我正在尝试进行 hadoop 单节点安装。

我正在关注 this有关 hadoop 安装说明的文章。我需要做的步骤之一是使用命令格式化 hadoop 文件系统

hduser@dbserver:~/hadoop/conf$/home/hduser/hadoop/bin/hadoop namenode -format

hduser@dbserver:~/hadoop/conf$ /home/hduser/hadoop/bin/hadoop namenode -format
12/02/06 18:24:31 INFO namenode.NameNode: STARTUP_MSG: 
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = dbserver/127.0.1.1
STARTUP_MSG:   args = [-format]
STARTUP_MSG:   version = 0.20.203.0
STARTUP_MSG:   build = http://svn.apache.org/repos/asf/hadoop/common/branches/branch-    0.20-security-203 -r 1099333; compiled by 'oom' on Wed May  4 07:57:50 PDT 2011
 ************************************************************/
 [Fatal Error] core-site.xml:6:1: Content is not allowed in prolog.
 12/02/06 18:24:31 FATAL conf.Configuration: error parsing conf file:  org.xml.sax.SAXParseException: Content is not allowed in prolog.
 12/02/06 18:24:31 ERROR namenode.NameNode: java.lang.RuntimeException: org.xml.sax.SAXParseException: Content is not allowed in prolog.
at org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:1237)
at org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:1093)
at org.apache.hadoop.conf.Configuration.getProps(Configuration.java:1037)
at org.apache.hadoop.conf.Configuration.set(Configuration.java:438)
at org.apache.hadoop.hdfs.server.namenode.NameNode.setStartupOption(NameNode.java:1124)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1141)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1162)
 Caused by: org.xml.sax.SAXParseException: Content is not allowed in prolog.
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:249)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:284)
at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:180)
at org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:1142)
... 6 more

    12/02/06 18:24:31 INFO namenode.NameNode: SHUTDOWN_MSG: 
    /************************************************************
      SHUTDOWN_MSG: Shutting down NameNode at dbserver/127.0.1.1
    ************************************************************/

我在尝试格式化时收到上述错误消息

欢迎提出解决此问题的任何建议 :)。

core-site.xml 文件在这里供您引用@zensen

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

 <!-- Put site-specific property overrides in this file. -->

  n: conf/core-site.xml -->
  <property>
  <name>hadoop.tmp.dir</name>
  <value>/app/hadoop/tmp</value>
  <description>A base for other temporary directories.</description>
  </property>

    <property>
    <name>fs.default.name</name>
    <value>hdfs://localhost:54310</value>
    <description>The name of the default file system.  A URI whose
    scheme and authority determine the FileSystem implementation.  The
    uri's scheme determines the config property (fs.SCHEME.impl) naming
     the FileSystem implementation class.  The uri's authority is used to
    determine the host, port, etc. for a filesystem.</description>
   </property><configuration>

~

最佳答案

嗯，这不是真正的 Hadoop 问题。

org.xml.sax.SAXParseException: Content is not allowed in prolog.

表示您的 XML 文件不正确。更准确地说，它在 <?xml 之前包含一些字符。 . core-site.xml里面有没有字符在一开始之前 <?xml ？如果是这样，则将其删除。请记住，这些可能不会在所有编辑器中显示(取决于编码)。

关于xml - Hadoop单节点安装-格式化错误-Content is not allowed in prolog，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/9168958/