Nutch
  1. Nutch
  2. NUTCH-1299

LinkRank inverter to ignore records without Node

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: 1.4
    • Fix Version/s: 1.5
    • Component/s: None
    • Labels:
      None
    • Patch Info:
      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.

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

        Activity

        Hide
        Markus Jelsma added a comment -

        Most likely solution is to check whether a LoopSet enters the reducer without an accompanying Node or LinkDatum object, which are mandatory.

        Show
        Markus Jelsma added a comment - Most likely solution is to check whether a LoopSet enters the reducer without an accompanying Node or LinkDatum object, which are mandatory.
        Hide
        Markus Jelsma added a comment -

        New patch logs warning with proper error message.

        Show
        Markus Jelsma added a comment - New patch logs warning with proper error message.
        Hide
        Markus Jelsma added a comment -

        Superfluous records are now ignored but a WARN message is written to the log.
        Committed for 1.5 in rev. 1297586.

        Show
        Markus Jelsma added a comment - Superfluous records are now ignored but a WARN message is written to the log. Committed for 1.5 in rev. 1297586.
        Hide
        Hudson added a comment -

        Integrated in nutch-trunk-maven #184 (See https://builds.apache.org/job/nutch-trunk-maven/184/)
        NUTCH-1299 LinkRank inverter to ignore records without Node (Revision 1297586)

        Result = SUCCESS
        markus :
        Files :

        • /nutch/trunk/CHANGES.txt
        • /nutch/trunk/src/java/org/apache/nutch/scoring/webgraph/LinkRank.java
        Show
        Hudson added a comment - Integrated in nutch-trunk-maven #184 (See https://builds.apache.org/job/nutch-trunk-maven/184/ ) NUTCH-1299 LinkRank inverter to ignore records without Node (Revision 1297586) Result = SUCCESS markus : Files : /nutch/trunk/CHANGES.txt /nutch/trunk/src/java/org/apache/nutch/scoring/webgraph/LinkRank.java
        Hide
        Hudson added a comment -

        Integrated in Nutch-trunk #1779 (See https://builds.apache.org/job/Nutch-trunk/1779/)
        NUTCH-1299 LinkRank inverter to ignore records without Node (Revision 1297586)

        Result = SUCCESS
        markus : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1297586
        Files :

        • /nutch/trunk/CHANGES.txt
        • /nutch/trunk/src/java/org/apache/nutch/scoring/webgraph/LinkRank.java
        Show
        Hudson added a comment - Integrated in Nutch-trunk #1779 (See https://builds.apache.org/job/Nutch-trunk/1779/ ) NUTCH-1299 LinkRank inverter to ignore records without Node (Revision 1297586) Result = SUCCESS markus : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1297586 Files : /nutch/trunk/CHANGES.txt /nutch/trunk/src/java/org/apache/nutch/scoring/webgraph/LinkRank.java

          People

          • Assignee:
            Markus Jelsma
            Reporter:
            Markus Jelsma
          • Votes:
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            Watchers:
            0 Start watching this issue

            Dates

            • Created:
              Updated:
              Resolved:

              Development