[jira] [Created] (NUTCH-2851) Random object created and used only once

["Lewis John McGibbney (Jira)" <ji...@apache.org>]

Lewis John McGibbney created NUTCH-2851:
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             Summary: Random object created and used only once
                 Key: NUTCH-2851
                 URL: https://issues.apache.org/jira/browse/NUTCH-2851
             Project: Nutch
          Issue Type: Sub-task
          Components: dmoz, generator, indexer, segment
    Affects Versions: 1.18
            Reporter: Lewis John McGibbney
            Assignee: Lewis John McGibbney
             Fix For: 1.19



In class org.apache.nutch.crawl.Generator
In method org.apache.nutch.crawl.Generator.partitionSegment(Path, Path, int)
Called method java.util.Random.nextInt()
At Generator.java:[line 1016]
Random object created and used only once in org.apache.nutch.crawl.Generator.partitionSegment(Path, Path, int)

This code creates a java.util.Random object, uses it to generate one random number, and then discards the Random object. This produces mediocre quality random numbers and is inefficient. If possible, rewrite the code so that the Random object is created once and saved, and each time a new random number is required invoke a method on the existing Random object to obtain it.

If it is important that the generated Random numbers not be guessable, you must not create a new Random for each random number; the values are too easily guessable. You should strongly consider using a java.security.SecureRandom instead (and avoid allocating a new SecureRandom for each random number needed).

This bad practice also affects the following

org.apache.nutch.indexer.IndexingJob since first historized release
org.apache.nutch.segment.SegmentReader since first historized release
org.apache.nutch.tools.DmozParser$RDFProcessor since first historized release 



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