JCDL 2016 Doctoral Consortium - Web Archive Profiling
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Transcript of JCDL 2016 Doctoral Consortium - Web Archive Profiling
Web Archive ProfilingFor
Efficient Memento Aggregation
Sawood AlamOld Dominion University, Norfolk, Virginia - 23529
Advisor: Michael L. Nelson
Doctoral Consortium JCDL’16June 19, 2016
Supported in part by the International Internet Preservation Consortium (IIPC)
Motivation
Motivation
Motivation
Memento Aggregator
Memento Aggregator
Memento Aggregator
Memento Aggregator
Memento Aggregator
Memento Aggregator
From: Michael Nelson [mailto:[email protected]]
Sent: Wednesday, December 02, 2015 12:33 PM
To: Jones, Gina
Cc: Rourke, Patrick; Grotke, Abigail
Subject: Re: WebSciDL
Hi Gina, I'll investigate. memgator is software that one my students wrote, but I suspect the traffic you're seeing is b/c it is deployed in http://oldweb.today/ can you share the IP addr from where you're seeing the traffic? I presume the requests are for Memento TimeMaps? It should not being actually scraping HTML pages.
regards,
Michael
On Wed, 2 Dec 2015, Jones, Gina wrote:
> Hi Michael, we have a slight configuration issue with the current OW
> set up for our webarchives. I think, from looking at the logs, that
> "MemGator:1.0-rc3 <@WebSciDL>" is really causing some issues on our wayback.
> Do you know who is running this scraper? Itʼs not part of memento is it?
>
> Gina Jones
> Web Archiving Team
> Library of Congress
From: Ilya Kreymer <[email protected]>
Date: Wed, 2 Dec 2015 10:33:56 -0800
Subject: high traffic on oldweb!
To: Herbert Van de Sompel <[email protected]>, Sawood Alam <[email protected]>
Hi Herbert, Sawood,
Herbert: Perhaps you are lucky that I am not using the LANL aggregator, as the traffic has gotten really high, and also I was asked to remove an archive due to the traffic it was causing temporarily..
I am thinking that ability to remove source archives quickly is an important aspect of an aggregator.
Sawood: Hopefully yours will support something like this so I don't need to restart the container to change the archivelist ;)
Ilya
Broadcasting is Bad
Availability and Overlap
● Archives are sparse● Broadcasting is wasteful, both clients and archives suffer
Memento Routing
Routing Pros & Cons
● Pros○ Minimizes traffic and resources consumption○ Improves throughput
● Cons○ Upfront profile maintenance cost○ May miss Mementos (false negatives)
Why Small Archives Matter?
Why Small Archives Matter?
● 400B+ web pages at IA do not cover everything
● Top three archives after IA produce full TimeMap 52% of the time (AlSum et al, TPDL 2013)
● Targeted crawls● Special focus archives● Restricted resources● Private archives● Censorship
While the IA was Down...
$ memgator -f cdxj example.org | cut -c-4 | grep -v "^@" | uniq -c 2 2002 1 2005 1 2008 6 2009 67 2010 17 2011 64 2012 108 2013 108 2014 186 2015 51 2016
Research Questions
● What do individual web archives hold?● How much do we need to know about an
archive’s holdings?● What is the optimal level of summarization for
better accuracy and increased freshness?● What are various ways to learn about archives’
holdings?● How to store and update archives’ profiles to
efficiently scale?
Archive Profile
● High-level summary of an archive● Predicts presence of mementos of a URI-R in
an archive● Provides various statistics about the holdings● Small in size● Publicly available● Easy to update and partially patch● Useful for Memento query routing and other
things
Profiling Policies
● Complete URI-R Profiling (1 URI-R = 1 Profile Key)
○ bbc.co.uk/images/logo.png?w=90○ cnn.com/2014/03/15/?id=128734
● TLD-only Profiling (1 TLD = 1 Profile Key)
○ com)/○ uk)/
● Middle Ground○ uk,co)/○ uk,co,bbc)/images○ uk,co,bbc)/0/2/1○ com,cnn)/ 201309 ar
Available Profiling ResourcesClient request
Archive Response
CDX Records
Profiling Strategies
● CDX Profiling● Fulltext Search Profiling● Sample URI Profiling● Response Cache Profiling
Sample Profile
Probability Rank
Archives
Archive URI-Rs URI-Ms Index Size
Archive-It 1.9B 5.3B 1.8TB
UKWA 0.7B 1.7B 0.5TB
Stanford 12M 25M 8.3GB
Sample Query Sets
Sample(1M URIs Each)
InArchive-It
InUKWA
InStanford
Union{AIT, UK,
SU}
DMOZ 4.097% 3.594% 0.034% 7.575%
MementoProxy 4.182% 0.408% 0.046% 4.527%
IAWayback 3.716% 0.519% 0.039% 4.165%
UKWayback 0.108% 0.034% 0.002% 0.134%
Evaluation
● Generate profiles with 23 policies● Relate CDX Size, URI-M, URI-R, and URI-Key● Analyze profile growth● Estimate Relative Cost● Evaluate Routing Efficiency
Resource Requirement
CDX Size vs URI-M (UKWA 10 Years)
Alpha: 175 bytes per CDX line
URI-M vs URI-R (UKWA 10 Years)
Gamma: 2.46 K : 2.686Beta: 0.911
Space Cost (UKWA 7 Years)
Phi: 8.5e-07 -- 0.70583
Time Cost (UKWA 7 Years)
Tau: 5.7e-05 -- 6.2e-05CDX: 45GBURI-Ms: 181MURI-Rs: 96MTime: 3 hours
Archive-It
Fulltext Search Cost
Partial Knowledge
Cost vs Accuracy
Group Policies Cost Accuracy
G1 H1P0/TLD Bound by # of TLDs ≈ 0.01
G2 H3P0, DDom, DSub, DPth, DQry < 0.01 ≈ 0.78
G3 DIni ≈ 2 * G2 ≈ 0.88
G4 HxP1 ≈ 5 * G3 ≈ 0.94
G5 Higher HmPn 0.4 -- 0.7 Not Explored
G6 URIR 1.0 1.0
Work Plan
✓ Baseline Profiling Through CDX Files✓ Profile Serialization✓ Fulltext Search Profiling✓ Sample URI Dataset➢ Instrumenting Memento Aggregator➢ Multidimensional Profiling
Publications
TPDL15 Web Archive Profiling Through CDX Summarization
TCDL15 Profiling Web Archives - For Efficient Memento Query Routing
IJDL16 Web Archive Profiling Through CDX Summarization
JCDL16 Poster: MemGator - A Portable Concurrent Memento Aggregator
TPDL16 Web Archive Profiling Through Fulltext Search
RFC Object Resource Stream (ORS) and CDX-JSON (CDXJ) Formats
C4LJ MemGator - A Portable Concurrent Memento Aggregator Architecture
JCDL17 Scalable, Maintainable, and Extensible Web Archive Profile Serialization for Efficient Lookup
JCDL17 URI, Time, and Language Profiling from Live Archives via URI Sampling and Fulltex Search
SIGIR17 Memento Aggregator Routing Based on Probability Distribution of Memento Availability with Archive Profiles
IJDL17 Archive X-Ray - Web Archive Profiling for Efficient Memento Aggregation
Future Work
● Language profiles● Evaluation of combination profiles such as
URI-Key along with Datetime● Utilize archive profile to generate rank
ordered list of archive● Profiles for usage other than Memento
routing, such as, site classification based profiles (e.g., news, wiki, social media, blog etc.)
Conclusions● Generated profiles with different policies for three archives● Examined cost-precision tradeoffs of various policies● Related CDX Size, URI-M, URI-R, and URI-Key● Gained up to 80% routing accuracy with <1% relative cost
while maintaining 0.9 recall