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https://issues.apache.org/jira/browse/NUTCH-2381?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16939500#comment-16939500
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Sebastian Nagel commented on NUTCH-2381:
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Add to conf/nutch-default.xml or *.template (cf. NUTCH-2732):
{noformat}
<property>
<name>db.signature.text_profile.sec_sort_lex</name>
<value>true</value>
<description>
Whether the TextProfileSignature class should sort words also
lexicographically
to avoid changing signatures due to unstable hash sorting. Default is
`true`,
set to `false` to ensure backward-compatibility with CrawlDbs written by
Nutch
1.15 or prior, see also NUTCH-2381.
</description>
</property>
{noformat}
> In some situations the class TextProfileSignature gives different signatures
> for the same text "profile" page.
> --------------------------------------------------------------------------------------------------------------
>
> Key: NUTCH-2381
> URL: https://issues.apache.org/jira/browse/NUTCH-2381
> Project: Nutch
> Issue Type: Bug
> Components: crawldb
> Affects Versions: 1.13
> Reporter: Rodrigo Joni Sestari
> Assignee: Sebastian Nagel
> Priority: Major
> Labels: signature
> Fix For: 1.16
>
>
> In some situations the class TextProfileSignature gives different signatures
> for the same text "profile" page.
> The method TextProfileSignature.calculate uses a HashMap to salve the tokens,
> after some process, the tokens come sorted by decreasing frequency.
> For some pages like "http://curia.europa.eu/jcms/"; the text "profile" is the
> same but the signature come different for each fetch.
> Its happens because the tokens are sorted only by decreasing frequency.
> Tokens with the same frequency maybe not have the same order in different
> fetchs.
> The HashMap no guarantees as to the order of the map and not guarantee that
> the order will remain constant over time.
> My suggestion is change the methods TokenComparator.compare in order to sort
> by frequency and Name.
> Rodrigo
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