Nutch Change Log

Release 0.7 - 2005-08-17

 1. Added support for "type:" in queries. Search results are limited/qualified
    by mimetype or its primary type or sub type. For example,
    (1) searching with "type:application/pdf" restricts results
    to pages which were identified to be of mimetype "application/pdf".
    (2) with "type:application", nutch will return pages of
    primary type "application".
    (3) with "type:pdf", only pages of sub type "pdf" will be listed.
    (John Xing, 20050120)

 2. Added support for "date:" in queries. Last-Modified is indexed.
    Search results are restricted by lower and upper date (inclusive)
    as date:yyyymmdd-yyyymmdd. For example, date:20040101-20041231
    only returns pages with Last-Modified in year 2004.
    (John Xing, 20050122)

 3. Add URLFilter plugin interface and convert existing url filters into
    plugins. (John Xing, 20050206)

 4. Add UpdateSegmentsFromDb tool, which updates the scores and
    anchors of existing segments with the current values in the web
    db.  This is used by CrawlTool, so that pages are now only fetched
    once per crawl.  (Doug Cutting, 20050221)

 5. Moved code into org.apache.nutch sub-packages.  Changed license to
    Apache 2.0.  Removed jar files whose licenses do not permit
    redistribution by Apache.  Disabled compilation of plugins which
    require these libraries.  (Doug Cutting 20050301)

 6. Index host and title in separate fields.  Host was indexed
    previously only as a part of the URL.  Title was indexed as an
    anchor.  Now boosts for matching these fields may be adjusted
    separately from boosts for matching anchors and url.  Also: move
    site indexing to index-basic plugin to minimize the number of
    times the URL needs to be parsed; and, stop using anchor analyzer
    for anything but anchors.  (Piotr Kosiorowski via Doug Cutting
    20050323)

 7. Add servlet Cached.java that serves cached Content of any mime type.
    Slightly modified are web.xml and cached.jsp.
    (John Xing, 20050401)

 8. Add skipCompressedByteArray() to WritableUtils.java.
    (John Xing, 20050402)

 9. Fixes to jsp and static web pages.  These now use relative links,
    so that the Nutch webapp file can be used in places other than at
    the root.  Also fixed links to the about and help pages.  Bug #32.
    (Jerome Charron via cutting, 20050404)

10. Added some features to DistributedSearch: new segments can be added
    to searchservers without restarting the frontend, defective search
    servers are not queried until tey come back online, watchdog keeps
    an eye for your searchservers and writes simple statistics.
    (Sami Siren, 20050407)
    
11. Fix for bug #4 - Unbalanced quote in query eats all resources.
	(Piotr Kosiorowski, Sami Siren, 20050407)

12. Close Issue #33 - MIME content type detector (using magic char sequences).
    (Jerome Charron and Hari Kodungallur via John Xing, 20050416)

13. Add a servlet that implements A9's OpenSearch RSS web service.
    (cutting, 20050418)

14. Remove references to link analysis from tutorial, and enable
    scoring by link count when generating fetchlists and searching.
    (cutting, 20040419)

15. Make query boosts for host, title, anchor and phrase matches
    configurable.  (Piotr Kosiorowski via cutting, 20050419)

16. Add support for sorting search results and search-time deduping by
    fields other than site.

17. Automatically convert range queries into cached range filters.
    This improves the performance and scalability of, e.g., date range
    searching.

18. Several methods have been renamed due to misspellings.  The old
    methods have been deprecated and will be removed before the 1.0
    release.


Release 0.6

 1. Added clustering-carrot2 plugin, together with introduction of clustering
    api and modification to search jsp. (Dawid Weiss via John Xing, 20040809)

 2. Make a number of changes to NDFS (Nutch Distributed File System)
    to fix bugs, add admin tools, etc.

    Also, modify all command line tools so you can indicate whether to
    use NDFS or the local filesystem.  If you indicate nothing, then
    it defaults to the local fs.

    I've used this to do a 35m page crawl via NDFS, distributed over a
    dozen machines.  (Mike Cafarella)

 3. Add support for BASE tags in HTML.  Outlinks are now correctly
    extracted when a BASE tag is present.  (cutting)

 4. Fix two bugs in result pagination.  When the last hit on a page
    was the last hit overall, the "next" button was sometimes shown
    when the "show all" button should be shown instead.  Also, in
    certain cases, the "show all" button would be shown when the
    "next" button should have been shown.  (cutting)

 5. Add config parameter "indexer.max.tokens" that determines the
    maximum number of tokens indexed per field.  (Andy Hedges via cutting)

 6. Add parser for mp3 files.  (Andy Hedges via cutting)

 7. Add RegexUrlNormalizer.  This is useful for things like stripping
    out session IDs from URLs.  To use it, add values for
    urlnormalizer.class and urlnormalizer.regex.file to your
    nutch-site.xml.  The RegexUrlNormalizer class extends the
    BasicUrlNormalizer, and does basic normalization as well.
    (Luke Baker via cutting)

 8. Added Swedish translation (Stefan Verzel via Sami Siren, 20040910)

 9. Added Polish translation (Andrzej Bialecki, 20040911)
 
10. Added 3 more language profiles to language identifier (ru,hu,pl).
	Other changes to language identifier: Porfiles converted to utf8,
	added some test cases, changed the similarity calculation.
	(Sami Siren, 20040925)

11. Added plugin parse-rtf (Andy Hedges via John Xing, 20040929)

12. Added plugin index-more and more.jsp (John Xing, 20041003)

13. Added "View as Plain Text" feature. A new op OP_PARSETEXT is introduced
    in DistributedSearch.java. text.jsp is added. (John Xing, 20041006)

14. Fixed a bug that fails cached.jsp, explain.jsp, anchors.jsp and text.jsp
    (but not search.jsp) with NullPointerException in distributed search.
    It seems that this bug appears after "hits per site" stuff is added.
    The fix is done in Hit.java, making sure String site is never null.
    Hope this fix not have bad effetct on "hits per site" code.
    (John Xing, 20041006)

15. Fixed a bug that fails fullyDelete() in FileUtil.java for
    LocalFileSystem.java. This bug also exposes possible incompleteness
    of NDFSFile.java, where a few methods are not supported, including
    delete(). Nothing changed in NDFSFile.java though. Leave it for future
    improvement (John Xing, 20041022).

16. Introduced option -noParsing to Fetcher.java and added ParseSegment.java.
    A new status code CANT_PARSE is added to FetcherOutput.java.
    Without option -noParsing , no change in fetcher behavior. With
    option -noParsing, fetcher does crawls only, no parsing is carried out.
    Then, ParseSegment.java should be used to parse in separate pass.
    (John Xing, 20041025)

17. Added ontology plugin. Currently it is used for query refinement, as
    examplified in refine-query-init.jsp and refine-query.jsp. By default,
    query refinement is disabled in search.jsp. Please check
    ./src/plugin/ontology/README.txt for further description.
    Ontology plugin certainly can be used for many other things.
    (Michael J. Pan via John Xing, 20041129)
 
18. Changed fetcher.server.delay to be a float, so that sub-second
    delays can be specified.  (cutting)

19. Added plugin.includes config parameter that determines which
    plugins are included.  By default now only http, html and basic
    indexing and search plugins are enabled, rather than all plugins.
    This should make default performance more predictable and reliable
    going forward. (cutting)

20. Cleaned up some filesystem code, including:

    - Replaced BufferedRandomAccessFile with two simpler utilties,
      NFSDataInputStream and NFSDataOutputStream.

    - Fixed the bug where SequenceFiles were no longer flushed when
      created, so that, when fetches crashed, segments were
      unreadable.  Now segments are always readable after crashes.
      Only the contents of the last buffer is lost.

    - Simplified the FSOutputStream API to not include seek().  We
      should never need that functionality.

    - Simplified LocalFileSystem's implementations of FSInputStream
      and FSOutputStream and optimized FSInputStream.seek().

    (cutting)

21. Fixed BasicUrlNormalizer to better handle relative urls.  The file
    part of a URL is normalized in the following manner:

      1. "/aa/../" will be replaced by "/" This is done step by step until
	 the url doesn´t change anymore. So we ensure, that
	 "/aa/bb/../../" will be replaced by "/", too

      2. leading "/../" will be replaced by "/"

    (Sven Wende via cutting)

22. Fix Page constructors so that next fetch date is less likely to be
    misconstrued as a float.  This patches a problem in WebDBInjector,
    where new pages were added to the db with nextScore set to the
    intended nextFetch date.  This, in turn, confused link analysis.

23. In ndfs code, replace addLocalFile(), putToLocalFile() with
    copyFromLocalFile(), moveFromLocalFile(), copyToLocalFile() and
    moveToLocalFile(). (John Xing, 20041217)

24. Added new config parameter fetcher.threads.per.host.  This is used
    by the Http protocol.  When this is one behavior is as before.
    When this is greater than one then multiple threads are permitted
    to access a host at once.  Note that fetcher.server.delay is no
    longer consistently observed when this is greater than one.
    (Luke Baker via Doug Cutting)

Release 0.5

 1. Changed plugin directory to be a list of directories.

 2. Permit Plugin to be the default plugin implementation.

 3. Added pluggable interface for network protocols in new package
    net.nutch.protocol.  Moved http code from core into a plugin.

 4. Added pluggable interface for content parsing in new package
    net.nutch.parse.  Moved html parsing code from core into a
    plugin.

 5. Fixed a bug in NutchAnalysis where 16-bit characters were not
    processed correctly.

 6. Fixed bug #971731: random summaries on result page.
    (Daniel Naber via cutting)

 7. Made Nutch logo transparent. (Daniel Naber via cutting)

 8. Added file protocol plugin.  (John Xing via cutting)

 9. Added ftp protocol plugin.  (John Xing via cutting)

10. Added pdf and msword parser plugins.  (John Xing via cutting)

11. Added pluggable indexing interface.  By default, url, content,
    anchors and title are indexed, as before, but now one can easily
    alter this to, e.g., index metadata.  A demonstration is provided
    which extracts and indexes Creative Commons license urls. (cutting)

12. Add language identification plugin. 

    The process of identification is as follows:

    1. html (html only, HTML 4.0 "lang" attribute)
    2. meta tags (html only, http-equiv, dc.language)
    3. http header (Content-Language)
    4. if all above fail "statistical analysis"

    1 & 2 are run during the fetching phase and 3 & 4 are run on
    indexing phase.

    Currently supported languages (in "statistical analysis") are
    da,de,el,en,es,fi,fr,it,nl,sv and pt. The corpus used was grabbed
    from http://www.isi.edu/~koehn/europarl/ and the profiles were
    build with tool supplied in patch.

    After indexing the language can be found from field named "lang"

    It's not 100% accurate but it's a start.
    (Sami Siren)

13. Added SegmentMergeTool and "mergesegs" command, to remove
    duplicated or otherwise not used content from several segments and
    joining them together into a single new segment.  The tool also
    optionally performs several other steps required for proper
    operation of Nutch - such as indexing segments, deleting
    duplicates, merging indices, and indexing the new single segment.
    (Andrzej Bialecki)

14. Add the ability to retrieve ParseData of a search hit. ParseData
    contains many valuable properties of a search hit.

    This is required (among others) to properly display the cached
    content because it's not possible to determine the character
    encoding from the output of the getContent() method (which returns
    byte[]). The symptoms are that for HTML pages using non-latin1 or
    non-UTF8 encodings the cached preview will almost certainly look
    broken. Using the attached patch it is possible to determine the
    character encoding from the ParseData (for HTTP: Content-Type
    metadata), and encode the content accordingly. (Andrzej Bialecki)

15. Add a pluggable query interface.  By default, the content, anchor
    and url fields are searched as before.  A sample plugin indexes
    the host name and adds a "site:" keyword to query parsing.

16. Added support for "lang:" in queries.  For example, searching with
    "lang:en" restricts results to pages which were identified to
    be in English.

17. Automatically optimize field queries to use cached Lucene filters.
    This makes, for example, searches restricted by languages or sites
    that are very common much faster.

18. Improved charset handling in jsp pages.  (jshin by cutting)

19. Permit topic filtering when injecting DMOZ pages.  (jshin by cutting)

20. When parsing crawled pages, interpret charset specifications in
    html meta tags.  (jshin by cutting)

21. Added support for "cc:licensed" in queries, which searches for documents
    released under Creative Commons licenses.  Attributes of the
    license may also be queried, with, e.g., "cc:by" for
    attribution-required licenses, "cc:nc" for non-commercial
    licenses, etc.

22. Relative paths named in plugin.folders are now searched for on the
    classpath.  This makes, e.g., deployment in a war file much simpler.

23. Modifications to Fetcher.java.

    1. Make sure it works properly with regard to creation and initialization
    of plugin instances. The problem was that multiple threads race to
    startUp() or shutDown() plugin instances. It was solved by synchronizing
    certain codes in PluginRepository.java and Extension.java.
    (Stefan Groschupf via John Xing)

    2. Added code to explictly shutDown() plugins. Otherwise FetcherThreads
    may never return (quit) if there are still data or other structures
    (e.g., persistent socket connections) associated with plugins. (John Xing)
    
    3. Fixed one type of Fetcher "hang" problems by monitoring named
    FetcherThreads. If all FetcherThreads are gone (finished),
    Fetcher.java is considered done. The problem was: there could be
    runaway threads started by external libs via FetcherThreads.
    Those threads never return, thus keep Fetcher from exiting normally.
    (John Xing)

24. Eliminate excessive hits from sites.  This is done efficiently by
    adding the site name to Hit instances, and, when needed,
    re-querying with too-frequent sites prohibited in the query.


Release 0.4

 1. Http class refactored.  (Kevin Smith via Tom Pierce)

 2. Add Finnish translation. (Sampo Syreeni via Doug Cutting)

 3. Added Japanese translation. (Yukio Andoh via Doug Cutting)

 4. Updated Dutch translation. (Ype Kingma via Doug Cutting)

 5. Initial version of Distributed DB code.  (Mike Cafarella)

 6. Make things more tolerant of crashed fetcher output files.
    (Doug Cutting)

 7. New skin for website. (Frank Henze via Doug Cutting)

 8. Added Spanish translation. (Diego Basch via Doug Cutting)

 9. Add FTP support to fetcher.  (John Xing via Doug Cutting)

10. Added Thai translation. (Pichai Ongvasith via Doug Cutting)

11. Added Robots.txt & throttling support to Fetcher.java.  (Mike
    Cafarella)

12. Added nightly build. (Doug Cutting)

13. Default all link scores to 1.0. (Doug Cutting)

14. Permit one to keep internal links. (Doug Cutting)

15. Fixed dedup to select shortest URL. (Doug Cutting)

16. Changed index merger so that merged index is written to named
    directory, rather than to a generated name in that directory.
    (Doug Cutting)

17. Disable coordination weighting of query clauses and other minor
    scoring improvements. (Doug Cutting)

18. Added a new command, crawl, that constructs a database, injects a
    url file and performs a few rounds of generate/fetch/updatedb.
    This simplifies use for intranet sites.  Changed some defaults to
    be more intranet friendly.  (Doug Cutting)

19. Fixed a bug where Fetcher.java didn't construct correct relative
    links when a page was redirected.  (Doug Cutting)

20. Fixed a query parser problem with lookahead over plusses and minuses.
    (Doug Cutting)

21. Add support for HTTP proxy servers.  (Sami Siren via Doug Cutting)

22. Permit searching while fetching and/or indexing.
    (Sami Siren via Doug Cutting)

23. Fix a bug when throttling is disabled.  (Sami Siren via Doug Cutting)

24. Updated Bahasa Malaysia translation.  (Michael Lim via Doug Cutting)

25. Added Catalan translation.  (Xavier Guardiola via Doug Cutting)

26. Added brazilian portuguese translation.
    (A. Moreir via Doug Cutting)

27. Added a french translation.  (Julien Nioche via Doug Cutting)

28. Updated to Lucene 1.4RC3.  (Doug Cutting)

29. Add capability to boost by link count & use it in crawl tool.
    (Doug Cutting)

30. Added plugin system.  (Stefan Groschupf via Doug Cutting)

31. Add this change log file, for recording significant changes to
    Nutch.  Populate it with changes from the last few months.