hadoop - NUTCH:如何使 take.screenshot 和 screenshot.location 属性起作用？

Question

一周以来我一直在学习 Nutch(版本 Nutch-1.14)，并且在本地模式以及 Hadoop-2.7.2(伪分布式模式)下工作正常。今天我在 nutch-site.xml 中遇到了“take.screenshot”、“screenshot.location”属性，修改这些属性后，nutch 正在抓取种子 url，但在本地模式和 Hadoop 中没有截图。

本地模式的 nutch-site.xml 设置

<property>
 <name>take.screenshot</name>
 <value>true</value>
 <description>
  Boolean property determining whether the protocol-htmlunit
  WebDriver should capture a screenshot of the URL. If set to
  true remember to define the 'screenshot.location'
  property as this determines the location screenshots should be
  persisted to on HDFS. If that property is not set, screenshots
  are simply discarded.
 </description>
</property>

<property>
 <name>screenshot.location</name>
 <value>/home/user/nutch-1.14/screenshot</value>
 <description>
  The location on disk where a URL screenshot should be saved
  to if the 'take.screenshot' property is set to true.
  By default this is null, in this case screenshots held in memory
  are simply discarded.
 </description>
</property>

Hadoop 的 nutch-site.xml 设置

<property>
 <name>take.screenshot</name>
 <value>true</value>
</property>

<property>
 <name>screenshot.location</name>
 <value>/screenshot</value>
</property>

备注 HDFS 中存在“screenshot”目录

Answer 1

您是否启用了 protocol-selenium ?基本上，这只适用于这个协议(protocol)，默认情况下 Nutch 使用 protocol-http不支持此选项的插件，即使您在配置中启用了这些设置。