XInclude and tags in conf files

[Derek Brown <de...@media6degrees.com>]

Regarding the ability to include other files in configuration files:
http://issues.apache.org/jira/browse/HADOOP-4944

I'm seeing apparent differing behavior that may make sense to someone. I say
I have my core-site.xml as follows:


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

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

<configuration xmlns:xi="http://www.w3.org/2001/XInclude">

  <!-- various normal <property> tags here... -->

  <xi:include href="include-site.xml"/>

</configuration>


include-site.xml has (only) multiple <property> elements in it, in the same
form as entries in core-site.xml (or hdfs-site or mapred-site).

Using the normal apache hadoop 0.20.1 installation (on an OS X box), that
works fine.

Using a current Cloudera 0.20.1 install (on CentOS) I'm seeing this fail
with the following error (when doing any command line operation, such as
"hadoop fs -ls"):


[Fatal Error] include-site.xml:6:2: The markup in the document following the
root element must be well-formed.
[Fatal Error] core-site.xml:8:40: Error attempting to parse XML file
(href='include-site.xml').
09/12/28 18:09:05 FATAL conf.Configuration: error parsing conf file:
org.xml.sax.SAXParseException: Error attempting to parse XML file
(href='include-site.xml').
Exception in thread "main" java.lang.RuntimeException:
org.xml.sax.SAXParseException: Error attempting to parse XML file
(href='include-site.xml').
    at
org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:1266)
    at
org.apache.hadoop.conf.Configuration.loadResources(Configuration.java:1125)
    at
org.apache.hadoop.conf.Configuration.getProps(Configuration.java:1064)
    at org.apache.hadoop.conf.Configuration.set(Configuration.java:447)
    at
org.apache.hadoop.conf.Configuration.setBoolean(Configuration.java:627)
    at
org.apache.hadoop.util.GenericOptionsParser.processGeneralOptions(GenericOptionsParser.java:290)
    at
org.apache.hadoop.util.GenericOptionsParser.parseGeneralOptions(GenericOptionsParser.java:375)
    at
org.apache.hadoop.util.GenericOptionsParser.<init>(GenericOptionsParser.java:153)
    at
org.apache.hadoop.util.GenericOptionsParser.<init>(GenericOptionsParser.java:138)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:59)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79)
    at org.apache.hadoop.fs.FsShell.main(FsShell.java:1880)
Caused by: org.xml.sax.SAXParseException: Error attempting to parse XML file
(href='include-site.xml').
    at
com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:239)
    at
com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:283)
    at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:180)
    at
org.apache.hadoop.conf.Configuration.loadResource(Configuration.java:1174)
    ... 11 more


Line 6 in include-site.xml (as referenced at the top of the error) is the
line with the second <property> element, and line 8 of core-site.xml in the
one with the include. If I put the property entries in multiple include
files, one each, and include each, it will work.

Thanks for any insight,
Derek