Arquivo.pt main goal is the preservation and access of web contents that are no longer available online. During the developing of the PWA IR (information retrieval) system we faced limitations in searching speed, quality of results, scalability and usability. To cope with this, we modified the archive-access project (http://archive-access.sourceforge.net/) to support our web archive IR requirements. Nutchwax, Nutch and Wayback’s code were adapted to meet the requirements. Several optimizations were added, such as simplifications in the way document versions are searched and several bottlenecks were resolved. The PWA search engine is a public service at http://archive.pt and a research platform for web archiving. As it predecessor Nutch, it runs over Hadoop clusters for distributed computing following the map-reduce paradigm. Its major features include fast full-text search, URL search, phrase search, faceted search (date, format, site), and sorting by relevance and date. The PWA search engine is highly scalable and its architecture is flexible enough to enable the deployment of different configurations to respond to the different needs. Currently, it serves an archive collection searchable by full-text with 180 million documents ranging between 1996 and 2010.
Arquivo404 currently defaults to loading the most recent version available on Arquivo.pt . This shouldn't be the case for several reasons:
Often when a website is faced with a 404, it simply redirects the user to the main page, and sometimes the most recent version of a page in Arquivo.pt reflects this behavior. (ex: This Arquivo404 link)
An archive is more valuable the older its preserved contents are, we should give emphasis to the more valuable content and not the more easily available one.
From our own experience, users usually are looking for the older versions of websites, as such this change would improve user experience.
Arquivo404 currently defaults to loading the most recent version available on Arquivo.pt . This shouldn't be the case for several reasons: