--------------------
1. Nutch是什麼?
Nutch是一個開源的網頁抓取工具,主要用於收集網頁數據,然後對其進行分析,建立索引,以提供相應的接口來對其網頁數據進行查詢的一套工具。其底層使用了Hadoop來做分佈式計算與存儲,索引使用了Solr分佈式索引框架來做,Solr是一個開源的全文索引框架,從Nutch 1.3開始,其集成了這個索引架構2. 在哪裏要可以下載到最新的Nutch?
在下面地址中可以下載到最新的Nutch 1.3二進制包和源代碼http://mirror.bjtu.edu.cn/apache//nutch/
3. 如何配置Nutch?
3.1 對下載後的壓縮包進行解壓,然後cd $HOME/nutch-1.3/runtime/local
3.2 配置bin/nutch這個文件的權限,使用chmod +x bin/nutch
3.3 配置JAVA_HOME,使用export JAVA_HOME=$PATH
4. 抓取前要做什麼準備工作?
4.1 配置http.agent.name這個屬性,如下
- <PRE class=html name="code"><property>
- <name>http.agent.name</name>
- <value>My Nutch Spider</value>
- </property></PRE><BR>
- <BR>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <property>
- <name>http.agent.name</name>
- <value>My Nutch Spider</value>
- </property>
4.2 建立一個地址目錄,mkdir -p urls
在這個目錄中建立一個url文件,寫上一些url,如
- http://nutch.apache.org/
http://nutch.apache.org/
4.3 然後運行如下命令
- bin/nutch crawl urls -dir crawl -depth 3 -topN 5
bin/nutch crawl urls -dir crawl -depth 3 -topN 5
注意,這裏是不帶索引的,如果要對抓取的數據建立索引,運行如下命令
- bin/nutch crawl urls -solr http://localhost:8983/solr/ -depth 3 -topN 5
bin/nutch crawl urls -solr http://localhost:8983/solr/ -depth 3 -topN 5
5. Nutch的抓取流程是什麼樣子的?
5.1 初始化crawlDb,注入初始url
- <PRE class=html name="code">bin/nutch inject
- Usage: Injector <crawldb> <url_dir></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- bin/nutch inject
- Usage: Injector <crawldb> <url_dir>
在我本地運行這個命令後的輸出結果如下:
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch inject db/crawldb urls/
- Injector: starting at 2011-08-22 10:50:01
- Injector: crawlDb: db/crawldb
- Injector: urlDir: urls
- Injector: Converting injected urls to crawl db entries.
- Injector: Merging injected urls into crawl db.
- Injector: finished at 2011-08-22 10:50:05, elapsed: 00:00:03
lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch inject db/crawldb urls/
Injector: starting at 2011-08-22 10:50:01
Injector: crawlDb: db/crawldb
Injector: urlDir: urls
Injector: Converting injected urls to crawl db entries.
Injector: Merging injected urls into crawl db.
Injector: finished at 2011-08-22 10:50:05, elapsed: 00:00:03
5.2 產生新的抓取urls
- bin/nutch generate
- Usage: Generator <crawldb> <segments_dir> [-force] [-topN N] [-numFetchers numFetchers] [-adddays numDays] [-noFilter] [-noNorm][-maxNumSegments num]
bin/nutch generate
Usage: Generator <crawldb> <segments_dir> [-force] [-topN N] [-numFetchers numFetchers] [-adddays numDays] [-noFilter] [-noNorm][-maxNumSegments num]
本機輸出結果如下:
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch generate db/crawldb/ db/segments
- Generator: starting at 2011-08-22 10:52:41
- Generator: Selecting best-scoring urls due for fetch.
- Generator: filtering: true
- Generator: normalizing: true
- Generator: jobtracker is 'local', generating exactly one partition.
- Generator: Partitioning selected urls for politeness.
- Generator: segment: db/segments/20110822105243 // 這裏會產生一個新的segment
- Generator: finished at 2011-08-22 10:52:44, elapsed: 00:00:03
lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch generate db/crawldb/ db/segments
Generator: starting at 2011-08-22 10:52:41
Generator: Selecting best-scoring urls due for fetch.
Generator: filtering: true
Generator: normalizing: true
Generator: jobtracker is 'local', generating exactly one partition.
Generator: Partitioning selected urls for politeness.
Generator: segment: db/segments/20110822105243 // 這裏會產生一個新的segment
Generator: finished at 2011-08-22 10:52:44, elapsed: 00:00:03
5.3 對上面產生的url進行抓取
- bin/nutch fetch
- Usage: Fetcher <segment> [-threads n] [-noParsing]
bin/nutch fetch
Usage: Fetcher <segment> [-threads n] [-noParsing]
這裏是本地的輸出結果:
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch fetch db/segments/20110822105243/
- Fetcher: Your 'http.agent.name' value should be listed first in 'http.robots.agents' property.
- Fetcher: starting at 2011-08-22 10:56:07
- Fetcher: segment: db/segments/20110822105243
- Fetcher: threads: 10
- QueueFeeder finished: total 1 records + hit by time limit :0
- fetching http://www.baidu.com/
- -finishing thread FetcherThread, activeThreads=1
- -finishing thread FetcherThread, activeThreads=
- -finishing thread FetcherThread, activeThreads=1
- -finishing thread FetcherThread, activeThreads=1
- -finishing thread FetcherThread, activeThreads=0
- -activeThreads=0, spinWaiting=0, fetchQueues.totalSize=0
- -activeThreads=0
- Fetcher: finished at 2011-08-22 10:56:09, elapsed: 00:00:02
lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch fetch db/segments/20110822105243/
Fetcher: Your 'http.agent.name' value should be listed first in 'http.robots.agents' property.
Fetcher: starting at 2011-08-22 10:56:07
Fetcher: segment: db/segments/20110822105243
Fetcher: threads: 10
QueueFeeder finished: total 1 records + hit by time limit :0
fetching http://www.baidu.com/
-finishing thread FetcherThread, activeThreads=1
-finishing thread FetcherThread, activeThreads=
-finishing thread FetcherThread, activeThreads=1
-finishing thread FetcherThread, activeThreads=1
-finishing thread FetcherThread, activeThreads=0
-activeThreads=0, spinWaiting=0, fetchQueues.totalSize=0
-activeThreads=0
Fetcher: finished at 2011-08-22 10:56:09, elapsed: 00:00:02
我們來看一下這裏的segment目錄結構
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ ls db/segments/20110822105243/
- content crawl_fetch crawl_generate
lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ ls db/segments/20110822105243/
content crawl_fetch crawl_generate
5.4 對上面的結果進行解析
- <PRE class=html name="code">bin/nutch parse
- Usage: ParseSegment segment</PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- bin/nutch parse
- Usage: ParseSegment segment
本機輸出結果:
- <PRE class=html name="code">lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch parse db/segments/20110822105243/
- ParseSegment: starting at 2011-08-22 10:58:19
- ParseSegment: segment: db/segments/20110822105243
- ParseSegment: finished at 2011-08-22 10:58:22, elapsed: 00:00:02</PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch parse db/segments/20110822105243/
- ParseSegment: starting at 2011-08-22 10:58:19
- ParseSegment: segment: db/segments/20110822105243
- ParseSegment: finished at 2011-08-22 10:58:22, elapsed: 00:00:02
我們再來看一下解析後的目錄結構
- <PRE class=html name="code">lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ ls db/segments/20110822105243/
- content crawl_fetch crawl_generate crawl_parse parse_data parse_text</PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ ls db/segments/20110822105243/
- content crawl_fetch crawl_generate crawl_parse parse_data parse_text
這裏多了三個解析後的目錄。
5.5 更新外鏈接數據庫
- bin/nutch updatedb
- Usage: CrawlDb <crawldb> (-dir <segments> | <seg1> <seg2> ...) [-force] [-normalize] [-filter] [-noAdditions]
bin/nutch updatedb
Usage: CrawlDb <crawldb> (-dir <segments> | <seg1> <seg2> ...) [-force] [-normalize] [-filter] [-noAdditions]
本機輸出結果:
- <PRE class=html name="code">lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch updatedb db/crawldb/ -dir db/segments/
- CrawlDb update: starting at 2011-08-22 11:00:09
- CrawlDb update: db: db/crawldb
- CrawlDb update: segments: [file:/home/lemo/Workspace/java/Apache/Nutch/nutch-1.3/db/segments/20110822105243]
- CrawlDb update: additions allowed: true
- CrawlDb update: URL normalizing: false
- CrawlDb update: URL filtering: false
- CrawlDb update: Merging segment data into db.
- CrawlDb update: finished at 2011-08-22 11:00:10, elapsed: 00:00:01</PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch updatedb db/crawldb/ -dir db/segments/
- CrawlDb update: starting at 2011-08-22 11:00:09
- CrawlDb update: db: db/crawldb
- CrawlDb update: segments: [file:/home/lemo/Workspace/java/Apache/Nutch/nutch-1.3/db/segments/20110822105243]
- CrawlDb update: additions allowed: true
- CrawlDb update: URL normalizing: false
- CrawlDb update: URL filtering: false
- CrawlDb update: Merging segment data into db.
- CrawlDb update: finished at 2011-08-22 11:00:10, elapsed: 00:00:01
這時它會更新crawldb鏈接庫,這裏是放在文件系統中的,像taobao抓取程序的鏈接庫是用redis來做的,一種key-value形式的NoSql數據庫。
5.6 計算反向鏈接
- <PRE class=html name="code">bin/nutch invertlinks
- Usage: LinkDb <linkdb> (-dir <segmentsDir> | <seg1> <seg2> ...) [-force] [-noNormalize] [-noFilter]</PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- bin/nutch invertlinks
- Usage: LinkDb <linkdb> (-dir <segmentsDir> | <seg1> <seg2> ...) [-force] [-noNormalize] [-noFilter]
本地輸出結果:
- <PRE class=html name="code">lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch invertlinks db/linkdb -dir db/segments/
- LinkDb: starting at 2011-08-22 11:02:49
- LinkDb: linkdb: db/linkdb
- LinkDb: URL normalize: true
- LinkDb: URL filter: true
- LinkDb: adding segment: file:/home/lemo/Workspace/java/Apache/Nutch/nutch-1.3/db/segments/20110822105243
- LinkDb: finished at 2011-08-22 11:02:50, elapsed: 00:00:01</PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch invertlinks db/linkdb -dir db/segments/
- LinkDb: starting at 2011-08-22 11:02:49
- LinkDb: linkdb: db/linkdb
- LinkDb: URL normalize: true
- LinkDb: URL filter: true
- LinkDb: adding segment: file:/home/lemo/Workspace/java/Apache/Nutch/nutch-1.3/db/segments/20110822105243
- LinkDb: finished at 2011-08-22 11:02:50, elapsed: 00:00:01
5.7 使用Solr爲抓取的內容建立索引
- bin/nutch solrindex
- Usage: SolrIndexer <solr url> <crawldb> <linkdb> (<segment> ... | -dir <segments>
bin/nutch solrindex
Usage: SolrIndexer <solr url> <crawldb> <linkdb> (<segment> ... | -dir <segments>
Nutch端的輸出如下:
- lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch solrindex http://127.0.0.1:8983/solr/ db/crawldb/ db/linkdb/ db/segments/*
lemo@debian:~/Workspace/java/Apache/Nutch/nutch-1.3$ bin/nutch solrindex http://127.0.0.1:8983/solr/ db/crawldb/ db/linkdb/ db/segments/*
- SolrIndexer: starting at 2011-08-22 11:05:33
SolrIndexer: starting at 2011-08-22 11:05:33
- SolrIndexer: finished at 2011-08-22 11:05:35, elapsed: 00:00:02
SolrIndexer: finished at 2011-08-22 11:05:35, elapsed: 00:00:02
Solr端的部分輸出如下:
- INFO: SolrDeletionPolicy.onInit: commits:num=1
- commit{dir=/home/lemo/Workspace/java/Apache/Solr/apache-solr-3.3.0/example/solr/data/index,segFN=segments_1,version=1314024228223,generation=1,filenames=[segments_1]
- Aug 22, 2011 11:05:35 AM org.apache.solr.core.SolrDeletionPolicy updateCommits
- INFO: newest commit = 1314024228223
- Aug 22, 2011 11:05:35 AM org.apache.solr.update.processor.LogUpdateProcessor finish
- INFO: {add=[http://www.baidu.com/]} 0 183
- Aug 22, 2011 11:05:35 AM org.apache.solr.core.SolrCore execute
- INFO: [] webapp=/solr path=/update params={wt=javabin&version=2} status=0 QTime=183
- Aug 22, 2011 11:05:35 AM org.apache.solr.update.DirectUpdateHandler2 commit
- INFO: start commit(optimize=false,waitFlush=true,waitSearcher=true,expungeDeletes=false)
INFO: SolrDeletionPolicy.onInit: commits:num=1
commit{dir=/home/lemo/Workspace/java/Apache/Solr/apache-solr-3.3.0/example/solr/data/index,segFN=segments_1,version=1314024228223,generation=1,filenames=[segments_1]
Aug 22, 2011 11:05:35 AM org.apache.solr.core.SolrDeletionPolicy updateCommits
INFO: newest commit = 1314024228223
Aug 22, 2011 11:05:35 AM org.apache.solr.update.processor.LogUpdateProcessor finish
INFO: {add=[http://www.baidu.com/]} 0 183
Aug 22, 2011 11:05:35 AM org.apache.solr.core.SolrCore execute
INFO: [] webapp=/solr path=/update params={wt=javabin&version=2} status=0 QTime=183
Aug 22, 2011 11:05:35 AM org.apache.solr.update.DirectUpdateHandler2 commit
INFO: start commit(optimize=false,waitFlush=true,waitSearcher=true,expungeDeletes=false)
5.8 在Solr的客戶端查詢
在瀏覽器中輸入
- http://localhost:8983/solr/admin/
http://localhost:8983/solr/admin/
查詢條件爲baidu
輸出的XML結構爲
如果你要以HTML結構顯示把Solr的配置文件solrconfig.xml中的content改爲如下就可以
<field name="content" type="text" stored="true" indexed="true"/>
- <PRE class=html name="code"><response>
- <lst name="responseHeader">
- <int name="status">0</int>
- <int name="QTime">0</int>
- <lst name="params">
- <str name="indent">on</str>
- <str name="start">0</str>
- <str name="q">baidu</str>
- <str name="version">2.2</str>
- <str name="rows">10</str>
- </lst>
- </lst>
- <result name="response" numFound="1" start="0">
- <doc>
- <float name="boost">1.0660036</float>
- <str name="digest">7be5cfd6da4a058001300b21d7d96b0f</str>
- <str name="id">http://www.baidu.com/</str>
- <str name="segment">20110822105243</str>
- <str name="title">百度一下,你就知道</str>
- <date name="tstamp">2011-08-22T14:56:09.194Z</date>
- <str name="url">http://www.baidu.com/</str>
- </doc>
- </result>
- </response>
- </PRE><BR>
- <PRE></PRE>
- <PRE class=html name="code" sizcache="0" sizset="68"><PRE class=html name="code" sizcache="0" sizset="69"><BLOCKQUOTE style="BORDER-BOTTOM-STYLE: none; PADDING-BOTTOM: 0px; BORDER-RIGHT-STYLE: none; MARGIN: 0px 0px 0px 40px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; BORDER-TOP-STYLE: none; BORDER-LEFT-STYLE: none; PADDING-TOP: 0px" sizcache="0" sizset="69"><PRE class=html name="code"></PRE><BR>
- <H3><A name=t14></A>6 參考</H3>
- http://wiki.apache.org/nutch/RunningNutchAndSolr
- <PRE></PRE>
- <SPAN style="FONT-FAMILY: Arial,Verdana,sans-serif"><SPAN style="WHITE-SPACE: normal"></SPAN></SPAN>
- <PRE></PRE>
- <BLOCKQUOTE></BLOCKQUOTE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <BLOCKQUOTE></BLOCKQUOTE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- </BLOCKQUOTE></PRE></PRE>
- <response>
- <lst name="responseHeader">
- <int name="status">0</int>
- <int name="QTime">0</int>
- <lst name="params">
- <str name="indent">on</str>
- <str name="start">0</str>
- <str name="q">baidu</str>
- <str name="version">2.2</str>
- <str name="rows">10</str>
- </lst>
- </lst>
- <result name="response" numFound="1" start="0">
- <doc>
- <float name="boost">1.0660036</float>
- <str name="digest">7be5cfd6da4a058001300b21d7d96b0f</str>
- <str name="id">http://www.baidu.com/</str>
- <str name="segment">20110822105243</str>
- <str name="title">百度一下,你就知道</str>
- <date name="tstamp">2011-08-22T14:56:09.194Z</date>
- <str name="url">http://www.baidu.com/</str>
- </doc>
- </result>
- </response>
<response>
<lst name="responseHeader">
<int name="status">0</int>
<int name="QTime">0</int>
<lst name="params">
<str name="indent">on</str>
<str name="start">0</str>
<str name="q">baidu</str>
<str name="version">2.2</str>
<str name="rows">10</str>
</lst>
</lst>
<result name="response" numFound="1" start="0">
<doc>
<float name="boost">1.0660036</float>
<str name="digest">7be5cfd6da4a058001300b21d7d96b0f</str>
<str name="id">http://www.baidu.com/</str>
<str name="segment">20110822105243</str>
<str name="title">百度一下,你就知道</str>
<date name="tstamp">2011-08-22T14:56:09.194Z</date>
<str name="url">http://www.baidu.com/</str>
</doc>
</result>
</response>
- <PRE class=html name="code" sizcache="0" sizset="69"><BLOCKQUOTE style="BORDER-BOTTOM-STYLE: none; PADDING-BOTTOM: 0px; BORDER-RIGHT-STYLE: none; MARGIN: 0px 0px 0px 40px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; BORDER-TOP-STYLE: none; BORDER-LEFT-STYLE: none; PADDING-TOP: 0px" sizcache="0" sizset="69"><PRE class=html name="code"></PRE><BR>
- <H3><A name=t14></A>6 參考</H3>
- http://wiki.apache.org/nutch/RunningNutchAndSolr
- <PRE></PRE>
- <SPAN style="FONT-FAMILY: Arial,Verdana,sans-serif"><SPAN style="WHITE-SPACE: normal"></SPAN></SPAN>
- <PRE></PRE>
- <BLOCKQUOTE></BLOCKQUOTE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <BLOCKQUOTE></BLOCKQUOTE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- </BLOCKQUOTE></PRE>
- <BLOCKQUOTE style="BORDER-BOTTOM-STYLE: none; PADDING-BOTTOM: 0px; BORDER-RIGHT-STYLE: none; MARGIN: 0px 0px 0px 40px; PADDING-LEFT: 0px; PADDING-RIGHT: 0px; BORDER-TOP-STYLE: none; BORDER-LEFT-STYLE: none; PADDING-TOP: 0px" sizcache="0" sizset="69"><PRE class=html name="code"></PRE><BR>
- <H3><A name=t14></A>6 參考</H3>
- http://wiki.apache.org/nutch/RunningNutchAndSolr
- <PRE></PRE>
- <SPAN style="FONT-FAMILY: Arial,Verdana,sans-serif"><SPAN style="WHITE-SPACE: normal"></SPAN></SPAN>
- <PRE></PRE>
- <BLOCKQUOTE></BLOCKQUOTE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- <BLOCKQUOTE></BLOCKQUOTE>
- <PRE></PRE>
- <PRE></PRE>
- <PRE></PRE>
- </BLOCKQUOTE>
6 參考
http://wiki.apache.org/nutch/RunningNutchAndSolr