java.io.tmpdir has no effect on changing the installation temp directory

Issue Summary

java.io.tmpdir has no effect on changing the installation temp directory

In the this documentation about changing the installation temp directory. It is advised to use the Java parameter below:

-Djava.io.tmpdir=/path/to/your/own/temp/directory

In the catalina.sh and catalina.bat file, the comment below suggests the same as well:

#   CATALINA_TMPDIR (Optional) Directory path location of temporary directory
#                   the JVM should use (java.io.tmpdir).  Defaults to
#                   $CATALINA_BASE/temp.

rem   CATALINA_TMPDIR (Optional) Directory path location of temporary directory
rem                   the JVM should use (java.io.tmpdir).  Defaults to
rem                   %CATALINA_BASE%\temp.

However, having this Java parameter set has no effect on changing the installation temp directory

Tested Environment

Confluence 6.15.1
Confluence 7.3.3

Steps to Reproduce

1. Stop a vanilla Confluence and add the system property below:

   -Djava.io.tmpdir=/somewhere/doesnt/matter 
   

2. Restart Confluence

Expected Results

The Installation Temp directory will be changed according to the Java parameter included

Actual Results

The Installation Temp directory is not changed despite the Java parameter can be seen to parsed successfully into Confluence:

Meanwhile, the original installation temp directory will still be used and a second set of java.io.tmpdir can be seen

Workaround

Add this line into setenv.sh according to the Jira KB:

CATALINA_TMPDIR='/path/to/new/installation/temp'

Note

The newly changed installation temp directory from the workaround step may not be created by Confluence if it doesn't already exist due to CONFSERVER-59610