Details

    • Type: Bug
    • Status: Resolved
    • Priority: Blocker
    • Resolution: Fixed
    • Affects Version/s: 1.15
    • Fix Version/s: 1.15
    • Component/s: segment
    • Environment:

      xubuntu 17.10, docker container of apache/nutch LATEST

      Description

      The problem probably occurs since commit https://github.com/apache/nutch/commit/54510e503f7da7301a59f5f0e5bf4509b37d35b4

      How to reproduce:

      • create container from apache/nutch image (latest)
      • open terminal in that container
      • set http.agent.name
      • create crawldir and urls file
      • run bin/nutch inject (bin/nutch inject mycrawl/crawldb urls/urls)
      • run bin/nutch generate (bin/nutch generate mycrawl/crawldb mycrawl/segments 1)
        • this results in a segment (e.g. 20180304134215)
      • run bin/nutch fetch (bin/nutch fetch mycrawl/segments/20180304134215 -threads 2)
      • run bin/nutch parse (bin/nutch parse mycrawl/segments/20180304134215 -threads 2)
        • ls in the segment folder -> existing folders: content, crawl_fetch, crawl_generate, crawl_parse, parse_data, parse_text
      • run bin/nutch updatedb (bin/nutch updatedb mycrawl/crawldb mycrawl/segments/20180304134215)
      • run bin/nutch mergesegs (bin/nutch mergesegs mycrawl/MERGEDsegments mycrawl/segments/* -filter)
        • console output: `SegmentMerger: using segment data from: content crawl_generate crawl_fetch crawl_parse parse_data parse_text`
        • resulting segment: 20180304134535
      • ls in mycrawl/MERGEDsegments/segment/20180304134535 -> only existing folder: crawl_generate
      • run bin/nutch invertlinks (bin/nutch invertlinks mycrawl/linkdb -dir mycrawl/MERGEDsegments) which results in a consequential error
        • console output: `LinkDb: adding segment: file:/root/nutch_source/runtime/local/mycrawl/MERGEDsegments/20180304134535
          LinkDb: org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not exist: file:/root/nutch_source/runtime/local/mycrawl/MERGEDsegments/20180304134535/parse_data
              at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.singleThreadedListStatus(FileInputFormat.java:323)
              at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.listStatus(FileInputFormat.java:265)
              at org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat.listStatus(SequenceFileInputFormat.java:59)
              at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.getSplits(FileInputFormat.java:387)
              at org.apache.hadoop.mapreduce.JobSubmitter.writeNewSplits(JobSubmitter.java:301)
              at org.apache.hadoop.mapreduce.JobSubmitter.writeSplits(JobSubmitter.java:318)
              at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:196)
              at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1290)
              at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1287)
              at java.security.AccessController.doPrivileged(Native Method)
              at javax.security.auth.Subject.doAs(Subject.java:422)
              at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1746)
              at org.apache.hadoop.mapreduce.Job.submit(Job.java:1287)
              at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1308)
              at org.apache.nutch.crawl.LinkDb.invert(LinkDb.java:224)
              at org.apache.nutch.crawl.LinkDb.run(LinkDb.java:353)
              at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
              at org.apache.nutch.crawl.LinkDb.main(LinkDb.java:313)`

      So as it seems mapreduce corrupts the segment folder during mergesegs command.

       

      Pay attention to the fact that this issue is not related on trying to merge a single segment like described above. As you can see on the attached screenshot that problem also appears when executing multiple bin/nutch generate/fetch/parse/updatedb commands before executing mergesegs - resulting in a segment count > 1.

       

        Attachments

        1. Screenshot_2018-03-03_18-09-28.png
          158 kB
          Marco Ebbinghaus
        2. Screenshot_2018-03-07_07-50-05.png
          239 kB
          Marco Ebbinghaus

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              • Assignee:
                lewismc Lewis John McGibbney
                Reporter:
                mebbinghaus Marco Ebbinghaus
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                Dates

                • Created:
                  Updated:
                  Resolved: