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  1. Nutch
  2. NUTCH-1299

LinkRank inverter to ignore records without Node

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Details

    • Bug
    • Status: Closed
    • Major
    • Resolution: Fixed
    • 1.4
    • 1.5
    • None
    • None
    • Patch Available

    Description

      No Node object is passed from the inverter's mapper to the reducer, which expects one, causing the following exception:

      java.lang.NullPointerException
              at org.apache.nutch.scoring.webgraph.LinkRank$Inverter.reduce(LinkRank.java:409)
              at org.apache.nutch.scoring.webgraph.LinkRank$Inverter.reduce(LinkRank.java:356)
              at org.apache.hadoop.mapred.ReduceTask.runOldReducer(ReduceTask.java:519)
              at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:420)
              at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
              at java.security.AccessController.doPrivileged(Native Method)
              at javax.security.auth.Subject.doAs(Subject.java:396)
              at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1083)
              at org.apache.hadoop.mapred.Child.main(Child.java:249)
      

      This never happens unless you have a funky web graph. Our web graph changes frequently, adding and deleting records. It's likely a large number of records deleted from the outlink database is responsible for this. This error, however, only showed up now, a great deal of time after we began deleting records.

      Attachments

        1. NUTCH-1299-1.5-1.patch
          0.9 kB
          Markus Jelsma
        2. NUTCH-1299-1.5-2.patch
          1 kB
          Markus Jelsma

        Activity

          People

            markus17 Markus Jelsma
            markus17 Markus Jelsma
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            Dates

              Created:
              Updated:
              Resolved: