nutch fetch 失败并出现 java.lang.NumberFormatException

Question

I am running Nutch 1.18 on Red Hat Enterprise Linux release 8.3 (Ootpa) w/ Java openjdk version "1.8.0_275"

I am following these directions: https://cwiki.apache.org/confluence/display/NUTCH/NutchTutorial#NutchTutorial-Step-by-Step:Concepts

When I get to the step for bin/nutch fetch $s1 every fetch is failing. See a sample error from the hadoop log below. They all fail with java.lang.NumberFormatException. I can use curl to check that the urls are accessible and they are.

Any advice would be appreciated.

    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:583)
    at java.lang.Integer.parseInt(Integer.java:615)
    at org.apache.hadoop.conf.Configuration.getInt(Configuration.java:1486)
    at org.apache.nutch.protocol.http.api.HttpBase.setConf(HttpBase.java:212)
    at org.apache.nutch.protocol.http.Http.setConf(Http.java:52)
    at org.apache.nutch.plugin.Extension.getExtensionInstance(Extension.java:169)
    at org.apache.nutch.protocol.ProtocolFactory.getProtocolInstanceByExtension(ProtocolFactory.java:177)
    at org.apache.nutch.protocol.ProtocolFactory.getProtocol(ProtocolFactory.java:155)
    at org.apache.nutch.fetcher.FetcherThread.run(FetcherThread.java:308)```

Answer 1

The stack (keywords: protocol, http, configuration, parseInt) already tells that some integer value of a configuration property failed to read. When looking into the source code (HttpBase.java, line 212) it becomes clear that it's about the configuration property "http.timeout":

<property>
  <name>http.timeout</name>
  <value>10000</value>
  <description>The default network timeout, in milliseconds.</description>
</property>

Please verify that it is configured correctly - an integer value and a reasonable time span.