【Nutch2.2.1基础教程之2.1】集成Nutch/Hbase/Solr构建搜索引擎之一：安装及运行【单机环境】

1、下载相关软件，并解压

版本号如下：

（1）apache-nutch-2.2.1

（2） hbase-0.90.4 

（3）solr-4.9.0

并解压至/usr/search

2、Nutch的配置

（1）vi /usr/search/apache-nutch-2.2.1/conf/nutch-site.xml 

<property>
<name>storage.data.store.class</name>
<value>org.apache.gora.hbase.store.HBaseStore</value>
<description>Default class for storing data</description>
</property>

（2）vi /usr/search/apache-nutch-2.2.1/ivy/ivy.xml 

默认情况下，此语句被注释掉，将其注释符号去掉，使其生效。

    <dependency org="org.apache.gora" name="gora-hbase" rev="0.3" conf="*->default" />

（3）vi /usr/search/apache-nutch-2.2.1/conf/gora.properties 

添加以下语句：

gora.datastore.default=org.apache.gora.hbase.store.HBaseStore

以上三个步骤指定了使用HBase来进行存储。

以下步骤才是构建基本Nutch的必要步骤。

（4）构建runtime

 cd /usr/search/apache-nutch-2.2.1/

ant runtime

（5）验证Nutch安装完成

[root@jediael44 apache-nutch-2.2.1]# cd /usr/search/apache-nutch-2.2.1/runtime/local/bin/
[root@jediael44 bin]# ./nutch 
Usage: nutch COMMAND
where COMMAND is one of:
 inject         inject new urls into the database
 hostinject     creates or updates an existing host table from a text file
 generate       generate new batches to fetch from crawl db
 fetch          fetch URLs marked during generate
 parse          parse URLs marked during fetch
 updatedb       update web table after parsing
 updatehostdb   update host table after parsing
 readdb         read/dump records from page database
 readhostdb     display entries from the hostDB
 elasticindex   run the elasticsearch indexer
 solrindex      run the solr indexer on parsed batches
 solrdedup      remove duplicates from solr
 parsechecker   check the parser for a given url
 indexchecker   check the indexing filters for a given url
 plugin         load a plugin and run one of its classes main()
 nutchserver    run a (local) Nutch server on a user defined port
 junit          runs the given JUnit test
 or
 CLASSNAME      run the class named CLASSNAME
Most commands print help when invoked w/o parameters.

（6）vi /usr/search/apache-nutch-2.2.1/runtime/local/conf/nutch-site.xml 添加搜索任务

<property>
<name>http.agent.name</name>
<value>My Nutch Spider</value>
</property>

（7）创建seed.txt

 cd /usr/search/apache-nutch-2.2.1/runtime/local/bin/

vi seed.txt

http://nutch.apache.org/

（8）修改网页过滤器  vi /usr/search/apache-nutch-2.2.1/conf/regex-urlfilter.txt 

 vi /usr/search/apache-nutch-2.2.1/conf/regex-urlfilter.txt 

将

# accept anything else
+.

修改为

# accept anything else
+^http://([a-z0-9]*.)*nutch.apache.org/

(9)增加索引内容

默认情况下，schema.xml文件中的core及index-basic中的field才会被索引，为索引更多的field，可以通过以下方式添加。

修改nutch-default.xml，新增以下红色内容

<property>

  <name>plugin.includes</name>

 <value>protocol-http|urlfilter-regex|parse-(html|tika)|index-(basic|anchor)|urlnormalizer-(pass|regex|basic)|scoring-opic|index-anchor|index-more|languageidentifier|subcollection|feed|creativecommons|tld</value> 

 <description>Regular expression naming plugin directory names to

  include. Any plugin not matching this expression is excluded.

  In any case you need at least include the nutch-extensionpoints plugin. By

  default Nutch includes crawling just HTML and plain text via HTTP,

  and basic indexing and search plugins. In order to use HTTPS please enable

  protocol-httpclient, but be aware of possible intermittent problems with the

  underlying commons-httpclient library.

  </description>

</property>

或者可以在nutch-site.xml中添加plugin.includes属性，并将上述内容复制过去。注意，在nutch-site.xml中的属性会代替nutch-default.xml中的属性，因此必须将原有的属性也复制过去。

3、Hbase的配置

（1）vi /usr/search/hbase-0.90.4/conf/hbase-site.xml 

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<configuration>
<property>
<name>hbase.rootdir</name>
<value><Your path></value>
</property>
<property>
<name>hbase.zookeeper.property.dataDir</name>
<value><Your path></value>
</property>
</configuration>

注：此步骤可不做。若不做，则使用hbase-default.xml（/usr/search/hbase-0.90.4/src/main/resources/hbase-default.xml）中的默认值。

默认值为：

  <property>
    <name>hbase.rootdir</name>
    <value>file:///tmp/hbase-${user.name}/hbase</value>
    <description>The directory shared by region servers and into
    which HBase persists.  The URL should be 'fully-qualified'
    to include the filesystem scheme.  For example, to specify the
    HDFS directory '/hbase' where the HDFS instance's namenode is
    running at namenode.example.org on port 9000, set this value to:
    hdfs://namenode.example.org:9000/hbase.  By default HBase writes
    into /tmp.  Change this configuration else all data will be lost
    on machine restart.
    </description>
  </property>

即默认情况下会放在/tmp目录，若机器重启，有可能数据丢失。

但是建议还是把这些属性做好配置，尤其是第二个关于zoopkeeper的，否则会导致各种问题。以下将目录配置在本地文件系统中。

<configuration>
<property>
<name>hbase.rootdir</name>
<value>file:///home/jediael/hbaserootdir</value>
</property>
<property>
<name>hbase.zookeeper.property.dataDir</name>
<value>file:///home/jediael/hbasezookeeperdataDir</value>
</property>

</configuration>

注意，若无前缀file://，则默认是hdfs://

但在0.90.4版本，默认还是本地文件系统。

4、Solr的配置

（1）覆盖solr的schema.xml文件。（对于solr4，应该使用schema-solr4.xml)

cp /usr/search/apache-nutch-2.2.1/conf/schema.xml /usr/search/solr-4.9.0/example/solr/collection1/conf/

（2）若使用solr3.6，则至此已经完成配置，但使用4.9，需要修改以下配置：

修改上述复制过来的schema.xml文件

删除：<filter class="solr.EnglishPorterFilterFactory" protected="protwords.txt" /> 

增加：<field name="_version_" type="long" indexed="true" stored="true"/>

5、启动抓取任务

（1）启动HBase

[root@jediael44 bin]# cd /usr/search/hbase-0.90.4/bin/
[root@jediael44 bin]# ./start-hbase.sh 

（2）启动Solr

[root@jediael44 bin]# cd /usr/search/solr-4.9.0/example/
[root@jediael44 example]# java -jar start.jar 

（3）启动Nutch，开始抓取任务

[root@jediael44 example]# cd /usr/search/apache-nutch-2.2.1/runtime/local/bin/
[root@jediael44 bin]# ./crawl seed.txt TestCrawl http://localhost:8983/solr 2

大功告成，任务开始执行。

关于上述过程的一些分析请见：

集成Nutch/Hbase/Solr构建搜索引擎之二：内容分析

http://blog.csdn.net/jediael_lu/article/details/37738569

使用crontab来设置Nutch的例行任务时，出现以下错误

JAVA_HOME is not set。

于是创建了一个脚本，用于执行抓取工作：

#!/bin/bash
export JAVA_HOME=/usr/java/jdk1.7.0_51
/opt/jediael/apache-nutch-2.2.1/runtime/local/bin/crawl /opt/jediael/apache-nutch-2.2.1/runtime/local/urls/ mainhttp://localhost:8080/solr/ 2 >> ~jediael/nutch.log

然后再配置例行任务

30 0,6,8,10,12,14,16,18,20,22 * * * bash /opt/jediael/apache-nutch-2.2.1/runtime/local/bin/myCrawl.sh