In tomcat, what is catalina_home and why we use it?

Question

Iam new to tomcat but i knew something in java, While setting up tomcat we use to set java_home for the jdk path but all i wanted to knew what is catalina_home and why we need to setup in catalina.sh?

Answer 1

CATALINA_HOME is the folder where Apache Tomcat is installed e.g. c:\program files\Apache Tomcat or /usr/apache/tomcat. It is the folder where you unzip Tomcat in the first place (when you install from zip).

CATALINA_HOME is necessary because a lot of the files Tomcat will use are referred to from the variable CATALINA_HOME. For instance log files are written inside CATALINA_HOME/logs. Configuration is read from CATALINA_HOME/conf.

If you try to run Tomcat with the wrong CATALINA_HOME, things will go wrong.

Answer 2

Tomcat is actually composed of a number of components, including a Tomcat JSP engine and other connectors, but the main component is Catalina, which provides the implementation of the servlet specification. When starting the Tomcat server, it's Catalina that is actually starting. The variable 'catalina_home' is a configuration property that stores the location of the Catalina files.

These are the configuration files in Tomcat's "$CATALINA_BASE/conf" directory:

• catalina.policy
• catalina.properties
• logging.properties
• content.xml
• server.xml
• tomcat-users.xml
• web.xml