Handle system overview. Digital object architectures

1. Handle System Overview Larry Lannom Corporation for National Research Initiatives http://www.cnri.reston.va.us/

http://www.handle.net/

2.

Digital Object Architecture - Goals
• Framework for managing Digital
(Information) Objects
• Give it a name and talk to it
– Don’t worry about where it is
– Don’t worry about what it’s made of
• Rise above details of application versions
and content formats
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3.

Digital Object Architecture
Client
Repositories / Collections
Resource Discovery
•Search Engines
•Metadata Databases
•Catalogues, Guides, etc.
Resolution System

4. Digital Object Architecture Components Handle System

• Go from name to attributes
• Fundamental indirection system for Digital
Object management on the net
• No free lunch
– Added layer of infrastructure
– Must be managed
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5. Digital Object Architecture Components Repository

• Frees digital content from constraints of
specific technologies
• Provide access across systems, space, time
• No free lunch
– Added layer of infrastructure
– Must be managed
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6. Repository Approach to Interoperability

• Modularization
– Separate raw data (byte stream) from data type
– Separate type definition from type
implementation
• Extensibility
– Create new types on demand
– New components accessible (with controls)
over the network
• Standard access protocol (RAP)
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7. Naming Resources on the Net

The Problem
Internet
www.acme.com
chapter.pdf

8. Naming Resources on the Net

The Solution
Internet
Naming Service
www.acme.com
Name
= Value(s)
10.123/xyz = http://www.acme.com/chapter.pdf
http://www.acme.com/chapter.pdf

9. Naming Resources on the Net

The Solution
www.newbusiness.com
http://www.newbusiness.com/chapter.pdf
Internet
Naming Service
www.acme.com
Name
= Value(s)
10.123/xyz = http://www.newbusiness.com/chapter.pdf

10. CNRI Handle System

• Distributed, scalable, secure
• Enforces unique names
• Enables association of one or more typed values,
e.g., URL, with each name
• Optimized for speed and reliability
• Open, well-defined protocol and data model
• Provides infrastructure for application domains,
e.g., digital libraries, electronic publishing ...
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11. Handle System Implementations

• Library of Congress
• IDF (International DOI Foundation)
–
–
–
–
–
–
–
CrossRef (scholarly journal consortium)
Enpia (Korean content management technology firm)
CDI (U.S. content management technology firm)
LON (U.S. learning object technology firm)
CAL (Copyright Agency Ltd - Australia)
TSO (U.K. publisher & info mgmt service provider)
MEDRA (Multilingual European DOI Registration Agency)
cIDF (Content IDF Forum, based in Japan)
DTIC (Defense Technical Information Center)
NTIS (National Technical Information Service)
Various digital library production and research projects
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12. Handles Resolve to Typed Data

Handle
10.123/456
Data type Index
Handle data
URL
1
http://acme.com/….
URL
2
http://a-books.com/….
DLS
9
acme/repository
HS_ADMIN
XYZ
100
12
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acme.admin/jsmith
1001110011110

13.

The Two Types of Handle Query
1. Request all data
Give me all data associated with handle 10.1000/123.
LHS
Handle
Client
LHS
Handle
10.1000/123
Index Type
3
2
5
10
9
4
URL
URL
URL
PK
EM
IP
GHR
LHS
LHS
LHS
LHS
Data
LHS
URL1(Server in US)
URL2 (Server in Asia)
URL3 (Server in Europe)
public key
email address
rights data
LHS
LHS
Handle System
2. Request all data of a given type
Give me all data of type URL associated with handle 10.1000/123.
LHS
Handle
Client
Handle
10.1000/123
Index Type
3
2
5
URL
URL
URL
Data
URL1(Server in US)
URL2 (Server in Asia)
URL3 (Server in Europe)
LHS
GHR
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

14. Handle Resolution

GHR
LHS
LHS
Client
The Handle System
is a collection of
handle services,
each of which
consists of one or
more replicated sites,
each of which may
have one or more
servers.
LHS
LHS
Site 1
Site 2
Site 2
Site 1
Site 3
…... Site n
#1
#1
#2
#3
#2
#4 ... #n
123.456/abc
URL 4 http://www.acme.com/
URL 8 http://www.ideal.com/

15.

Handle Clients
Request to Client:
Resolve hdl:10.1000/1
1. Sends request to Global to
resolve 0.NA/10.1000
(naming authority
handle for 10.1000)
Client
Global Handle
Registry

16.

Handle Clients
Request to Client:
Resolve hdl:10.1000/1
2. Global Responds with
Service Information for 10.1000
Client
xcccxv
xc
xc
xc
...
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
Service Information
Acme Local Handle Service
Global Handle
Registry

17.

xcccxv
xc
xc
xc
...
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
Handle Clients
IP Address
Port #
Public Key
...
Primary Site
Server 1
123.45.67.8
2641
K03RLQ...
Server 2
123.52.67.9
2641
5&M#FG...
...
...
Server 1
321.54.678.12
2641
F^*JLS...
...
Server 2
321.54.678.14
2641
3E$T%...
...
Server 3
762.34.1.1
2641
A2S4D...
...
123.45.67.4
2641
N0L8H7...
...
Secondary Site A
Secondary Site B
Server 1
Service Information - Acme Local Handle Service

18.

xcccxv
xc
xc
xc
...
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
Handle Clients
IP Address
Port #
Public Key
...
Primary Site
Server 1
123.45.67.8
2641
K03RLQ...
Server 2
123.52.67.9
2641
5&M#FG...
...
...
Server 1
321.54.678.12
2641
F^*JLS...
...
Server 2
321.54.678.14
2641
3E$T%...
...
Server 3
762.34.1.1
2641
A2S4D...
...
123.45.67.4
2641
N0L8H7...
...
Secondary Site A
Secondary Site B
Server 1
Service Information - Acme Local Handle Service

19.

xcccxv
xc
xc
xc
...
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
xcccxv
xccx
xccx
xc
xc
xc
xc
xc
xc
xc
xc
xc
..
..
..
Handle Clients
IP Address
Port #
Public Key
...
Primary Site
Server 1
123.45.67.8
2641
K03RLQ...
Server 2
123.52.67.9
2641
5&M#FG...
...
...
Server 1
321.54.678.12
2641
F^*JLS...
...
Server 2
321.54.678.14
2641
3E$T%...
...
762.34.1.1
2641
A2S4D...
...
123.45.67.4
2641
N0L8H7...
...
Secondary Site A
Server 3
Secondary Site B
Server 1
Service Information - Acme Local Handle Service

20.

Handle Clients
Request to Client:
Resolve hdl:10.1000/1
Client
Global Handle
Registry
3. Client queries Server 3
in Secondary Site A
for 10.1000/1
Acme Local
Handle Service
#1
Secondary Site B
#2
Primary Site
#1
#2
#1
#3
Secondary Site A

21.

Handle Clients
Request to Client:
Resolve hdl:10.1000/1
Global Handle
Registry
Client
4. Server responds with
handle data
Acme Local
Handle Service
#1
Secondary Site B
#2
Primary Site
#1
#2
#1
#3
Secondary Site A

22.

Handle Clients
Handle Administration
Client
Web Client
HTTP Redirect
HTTP Get
http://hdl.handle.net/123.456/abc
Proxy/
Web Server
Handle Data
Resolve
Handle
GHR
LHS
LHS
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

23.

Handle Clients
Client
Plug-In
Handle Administration
Client
Client
hdl:/123.456/abc
Handle Data
Resolve Handle
Request
GHR
LHS
LHS
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

24.

Handle Clients
Handle Administration
Client
Web
HTTP
Web Server
Admin Forms
Handle Admin API
GHR
LHS
LHS
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

25.

Handle Clients
Custom
Client
Handle Administration
Client
Web
GHR
LHS
LHS
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

26.

Handle Clients
Handle Administration
embedded in another
process
Web
GHR
LHS
LHS
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

27.

Handle Clients
Handle Resolution
embedded in another
process
Handle Administration
embedded in another
process
GHR
LHS
LHS
LHS
LHS
LHS
LHS
LHS
LHS
Handle System
LHS

28.

HS Administration
Ownership is at the handle level
Administrators defined by handles
Administrator handles contain keys
All admin transactions validated via
challenge/response from server to client
• Allows distributed administration
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29.

Metadata Collection and DOI Registration
Electronic version of
Advanced Synthesis & Catalysis
published by Wiley Interscience
<doi> 10.XXXX/1234</doi>
<url>http://www3.interscience.wiley.com/…</url>b/
<jname>Advanced Synthesis & Catalysis</jname>
<title>New Horizona</title>
<author>Bill Smith</author>
<page>786-980</page>
<abstract>Lorem ipsum dolor sit amet, consectetuer
elit, sed diem nonummy nibh euismod. Lorem ipsum
dolor sit amet, consectetuer adipiscing elit, sed
diem nonummy nibh euismod</abstract>
Handle Data and Metadata
http://www3.interscience.wiley.com/...
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30.

Metadata Collection and DOI Registration
Handle data and metadata
Metadata
Wholesale
Metadata
Collection
Collection Service
Handle data
• Indexes
• Filters
• Queries
Handle System
Other Data
Services
VARs

31.

Metadata Collection and DOI Registration
Handle data and metadata
Publisher 1
Publisher 2
Publisher 3
Publisher n
Metadata
Wholesale
Metadata
Collection
Collection Service
Handle data
• Indexes
• Filters
• Queries
Handle System
Other Data
Services
VARs

32.

Appropriate Copy Problem
XYZ University
http://dx.doi.org/10.123/456
10.123/456
http://abc.com/article.html
http://abc.com/article.html
dx.doi.org
proxy server
Reference with
DOI for
article.html
in ABC Journal
Handle System
article.html
ABC Journal
publisher
abc.com
Local Copy of
article.html
in ABC Journal

33.

Appropriate Copy Problem: solved
XYZ University
http://dx.doi.org/10.123/456?cookie
Redirect to Local Server
dx.doi.org
proxy server
understands cookies
Reference with
DOI for
article.html
in ABC Journal
Local Server
Handle System
Metadata?
ABC Journal
publisher
abc.com
Metadata
Local Copy of
article.html
in ABC Journal
Metadata
Database

34.

Appropriate Copy Problem
solved w/o local copy
XYZ University
dx.doi.org
proxy server
understands cookies
Reference with
DOI for
article.html
in ABC Journal
Local Server
Handle System
Metadata?
ABC Journal
publisher
article.html abc.com
X
Local Copy of
article.html
in ABC Journal
Metadata
Metadata
Database

35.

Appropriate Copy Problem
extensible solution
XYZ University
http://dx.doi.org/10.123/456?cookie
Redirect to Local Server
dx.doi.org
proxy server
understands cookies
Reference with
DOI for
article.html
in ABC Journal
Handle System
Metadata Location?
Local Server
Meta1.com
ABC Journal
publisher
article.html abc.com
Metadata?
X
Metadata
Local Copy of
article.html
in ABC Journal
Meta1.com
Meta2.com
Meta3.com
Metadata Collection Services

36. Repository Overview

37.

Digital Libraries Without a Digital Object System
HTTP
Web-based
Digital Library
Client
Web Page
HTTP
Other Digital
Library Servers
or Services
Web Page
Web Server
CGI s
Content Operations
(CGI scripts)
Content
Data

38.

Digital Libraries With a Digital Object System
HTTP
Web-based
Digital Library
Client
Other Digital
Library Servers
or Services
Request
Web Page
Web Server
RAP
Dissemination
Request
RAP
Dissemination
D
I
G
I
T
A
L
Content
Data
O
B
J
E
C
T
S
Y
S
T
E
M
Content Operations
(scripts, servlets, other
operations)

39.

Digital Information Object
• Exists within the Digital Object Architecture with the goal of
making information a first class citizen on the Internet.
• Allows high level information to be moved around on the
Internet much as packets of data are today.
•Aggregates relevant heterogeneous data and metadata.
• Solves the who is where problem of network addressing by
using the CNRI Handle System®, a location independent global
naming service.
• Describes the what of information in an concise and
extensible manner.
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40. Digital Information Object Intents of Use

• The Intents of use extensible typing mechanism specifies
what a Digital Information Object contains.
• A specific Digital Information Object’s intent of use is
described as a content type.
• Content types are registered and uniquely identifiable.
• A content type defines a unique set of operations that can be
performed on specific information type.
• The set of operations is known as a content type signature.
• A content type signature can be implemented in different
ways in the form of mobile code called servlets.
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41.

Complex Digital Object Dissemination
.ra
Laptop with modem
.jpg
PDA with wireless
connection
.jpg
.pdf
Digital Phone
.xml
.exe
PC with
T1 Connection
.qt

42.

Digital Object Overview
Information
Content Type(s)
Disseminations
Digital Object
Unique Identifier
Requests

43.

Digital Object Overview
Hamlet
Hamlet
It’s a Book
Get Page(2)

44.

Digital Object Overview
Hamlet
Hamlet
Content Type
Operations
Data
Element
Content Type
Operations
Data
Element
•Digital objects are uniquely identified in a given name space.
•Data elements reference sequences of typed bytes.
•A Digital Object can have zero or more Content Types to reflect
the intents of use of its creator.

45. Digital Object Repository

•Provides distributed Digital Object storage.
Repository
•Behaves as a Digital Object.
•Provides a dynamic acquisition and
execution mechanism for the mobile code
that implements the content type operations.
•Exclusively accessed using the Repository
Access Protocol (RAP).
Deposit
Disseminate
Client

46.

Content Type Extensibility
Type Signature
Type
Signature
Implementation
Content Type
Operations
Servlet
Servlet
Implementation
Servlet API
Services API
1 to many
References
Type Signature API

47.

Content Type Registration
Handle Service
hdl:type/typedef
Register
hdl:type/book
Type
Signature
hdl:type/repository
hdl:type/typeimpl
hdl: type/book
hdl:type/book1
hdl: type/typedef URN hdl: type/repository
hdl: type/book1
Servlet
URN hdl: type/typedef
URN hdl: type/typeimpl
hdl:type/typeimpl URN hdl:type/repository
hdl:type/repository DLS IOR:
URL http://www.type.org

48.

Digital Object Structures
Identifier
Identifier
Identifier
Disseminator
Identifier
Type Signature
Disseminator
Type Signature
Attachments
Servlet
Servlet
hdl:type/repository
signature
Type
Registry
servlet
Handle Service
Attachments
Data
Data
Element Element

49.

Digital Object Structures
Identifier
100.1/PH150
Metadata
Image
Disseminator
Disseminator
100.1/Metadata
100.1/Image
100.1/ImageImplementation
Attachments
hdl:type/repository
Type
Registry
servlet
Attachment
Handle Service
.gif
signature
100.1/MetadataImplementation
.jpg
.txt

50.

Content Type Extensibility Mechanism
Client
C
Identifier
Client
D
Client
A
Identifier
Disseminator
Deposit
Type Signature XYZ
XYZ
Servlet
Client
B
Attachment
XYZ-1
Deposit
Disseminate
Deposit
Data
Element
Data
Element
Repository 2
Repository
Dynamic Acquisition
of Mobile code
XYZ-1

51.

Extensible Dissemination Mechanism
Servlet
Signature API
Servlet API
Repository
Services
Results
Type
Signature
Services API
Extensible Services
Disseminations
Requests
Secure Digital Object Environment
Identifier
Results
Requests
Identifier
Disseminations
Attachments
Disseminator
Type Signature
Servlet
Attachments
Data
Element

52.

Digital Object Chaining
• Provides a building block approach to information
management.
•Enables the creation of information and operation links.
•Content Chaining: a digital object’s data element can
reference its respective content.
•Operations Chaining: servlets can dynamically establish
links to external resources or digital object when executed.
•Content Type Chaining: chaining servlets can be designed
to dynamically build digital object chains from input
parameters.
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53.

Content Chaining Mechanism
Extensible Services
Data
Element
Static
Service
Request
•Type Signature ID
•Servlet ID
•Method Request
•Parameters
Type
Signature
Servlet
or
•Digital Object ID
•Disseminator ID
•Method Request
•Parameters
Digital Object
Typed Bytes

54.

Operation Chaining Mechanism
Extensible Services
Servlet
Services API
Method Request
Dynamic
Service
Request
•Type Signature ID
•Servlet ID
•Method Request
•Parameters
Type
Signature
Servlet
or
•Digital Object ID
•Disseminator ID
•Method Request
•Parameters
Digital Object
Servlet API
self
Digital Object

55.

Digital Object Chaining Example
Example: ask the Babel Fish Object: generate an audio version
of a French translation of Shakespeare's Hamlet.
Babel Fish
Babel Fish
Type
1
8
Audio Tools
Shakespeare
7
4
2
3
Hamlet
5
6
Babel Translator

56.

Data Exchange By Chaining
•Digital Object chaining allows for
homogeneous data exchanges in a
heterogeneous data environment.
•Digital Object Chaining provide a
layer of abstraction over data
formats, encoding and transport
protocols.
Type A
Type A
Type B
Type A
Services
Query System
Type A