Search and Access Technologies for Large Scale Web Archives

Search and Access Technologies for Large Scale

Web ArchivesJoseph JaJa, Sangchul Song, and Mike Smorul

Institute for Advanced Computer StudiesDepartment of Electrical and Computer EngineeringUniversity of MarylandIn Collaboration with the Library of Congress and the Internet Archive

• Web – Main publication/communication medium today, but it is an ephemeral medium.

• Web Archiving:– Capture, annotate, and store important web

contents within their contextual and temporal characteristics;

– Preserve to enable search and access in the long term;

– Unprecedented scale and heterogeneity.

Web Archiving

NDIIPP Partners Meeting 2June 24, 2009

• Discovery of relevant contents based on unstructured queries involving temporal specifications

• Presentation of pertinent summary information in ranked order according to the temporal context

• Scalable search and access performance

Goals


Existing Access Methods

• Chronological Listing Based on URLs– Used by the Wayback Machine of the Internet

Archive, arguably the leader in web archiving.

• Directory Organization– Typically for domain specific contents, which are

organized according to some hierarchical structure.

• Full Text Search– Similar to current web search engines

(NutchWax/WERA)NDIIPP Partners Meeting 4June 24, 2009

Limitations of Current Technologies

• Chronological Listing– Users are expected to provide URLs.

• Hierarchical Listing– Not scalable. Users explore hierarchical

structures, with possibly large numbers of entries.

• Full Text Search (NutchWax/WERA)– Ranking of returned results does not take

temporal context into consideration.– A listing similar to current web search engines.– Lack in performance and scalability.


Issue #1: Scalability and Performance

• For any search time span, the ENTIRE history has to be examined. (Multiple distributed indices can be maintained instead. However, all the indices still need to be searched).

NDIIPP Partners Meeting

time

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Example: Search All, and then Filter

“Find web pages that contain ‘September 11th’ before 2001”

Search all, and then Filter Very inefficient!!

September 11 attacks - Wikipedia, the free encyclopediaThe September 11 attacks (often referred to as nine-eleven, written 9/11) were a series of coordinated suicide attacks by al-Qaeda upon the United States on … en.wikipedia.org/wiki/September_11,_2001_attacks

September 11 Digital ArchiveUses electronic media to collect, preserve, and present the history of the September 11, 2001 attacks in New York, Virginia, and Pennsylvania and the public … 911digitalarchive.org/

9/11 Tributes, September 11 Tributes and Memorials to the Victims …Tributes of 9/11 - September 11th 9/11 memorials. For the Victims their Families and the many Heroes of September 11th. 2001. 9/11 World Trade Center, ... www.jontzen.com/tribute.htm - 132k

National Commission on Terrorist Attacks Upon the United StatesCommission chartered to prepare a full and complete account of the circumstances surrounding the September 11, 2001 terrorist ttacks, … www.9-11commission.gov/ - 8k

… and 4 million other pages pertaining to the September 11th Attack …

September 11 attacks - Wikipedia, the free encyclopediaThe September 11 attacks (often referred to as nine-eleven, written 9/11) were a series of coordinated suicide attacks by al-Qaeda upon the United States on … en.wikipedia.org/wiki/September_11,_2001_attacks

September 11 Digital ArchiveUses electronic media to collect, preserve, and present the history of the September 11, 2001 attacks in New York, Virginia, and Pennsylvania and the public … 911digitalarchive.org/

9/11 Tributes, September 11 Tributes and Memorials to the Victims …Tributes of 9/11 - September 11th 9/11 memorials. For the Victims their Families and the many Heroes of September 11th. 2001. 9/11 World Trade Center, ... www.jontzen.com/tribute.htm - 132k

National Commission on Terrorist Attacks Upon the United StatesCommission chartered to prepare a full and complete account of the circumstances surrounding the September 11, 2001 terrorist ttacks, … www.9-11commission.gov/ - 8k

… and 4 million other pages pertaining to the September 11th Attack …

Ethiopian calendar - Wikipedia, the free encyclopediaThus the first day of the Ethiopian year, 1 Mäskäräm, for years between 1901 and 2099 (inclusive), is usually September 11 (Gregorian), ...en.wikipedia.org/wiki/Ethiopian_calendar - 43k

APOD: September 11, 1997 - Mars Global Surveyor: AerobrakingSeptember 11, 1997 See Explanation. Clicking on the picture will download the highest resolution version available. Mars Global Surveyor: Aerobraking … apod.nasa.gov/apod/ap970911.html - 5k

… and only 630 other pages that are irrelevant to the September 11th Attack

Ethiopian calendar - Wikipedia, the free encyclopediaThus the first day of the Ethiopian year, 1 Mäskäräm, for years between 1901 and 2099 (inclusive), is usually September 11 (Gregorian), ...en.wikipedia.org/wiki/Ethiopian_calendar - 43k

APOD: September 11, 1997 - Mars Global Surveyor: AerobrakingSeptember 11, 1997 See Explanation. Clicking on the picture will download the highest resolution version available. Mars Global Surveyor: Aerobraking … apod.nasa.gov/apod/ap970911.html - 5k

… and only 630 other pages that are irrelevant to the September 11th Attack

4 Million+ pages4 Million+ pages

600+ pages600+ pages

Issue #2: Time-independent Ranking

• Regardless of the search time span, the current ranking schemes always consider the ENTIRE history.

• Meaning and popularity of a term changes over time, and a ranking scheme should be dependent not only on the search terms but also the search time span.


timesearch time span

8June 24, 2009

Issue #3: Ineffective Search Result Delivery

• Search results are usually delivered as a list of URLs, sorted by the relevance ranks.

• No other grouping / sorting options available.


• Ranking that depends on the time span specified by the user.

• Flexible and intuitive presentations of the returned results, ordered according to user’s specification.

• First Step toward Scalable and efficient ‘full text + temporal’ search.

Core Technologies Developed


Scalable & Efficient Temporal Searches


time

time-window

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search time span

For a given search time span, only these two indices are involved.

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Index Distribution and Parallel Search


Search ServerSearch Server

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Search ClusterSearch Cluster

ADAPT Web Archive Search Web Server

Request Broker

Result Aggregator

Web Interface

Web Interface

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Time-dependent Ranking


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search time span

For a given search time span and terms, rankings depend on term popularity during this time span only (rather than the entire time span)

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Search Result Delivery


Grouped by TimeGrouped by Time Grouped by

URLGrouped by URL

Sorted by RelevanceSorted by Relevance

Sorted by TimeSorted by Time

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• Collaboration with the Library of Congress and the Internet Archive.

• US 108th Congress Web Archive:– 16 monthly crawls between December 2003

and March 2005.– Web sites of Representatives, Senators,

Delegates, and Committees of the 108th US Congress (2003-2004).

– Number of sites: 582– Number of records: 27 Millions– Total size around 2TB

• Archived in the Library of Congress

Collection Used


P

ADAPT Web Archive Server

INTERNETINTERNET

UMIACSUMIACS

Search/ReturnRanked URLs Retrieve Web

Documents

Search ClusterSearch Cluster Storage ClusterStorage ClusterProcessing/Indexing

Cluster (Hadoop)Processing/Indexing

Cluster (Hadoop)

WARCs

WARCsWARCs

Library of Congress

Internet Archive

Inverted Indices

StorageContainers

Demo


Screen Shots

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Group by TimeGroup by Time

Search Keywords Time Span

Options

Search Keywords Time Span

Options

Collapse ResultsCollapse Results

Sort by TimeSort by TimeUngroupUngroupSort by RelevanceSort by Relevance

Retrieve PageRetrieve PageFollow LinkFollow Link