The purpose of CA Common Services (CCS) Tomcat is to have one Tomcat installation that can be used by multiple products so you don't have to install a separate Tomcat installation for each product.
The next logical step is to have a single Tomcat instance host those multiple products. Unfortunately at this time products require their own Tomcat instance. To get to the next step we need to test the configuration and running of multiple products in a single Tomcat instance. Some products may do special processing in Tomcat that make them incompatible with other products.
When you install CCS Tomcat with SMP/E you get the Tomcat libraries for a specific Apache Tomcat release, e.g. the latest Apache Tomcat release that we packaged as CCS Tomcat for CCS 14.1 is 8.5.35. Before CCS Tomcat if you had 5 products that used Tomcat then you would have to install Tomcat 5 separate times. By installing CCS Tomcat you only have the one installation so when you need to upgrade Tomcat you only need to do one upgrade.
But those are only the libraries and other files that can be shared.
A CCS Tomcat instance is what is actually running, in a separate address space or started task. Before you can run CCS Tomcat with a product web application you need to deploy the Tomcat libraries so you aren't running out of the SMP/E target libraries. Then for each separate instance you need to create a new file system to hold logs and other content that is unique to that instance. This is also when you deploy the web application so it's unique to that Tomcat instance. Below is a picture.
In the JCL configure CATALINA_HOME to point to the deployed libraries which have been copied from the SMP/E target library. CATALINA_BASE in turn points to the file system that is unique to this Tomcat instance.
To get the best technical direction on actually setting this up please open a case under COMMON SERVICES where our technical support staff can help walk you through the setup.