Time for action – browsing default properties
Fortunately, the XML documents are not the only way of looking at the default values; there are also more readable HTML versions, which we'll now take a quick look at.
These files are not included in the Hadoop binary-only distribution; if you are using that, you can also find these files on the Hadoop website.
Point your browser at the
docs/core-default.html
file within your Hadoop distribution directory and browse its contents. It should look like the next screenshot:Now, similarly, browse these other files:
Hadoop/docs/hdfs-default.html
Hadoop/docs/mapred-default.html
What just happened?
As you can see, each property has a name, default value, and a brief description. You will also see there are indeed a very large number of properties. Do not expect to understand all of these now, but do spend a little time browsing to get a flavor for the type of customization allowed by Hadoop.
Additional property elements
When we have previously set properties...