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Revision 8 as of 2007-03-29 12:55:53
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Editor: c182011
Revision 9 as of 2009-09-20 23:09:34
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Editor: localhost
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===Problem (exception) / Solution pairs===

P:Not a known field name:DEFAULT

S: Add plugin

  • <property> <name>plugin.includes</name> <value>query-basic|.....

in nutch-default.xml

P: java.lang.NullPointerException at java.io.Reader.(Reader.java:61) ... at org.apache.nutch.analysis.CommonGrams.init(CommonGrams.java:152) at

S: the file common-terms.utf8 needs to be in the right directory (lib | classes?)

  • <property>

    • <name>analysis.common.terms.file</name> <value>common-terms.utf8</value> <description>The name of a file containing a list of common terms

      • that should be indexed in n-grams.


    • </property>

P: Bad mapred.job.tracker: local

S: if you want to run crawl without hdfs you can omit start-all.sh

  • just do " nutch crawl urlsdir "

P: ... getlocalpath NullPointerException

S: check mapred.local.dir and other tmp dirs in nutch-default.xml / hadoop-default.xml

P:extension point: org.apache.nutch.net.URLNormalizer does not exist

S:check your plugins + plugin.includes settings and add urlnormalizer-regex or urlnormalizer-(pass|regex|basic) --- P:java.net.UnknownHostException "hostname"

S: add "hostname" to the /etc/hosts file.

P: ...[null] MalformedUrlException

S: add common-terms.utf8 to nutch dir

P: java.lang.ClassCastException: org.apache.hadoop.io.Text

S: wrong hadoop version / patch http://files.pannous.de/org.rar

P:java.lang.NoSuchMethodError: org.apache.hadoop.io.MapFile $Writer.

S: wrong hadoop version / patch http://files.pannous.de/org.rar

P: NullPointerException when crawling :

S: add to nutch-site.xml: <property>

  • <name>http.agent.name</name> <value>NutchCVS</value> <description>Our HTTP 'User-Agent' request header.</description>


P: java.io.IOException: config()

S: ignore it ! ;)

P: nutch crawl ... Job Failed!

S: manifold. set log4j.properties debug level ! log4j.rootLogger=ALL, stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender

P: No scoring plugins - at least one scoring plugin is required!

S: Add "scoring-opic" to <property> <name>plugin.includes</name>

P: ... java.net.SocketTimeoutException: Accept timed out

S: try using nutch without hdfs / check ports in hadoop file / RPC problems : start crawl without startall.sh ?

P: java.lang.NoClassDefFoundError xyz on windows

S: get rid of spaces in your classpath and path variables !

solved_problems (last edited 2009-09-20 23:09:34 by localhost)