Where exactly should hadoop.tmp.dir be set? core-site.xml or hdfs-site.xml?

Question

I'm asking about the Hadoop 2.x series. There's conflicting advice about this on the Internet. Like in this case where he asks to specify it in core-site.xml and this SO answer where it is mentioned that hadoop.tmp.dir be set in hdfs-site.xml. Which is the right place to put it?

Answer 1

hadoop.tmp.dir (A base for other temporary directories) is property, that need to be set in core-site.xml, it is like export in linux

Ex:

<name>dfs.namenode.name.dir</name>
<value>file://${hadoop.tmp.dir}/dfs/name</value>

You can use reference of hadoop.tmp.dir in hdfs-site.xml like above

For more core-site.xml and hdfs-site.xml

There're three HDFS properties which contain hadoop.tmp.dir in their values

dfs.name.dir: directory where namenode stores its metadata, with default value ${hadoop.tmp.dir}/dfs/name.

dfs.data.dir: directory where HDFS data blocks are stored, with default value ${hadoop.tmp.dir}/dfs/data.

fs.checkpoint.dir: directory where secondary namenode store its checkpoints, default value is ${hadoop.tmp.dir}/dfs/namesecondary