更新 Nutch 指数的最佳方法是什么？答案

【问题标题】：What is the best way to freshen a Nutch index?更新 Nutch 指数的最佳方法是什么？
【发布时间】：2009-03-12 19:59:41
【问题描述】：

我已经有一年左右没有看过 Nutch 了，看起来它已经发生了很大的变化。关于重新抓取的文档不清楚。更新现有 Nutch 索引的最佳方法是什么？

【问题讨论】：

标签： indexing nutch full-text-indexing

【解决方案1】：

此脚本大致基于 Nutch 常见问题解答中的脚本，起初对我不起作用：

#!/bin/sh
#
# Automate crawling my site
#
crawldir=./crawl
urldir=./urls
NUTCH_HOME=${NUTCH_HOME:=.}

nutch=$NUTCH_HOME/bin/nutch

# Make sure the crawl directories exist
mkdir -p $crawldir/crawldb $crawldir/segments $crawldir/linkdb

# Inject the initial urls
$nutch inject $crawldir/crawldb $urldir

depth=1
while(true) ; do
  echo "beginning crawl at depth $depth"
  echo "-generate"
  $nutch generate $crawldir/crawldb $crawldir/segments
  if [ $? -ne 0 ] ; then
    echo "finishing at depth $depth - no more urls"
    break
  fi

  segment=`/bin/ls -rtd $crawldir/segments/*|tail -1`

  echo "$nutch fetch $segment"
  $nutch fetch $segment
  if [ $? -ne 0 ] ; then
    echo "fetch failed at depth $depth, deleting segment"
    rm -rf $segment
    continue;
  fi

  echo "$nutch updatedb $crawldir/crawldb $segment"
  $nutch updatedb $crawldir/crawldb $segment
  depth=`expr $depth + 1`
done

echo "$nutch mergesegs $crawldir/MERGEDsegs $crawldir/segments/*"
$nutch mergesegs $crawldir/MERGEDsegs $crawldir/segments/*
if [ $? -eq 0 ] ; then
  rm -rf $crawldir/segments/*
  mv $crawldir/MERGEDsegs/* $crawldir/segments
  rmdir $crawldir/MERGEDsegs
else
  echo "Something went wrong"
  exit
fi

echo "$nutch invertlinks $crawldir/linkdb -dir $crawldir/segments"
$nutch invertlinks $crawldir/linkdb -dir $crawldir/segments

echo "$nutch index $crawldir/NEWindexes $crawldir/crawldb $crawldir/linkdb $crawldir/segments/*"
$nutch index $crawldir/NEWindexes $crawldir/crawldb $crawldir/linkdb \
$crawldir/segments/*

echo "$nutch dedup $crawldir/NEWindexes"
$nutch dedup $crawldir/NEWindexes

echo "$nutch merge $crawldir/MERGEDindexes $crawldir/NEWindexes"
$nutch merge $crawldir/MERGEDindexes $crawldir/NEWindexes

mv $crawldir/index $crawldir/OLDindexes
mv $crawldir/MERGEDindexes $crawldir/index

【讨论】：

【解决方案2】：

我们将 nutch 与 solr 结合使用。我们的 Nutch 指数约为。 80 MB 包含 5000 个网站。到目前为止，最好的重新抓取方法是删除索引并从头开始创建。

【讨论】：