Samanthi perera wrote:anyway what is the use of CATALINA_HOME ?
Why we set this variable?
CATALINA_HOME is used by Tomcat startup scripts and Tomcat itself. Tomcat converts it from an environment variable to a system property, which gets used in the Tomcat code. If you do not set CATALINA_HOME and start Tomcat using the startup scripts, it tries to set CATALINA_HOME.
Actually, there are two environment variables. CATALINA_HOME and CATALINA_BASE. For most of us, they'll both have the same value, and they'll point to the Tomcat directory. However, you can have multiple copies of Tomcat running on a machine. In this case, they may all have a common shared codebase, but they may be running different webapps, and they'll certainly be using different ports. So you set CATALINA_HOME to the tomcat directory, then create a separate directory for each Tomcat instance and launch it with a different CATALINA_BASE. The CATALINA_BASE directory contains a distinct copy of the conf, work, webapps, logs and temp directories.
I may have CATALINA_HOME and CATALINA_BASE backwards, so if you plan to use this feature, be sure to look it up in the Tomcat docs. After all these years, I can still never remember which is which. Like I said, it's a very useful feature, but not one that many of us commonly use.
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