid-Based Digital Libraries
– Data Grids– Grid-based IR
• DBMS and usability
IS 257 – Fall 2005 2005.11.22- SLIDE 20
Grid-based Digital Libraries• So what’s this Grid thing anyhow?• Data Grids and Distributed Storage• Grid-Based IR• Grid-Based Digital Libraries
This lecture borrows heavily from presentations by Ian Foster (Argonne National Laboratory & University of Chicago), Reagan Moore and others from San Diego Supercomputer Center
IS 257 – Fall 2005 2005.11.22- SLIDE 21
The Grid: On-Demand Access to Electricity
Time
Qua
lity,
eco
nom
ies
of s
cale
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 22
By Analogy, A Computing Grid
• Decouples production and consumption– Enable on-demand access– Achieve economies of scale– Enhance consumer flexibility– Enable new devices
• On a variety of scales– Department– Campus– Enterprise– Internet
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 23
Not Exactly a New Idea …• “The time-sharing computer system can
unite a group of investigators …. one can conceive of such a facility as an … intellectual public utility.”– Fernando Corbato and Robert Fano , 1966
• “We will perhaps see the spread of ‘computer utilities’, which, like present electric and telephone utilities, will service individual homes and offices across the country.” Len Kleinrock, 1967
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 24
But, Things are Different Now
• Networks are far faster (and cheaper)– Faster than computer backplanes
• “Computing” is very different than pre-Net– Our “computers” have already disintegrated– E-commerce increases size of demand peaks– Entirely new applications & social structures
• We’ve learned a few things about software
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 25
Computing isn’t Really Like Electricity
• I import electricity but must export data• “Computing” is not interchangeable but highly
heterogeneous: data, sensors, services, …• This complicates things; but also means that the
sum can be greater than the parts – Real opportunity: Construct new capabilities
dynamically from distributed services• Raises three fundamental questions
– Can I really achieve economies of scale?– Can I achieve QoS across distributed services?– Can I identify apps that exploit synergies?
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 26
Why the Grid?(1) Revolution in Science• Pre-Internet
– Theorize &/or experiment, aloneor in small teams; publish paper
• Post-Internet– Construct and mine large databases of
observational or simulation data– Develop simulations & analyses– Access specialized devices remotely– Exchange information within
distributed multidisciplinary teamsSource: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 27
Why the Grid?(2) Revolution in Business• Pre-Internet
– Central data processing facility• Post-Internet
– Enterprise computing is highly distributed, heterogeneous, inter-enterprise (B2B)
– Business processes increasingly computing- & data-rich
– Outsourcing becomes feasible => service providers of various sorts
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 28
New OpportunitiesDemand New Technology
“Resource sharing & coordinated problem solving in dynamic, multi-institutional virtual organizations”
Source: Ian Foster
IS 257 – Fall 2005 2005.11.22- SLIDE 29
Building an Open Grid
IS 257 – Fall 2005 2005.11.22- SLIDE 30
Building an Open Grid
OpenStandards
IS 257 – Fall 2005 2005.11.22- SLIDE 31
Building an Open Grid
OpenStandards
OpenSource
IS 257 – Fall 2005 2005.11.22- SLIDE 32
Building an Open Grid
OpenStandards
OpenSource Open
Infrastructure
IS 257 – Fall 2005 2005.11.22- SLIDE 33
Building an Open Grid
OpenStandards
OpenSource Open
Infrastructure
OpenGrid
IS 257 – Fall 2005 2005.11.22- SLIDE 34
Building an Open Grid
OpenStandards
OpenSource Open
Infrastructure
OpenGrid
IS 257 – Fall 2005 2005.11.22- SLIDE 35
Grids and Open StandardsIn
crea
sed
func
tiona
lity,
stan
dard
izat
ion
Time
Customsolutions
Open GridServices Arch
GGF: OGSI, …(+ OASIS, W3C)
Multiple implementations,including Globus Toolkit
Web services
Globus Toolkit
Defacto standardsGGF: GridFTP, GSI
X.509,LDAP,FTP, …
App-specificServices
IS 257 – Fall 2005 2005.11.22- SLIDE 36
Open Grid Services Architecture
• Service-oriented architecture– Key to virtualization, discovery, composition,
local-remote transparency • Leverage industry standards
– Internet, Web services• Distributed service management
– A “component model for Web services”• A framework for the definition of
composable, interoperable services“The Physiology of the Grid: An Open Grid Services Architecture for
Distributed Systems Integration”, Foster, Kesselman, Nick, Tuecke, 2002
IS 257 – Fall 2005 2005.11.22- SLIDE 37
Realizing a Service-Oriented Architecture: How Do I
• Create, name, manage, discover services?• Render resources, data, sensors as services?• Negotiate service level agreements?• Express & negotiate policy?• Organize & manage service collections?• Establish identity, negotiate authentication?• Manage VO membership & communication?• Compose services efficiently?• Achieve interoperability?
IS 257 – Fall 2005 2005.11.22- SLIDE 38
Web Services • XML-based distributed computing technology• Web service = a server process that exposes typed ports
to the network• Described by the Web Services Definition Language, an
XML document that contains– Type of message(s) the service understands & types of
responses & exceptions it returns– “Methods” bound together as “port types”– Port types bound to protocols as “ports”
• A WSDL document completely defines a service and how to access it
IS 257 – Fall 2005 2005.11.22- SLIDE 39
Open Grid Services Infrastructure
Implementation
Servicedata
element
Other standard interfaces:factory,
notification,collections
Hosting environment/runtime(“C”, J2EE, .NET, …)
Servicedata
element
Servicedata
element
GridService(required)
Dataaccess
Lifetime management• Explicit destruction• Soft-state lifetime
Introspection:• What port types?• What policy?• What state?
Client
Grid ServiceHandle
Grid ServiceReference
handleresolution
IS 257 – Fall 2005 2005.11.22- SLIDE 40
The Gridas Enabler of 21st Century Science• Entirely new approaches to enquiry based
on– Deep analysis of huge quantities of data– Interdisciplinary collaboration– Large-scale simulation– Smart instrumentation
• Enabled by an infrastructure that enables access to, and integration of, resources & services without regard for location
IS 257 – Fall 2005 2005.11.22- SLIDE 41
Grid Infrastructure• Broadly deployed services in support of
fundamental collaborative activities– Formation & operation of virtual organizations– Authentication, authorization, discovery, …
• Services, software, and policies enabling on-demand access to critical resources– Computers, databases, networks, storage, software
services,…• Operational support for 24x7 availability• Integration with campus and commercial
infrastructures
IS 257 – Fall 2005 2005.11.22- SLIDE 42
Tier0/1 facility
Tier2 facility
10 Gbps link
2.5 Gbps link
622 Mbps link
Other link
Tier3 facility
The Foundations are Being Laid
Cambridge
Newcastle
Edinburgh
Oxford
Glasgow
Manchester
Cardiff
Soton
London
Belfast
DL
RAL Hinxton
IS 257 – Fall 2005 2005.11.22- SLIDE 43
Data Grid Problem• “Enable a geographically distributed
community [of thousands] to pool their resources in order to perform sophisticated, computationally intensive analyses on Petabytes of data”
• Note that this problem:– Is common to many areas of science– Overlaps strongly with other Grid problems
IS 257 – Fall 2005 2005.11.22- SLIDE 44
Data Grids forHigh Energy Physics
Tier2 Centre ~1 TIPS
Online System
Offline Processor Farm ~20 TIPS
CERN Computer Centre
FermiLab ~4 TIPSFrance Regional Centre
Italy Regional Centre
Germany Regional Centre
InstituteInstituteInstituteInstitute ~0.25TIPS
Physicist workstations
~100 MBytes/sec
~100 MBytes/sec
~622 Mbits/sec
~1 MBytes/sec
There is a “bunch crossing” every 25 nsecs.
There are 100 “triggers” per second
Each triggered event is ~1 MByte in size
Physicists work on analysis “channels”.
Each institute will have ~10 physicists working on one or more channels; data for these channels should be cached by the institute server
Physics data cache
~PBytes/sec
~622 Mbits/sec or Air Freight (deprecated)
Tier2 Centre ~1 TIPS
Tier2 Centre ~1 TIPS
Tier2 Centre ~1 TIPS
Caltech ~1 TIPS
~622 Mbits/sec
Tier 0Tier 0
Tier 1Tier 1
Tier 2Tier 2
Tier 4Tier 4
1 TIPS is approximately 25,000
SpecInt95 equivalents
Image courtesy Harvey Newman, Caltech
IS 257 – Fall 2005 2005.11.22- SLIDE 45
Data Intensive Issues Include …• Harness [potentially large numbers of]
data, storage, network resources located in distinct administrative domains
• Respect local and global policies governing what can be used for what
• Schedule resources efficiently, again subject to local and global constraints
• Achieve high performance, with respect to both speed and reliability
• Catalog software and virtual data
IS 257 – Fall 2005 2005.11.22- SLIDE 46
Data Intensive Computing and Grids
• The term “Data Grid” is often used– Implies a distinct infrastructure, which it isn’t; but easy
to say • Data-intensive computing shares numerous
requirements with collaboration, instrumentation, computation, …– Security, resource mgt, info services, etc.
• Important to exploit commonalities as very unlikely that multiple infrastructures can be maintained
• Fortunately this seems easy to do!
IS 257 – Fall 2005 2005.11.22- SLIDE 47
Examples ofDesired Data Grid Functionality• High-speed, reliable access to remote data• Automated discovery of “best” copy of data • Manage replication to improve performance• Co-schedule compute, storage, network• “Transparency” wrt delivered performance• Enforce access control on data• Allow representation of “global” resource
allocation policies
IS 257 – Fall 2005 2005.11.22- SLIDE 48
A Model Architecture for Data Grids
Metadata Catalog
Replica Catalog
Tape Library
Disk Cache
Attribute Specification
Logical Collection and Logical File Name
Disk Array Disk Cache
ApplicationReplica Selection
Multiple Locations
NWS
SelectedReplica
GridFTP Control ChannelPerformanceInformation &Predictions
Replica Location 1 Replica Location 2 Replica Location 3
MDS
GridFTPDataChannel
Source: Arcot Rajasekar (SDSC)
IS 257 – Fall 2005 2005.11.22- SLIDE 49
Data Grid Requirements• Seamless access to data and information stored
at local and remote sites• Virtualization of data, collection and meta information • Handle Dataset Scaling – size & number• Integrate Data Collections & Associated Metadata• Handle Multiplicity of Platforms,
Resource & Data Types• Handle Seamless Authentication• Handle Access Control • Provide Auditing Facilities• Handle Legacy Data & Methods
Source: Arcot Rajasekar (SDSC)
IS 257 – Fall 2005 2005.11.22- SLIDE 50
SRB as a Solution
Application
SRB Server
Distributed Storage Resources(database systems, archival storage systems, file systems, ftp, http, …)
MCAT
HRM DB2, Oracle, Illustra, ObjectStore HPSS, ADSM, UniTree UNIX, NTFS, HTTP, FTP
• The Storage Resource Broker is a middleware• It virtualizes resource access• It mediates access to distributed heterogeneous resources• It uses a MetaCATalog to facilitate the brokering• It integrates data and metadata
Source: Arcot Rajasekar (SDSC)
IS 257 – Fall 2005 2005.11.22- SLIDE 51
SRBArchives
HPSS, ADSM,UniTree, DMF
DatabasesDB2, Oracle,
Sybase
File SystemsUnix, NT,Mac OSX
Application
C, C++, Linux I/O
Unix Shell
Dublin Core
Resource,User
User Defined
ApplicationMeta-data
RemoteProxies
DataCutter
Third-partycopy
Java, NTBrowsers
WebPrologPython
MCAT
HRM
Source: Arcot Rajasekar (SDSC)
SDSC Storage Resource Broker & Meta-data Catalog
IS 257 – Fall 2005 2005.11.22- SLIDE 52
SRBMaster
SRB agents
Application
MCAT
(port)
1
2 4
AuthenticationSecure Password,
GSI or SEA
Server spawned 3
Identification & Initialization
Session Established
(Host,port)
CA
3
Source: Arcot Rajasekar (SDSC)
SRB Single SignOn
IS 257 – Fall 2005 2005.11.22- SLIDE 53
SRBserver
SRB agent
SRBserver
Federated SRB Operation
MCAT
Read Application
SRB agent
1
2
34
6
5
Logical NameOr
Attribute Condition
1.Logical-to-Physical mapping2. Identification of Replicas3.Access & Audit Control
Peer-to-peer
Brokering
Server(s) SpawningData
Access
Parallel Data Access
R1R2
5/6
Source: Arcot Rajasekar (SDSC)
IS 257 – Fall 2005 2005.11.22- SLIDE 54
SRB Concepts• Abstraction of User Space
– Single sign-on– Multiple authentication schemes
• certificates, (secure) passwords, tickets, group permissions, roles
• Virtualization of Resources– Resource Location, Type & Access transparency– Logical Resource Definitions - bundling
• Abstraction of Data and Collections– Virtual Collections: Persistent Identifier and Global Name Space– Replication & Segmentation
• Data Discovery – system & application metadata– User-defined Metadata – Structural & Descriptive– Attribute-based Access (path names become irrelevant)
• Uniform Access Methods– APIs, Command Line, GUI Browsers, Web-Access (Portal,WSDL, CGI)– Parallel Access with both Client and Server-driven strategies
Source: Arcot Rajasekar (SDSC)
IS 257 – Fall 2005 2005.11.22- SLIDE 55
OceanStore:Everyone’s data, One big Utility
“The data is just out there”
• Separate information from location– Locality is an only an optimization (an important one!)– Wide-scale coding and replication for durability
• All information is globally identified– Unique identifiers are hashes over names & keys– Single uniform lookup interface replaces: DNS, server
location, data location– No centralized namespace required (such as SDSI)
OStore
Source: John Kubiatowicz (UCB)
IS 257 – Fall 2005 2005.11.22- SLIDE 56
Basic Structure:Irregular Mesh of “Pools” OStore
Source: John Kubiatowicz (UCB)
IS 257 – Fall 2005 2005.11.22- SLIDE 57
Amusing back of the envelope calculation• How many files in the OceanStore?
– Assume 1010 people in world– Say 10,000 files/person (very conservative?)– So 1014 files in OceanStore!
– If 1 gig files (not likely), get 1 mole of files!
• Truly impressive number of elements…• … but small relative to physical constants
– (courtesy Bill Bolotsky, Microsoft)
OStore
Source: John Kubiatowicz (UCB)
IS 257 – Fall 2005 2005.11.22- SLIDE 58
Utility-based Infrastructure
• Service provided by confederation of companies– Monthly fee paid to one service provider– Companies buy and sell capacity from each other
Pac Bell
Sprint
IBMAT&T
CanadianOceanStore
IBM
OStore
Source: John Kubiatowicz (UCB)
IS 257 – Fall 2005 2005.11.22- SLIDE 59
Lecture Outline• Review
– Future of Database Systems• Grid-Based Digital Libraries
– Data Grids– Grid-based IR
• DBMS and usability
IS 257 – Fall 2005 2005.11.22- SLIDE 60
DBMS and Usability• What features would you like to see in
DBMS?
IS 257 – Fall 2005 2005.11.22- SLIDE 61
DBMS and Usability• What do you hate about Database
Management Systems?– From your experiences– In general
• What do you like about Database Management Systems?– From your experience– In general
IS 257 – Fall 2005 2005.11.22- SLIDE 62
Next Week• Workshops to help you develop the final
reports and presentations.