1. WebInfoMall: the Chinese Web Archive how we got started and how it is now Huang Lianen and Li Xiaoming Peking University, China Digital Archive Workshop August 27, 2007, Xian, China Huang Lianen and Li Xiaoming Peking University, China Digital Archive Workshop August 27, 2007, Xian, China

2. Institute of Network Computing and Information Systems Outline  Motivation developed in 2001 2001, I was not able to give an answer when some one asked me what had been on Chinese web 1996. 2001, I was not able to give an answer when some one asked me what had been on Chinese web 1996. 2100, I ’ d like to be able to answer concretely if some one will ask me what were on Chinese web 2001 ? 2100, I ’ d like to be able to answer concretely if some one will ask me what were on Chinese web 2001 ?  Archiving technology For long-term web crawl and store, what technology should be used, especially in a university lab environment ? For long-term web crawl and store, what technology should be used, especially in a university lab environment ?  Exhibition of the archive How do we show the archive to the society ? How do we show the archive to the society ?

3. Institute of Network Computing and Information Systems On the elapsing nature of Web data  Li Xiaoming, “ On the estimation of the number of previous Chinese Web pages ”, Journal of Peking University, Vol.39, No.3, May 2003, 394-398.  As a by-product, we also obtained the result that the time for 50% of current web pages disappearing is about 0.99 year. Observing the elapsing nature, can we archive them before they are gone ?

4. Institute of Network Computing and Information Systems We have some advantage With a search engine, 50% is done ! The system work started in 2001

5. Institute of Network Computing and Information Systems The progress and current status  The crawl started in 2001 and the first batch of data was put on line Jan 18, 2002.  As of today, there is a total repository over 2.5 billion Chinese web pages (different), more precisely, pages crawled from mainland China ’ s web  About 1 million pages incremental every day.  Initially, we used tapes for storage, but changed to hard disks later.  Total online data (compressed) volume ≈ 30TB, with an off line backup.  Spring 2002, “ historical browsing ” was provided; summer 2006, beta test of “ backward browsing ” was tested

6. Institute of Network Computing and Information Systems 示例： InfoMall 界面

7. Institute of Network Computing and Information Systems 示例：输入 www.sina.com.cn

8. Institute of Network Computing and Information Systems 示例： 2002.1.18 新浪 Headquarter of Bin Ladin was bombed.

9. Institute of Network Computing and Information Systems 链接保持 The first air strike in new year, American AF bombed the headquarter of Bin Ladin.

10. Institute of Network Computing and Information Systems 继续保持链接

11. 2002.10.8

12. 2003.9.2

13. 2004.5.28

14. Featured collections: sars

15. Institute of Network Computing and Information Systems Featured collections: the first manned space vehicle

16. Institute of Network Computing and Information Systems We ask three questions:  What’s the use ? Preserving historical information before it ’ s lost Preserving historical information before it ’ s lost Implying great opportunities for deep mining Implying great opportunities for deep mining Providing access to previous information much more convenient than libraries even if they have kept it. Providing access to previous information much more convenient than libraries even if they have kept it.  Can we do it ? (or at least get a pretty good start) “ we ” : a university lab. “ we ” : a university lab.  How we do it ?

17. Institute of Network Computing and Information Systems Can we do it ? (resource requirement)  “ hard ” resource Crawler system: 4 computers of $5,000 each Crawler system: 4 computers of $5,000 each Storage system: about 50 million pages per 1TB, amounts to $4,000. If you need a backup, double the investment. Storage system: about 50 million pages per 1TB, amounts to $4,000. If you need a backup, double the investment. Access web server: $4,000 Access web server: $4,000 Space (not big, but reliable) to put these machines Space (not big, but reliable) to put these machines High speed network connection, ? per month ? High speed network connection, ? per month ?  “ soft ” resource Permission for crawling and keeping Permission for crawling and keeping A staff to handle the daily routine matters A staff to handle the daily routine matters Persistent enthusiasm for this undertaking Persistent enthusiasm for this undertaking

18. Institute of Network Computing and Information Systems How we do it ?  Incremental crawling A scheduled daily operation, collect about one to two million new pages a day, fingerprint compared with previous pages A scheduled daily operation, collect about one to two million new pages a day, fingerprint compared with previous pages  Data storage and incorporation Once a few weeks after having collected enough data Once a few weeks after having collected enough data  Accessibility Wayback machine style Wayback machine style Featured exhibitions Featured exhibitions

19. Institute of Network Computing and Information Systems WebInfoMall: hierarchical module data organization  Assurance of scalability and dynamic re- configurability Convenient for coping with changes at all levels Convenient for coping with changes at all levels record : file : batch : disk : node : system Matching logical data organization with physical devices structure as close as possible

20. Institute of Network Computing and Information Systems The architecture

21. Institute of Network Computing and Information Systems The operations under the hood

22. Institute of Network Computing and Information Systems Comparison  A survey done by National Library of China  Web InfoMall is the only large scale web archive in China – operated in a university lab ! In the flattened world, “small can act big !”

23. Institute of Network Computing and Information Systems Resource sharing   We have published data storage format   And provide WebInfoMall data to research community for free. The beneficiary research units include Peking University, Tsinghua University, Chinese Academy of Sciences, Shanghai Jiaotong University, Renmin Univerisyt of China, Harbin Institue of Technology,....   In particular, we built the largest Chinese Web Test collection with compressed 200GB web pages (CWT200g) for evaluation of Chinese web information retrieval technologies

24. Institute of Network Computing and Information Systems Summary   WebInfoMall, http://www.infomall.cn is the Chinese web archive since 2001, with over 2.5 billion pages in its repository as for 2007.http://www.infomall.cn   Straightforward technology has been used for building WebInfoMall Linux box + Berkeley DB + hierarchical module data organization   We are looking into different ways to access the data to get values more than just information preservation and history browsing

25. Institute of Network Computing and Information Systems Thanks for your attention  lxm@pku.edu.cn