Memento Update CNI Task Force Meeting, Spring 2011 1 Memento Herbert Van de Sompel Robert Sanderson...

Memento UpdateCNI Task Force Meeting, Spring 2011 1

Mementohttp://mementoweb.org/

Herbert Van de Sompel Robert Sanderson

Michael L. Nelson

Giant Leaps Towards Seamless Navigationof the Web of the Past


Overview of Memento Framework

Deployment Progress

Memento and Data

Memento and Discovery

Memento and Branding

Alternative Web Archiving Strategies



Progress

Memento and Data





Memento wants to make it easy

to access the Web of the Past.


Tate OnlineToday

Select DateMarch 16 2008

Tate OnlineMarch 16 2008

FromNational Archives


Tate OnlineToday

Select DateMarch 16 2008

Tate OnlineMarch 16 2008

FromNational Archives

Dynamic Static


Memento achieves this by introducing

a uniform version access capability to

integrate the present and past Web.


Content Management Systems:

• Designed to be aware of all versions of a resource

• Self-contained

• Variety of proprietary version mechanisms

• Versions interlinked using proprietary mechanisms

• Dynamism is managed


World Wide Web:

• Designed to forget about prior versions of a resource

• Distributed

• Dynamism from a management perspective is ignored


There are resource versions on the Web:

• Content management systems

• Web archives

• Transactional archives

• Search engine caches


But the Web architecture has a hard time dealing with them:

• Cannot talk about a resource as it used to exist

• Cannot access a prior version knowing the current one

• Cannot access the current version knowing a prior one

Current approaches are ad hoc and localized


Memento:

• Regards the Web as a big Content Management System

• Introduces a uniform capability to access versions on the Web

• Does not build new archives but leverages all systems that host versions: Web archives, Content Management Systems, Software Version Systems, etc.


Memento’s version access approach:

• Is distributed: versions may exist on several servers

• Uses time as a global version indicator

• Is based on the primitives of the Web: resource, resource state, representation, content negotiation, link


Original Resource and Versions


Bridge from Present to Past


Bridge from Past to Present


Memento Framework


Multiple Archives


Memento Client-Server Interaction



Deployment Progress

Memento and Data





Significant progress has been made towards

seamless navigation of the Web of the Past.


Standardization

• Standardization process started via the IETF

• Interest from IETF and W3C

• Encouraged by major Web architects, including: Tim Berners-Lee, Mark Nottingham, Michael Hausenblas

https://datatracker.ietf.org/doc/draft-vandesompel-memento/


Memento Clients

• Several client tools developed by us and others

• Add-ons for FireFox (operational) and Internet Explorer (experimental)

• Applications for Android (operational) and iPhone/iPad (in development)

• Paper in next issue ofCode4Lib Journal

http://www.mementoweb.org/tools/


Memento Server Support (1)

• Memento-compliant Wayback software:• Used by Internet Archive

• Available to Web archives, worldwide

• Please have your favorite Web Archive install this new version 1.6!



Memento Server Support (2)

• Plug-in for MediaWiki (operational)

• Used on W3C’s main wiki

• Please install it for your MediaWiki!



Memento Server Validator

• Server side client:• Attempts to perform all

Memento actions against a given URI

• Reports success/failure of the interactions and warnings for optional aspects

• Kept up to date with IETF Internet Draft



Memento Proxy Support

• Several systems that host Mementos made Memento-compliant “by proxy”:

• All major Web Archives that do not yet run Memento-compliant Wayback software

• 3,000+ MediaWiki systems, including Wikipedia

• We want all of these to become natively Memento compliant!


Memento Website

• Ongoing effort to add materials that support understanding and adoption:• Introduction to Memento• How to recognize

Mementos, TimeGates, Original Resources?

• Guidelines for servers that host Mementos (Web Archives, CMS, snapshot archives, etc.)

http://www.mementoweb.org/guide/


Funding

• 2007-2010: US $250K grant from Library of Congress

• Approx. 50K on Memento

• 2010-2011: US $1 Million follow-up grant from Library of Congress

• For: Specification, outreach, tool development, further research



Deployment Progress

Memento and Data





Memento Time Travel is really powerful.

Time-Series Data via HTTP follow-your-nose.


Memento Framework


Original Resource: http://lanlsource.lanl.gov/pics/picoftheday.png

Time Series for Humans


Data collected through HTTP Navigation

Time Travel across versions of a Picture of the Day


Thanks Christine!

time

change

Data

time

Process

time

Reproducibility

But if we had static, discoverable snapshots of the data and the process…


Original Resource: http://dbpedia.org/resource/France

Time Series for Machines


Data collected through HTTP Navigationpaper at http://arxiv.org/abs/1003.3661

Time Travel across versions of DBPedia



Deployment Progress

Memento and Data





Very few Web sites provide a “timegate” link.

Need additional mechanisms to support Discovery.


Batch discovery of Mementos: TimeMaps

A TimeMap minimally lists:

• URI and datetime of Mementos known to an archive• URI of Original Resource

TimeMaps can be aggregated across systems that host Mementos


Batch discovery of Mementos: Feed of TimeMaps

• System that host Mementos exposes Feed (e.g. Atom) of TimeMaps to allow applications to remain in sync with its evolving Memento collection:

• One Atom entry per Original Resource for which system hosts Mementos• The entry provides a “timemap” link to a TimeMap for the Original Resource• The datetime value of the updated field of the entry changes when additional Memento for Original Resource becomes available (i.e. TimeMap changes)• The ID of the entry is a tag URI based on URI of Original Resource

Will be proposed to IIPC


Batch discovery of Mementos: robots.txt

• robots.txt file is used by Web servers to convey crawling policies

• Add a directive to support discovery of Mementos known to the server:

• Pointer to a single Memento can suffice as the robot can crawl on from there• Mementos allow for discovery of TimeMaps via HTTP links• e.g. jcdl.org hosts snapshot archives of prior JCDL conferences and adds the following to its robots.txt

Memento: jcdl.org/archive/2002/index.html

Will be promoted via Internet Draft



Deployment Progress

Memento and Data





Memento can recreate pages using resources from different archives.

This poses a branding challenge.


Current Branding Practice for Web Archives

Page and embedded resources from same Web Archive

Brandingfor

pageand

embedded resources


Branding for Web Archives in Memento Mode

Will be researched

Page and embedded resources from various Web Archives

Page branding

Nobranding

Nobranding



Deployment Progress

Memento and Data





Crawl-based Archives host distinct observations.

Transactional Archives never miss an update.


Crawl-Based Web Archives

Observations

For example: Heritrix crawler for Internet Archive


Server-Side Transactional Web Archives

Change History

For example: TTApache, PageVault, Vignette Web Capture


Development of Transactional Web Archive Software

Submit:• Java-Grizzly-Jersey submission interface application• Berkeley DB metadata store• FS store for body and headers

Capture:• Apache connection filter module (mod_ta) captures URI, headers, body• Module POSTs in real-time to transactional archive’s Submit URI


Development of Transactional Web Archive Software

Development timeline:• Ongoing development (LANL) and testing (ODU)• Submit/Access finalized; development focus on collection management• Expected release as open source, 3rd Quarter 2011

Access:• Transactional archive natively supports Memento• Immediate availability of archived content• Export of WARC, e.g. for long-term archiving in other environment


Mementohttp://mementoweb.org/

Herbert Van de SompelRobert SandersonMichael L. Nelson

Giant Leaps Towards Seamless Navigation of the Web of the Past

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