For all the examples i've seen on Tomcat lb workers, I have yet to discover where this mysterious 'worker' is located. Is it IN my Apache instance? Is it THE apache instance? Is it a SEPARATE tomcat instance other than my instances which are processing the requests?
The workers are separate Tomcat instances. Apache (using mod_jk) knows how to distribute requests to multiple instances of Tomcat to serve. You can have multiple workers on one machine, or workers distributed across multiple machines. It's up to you to start and setup the workers, and then you describe them to mod_jk in the worker.properties files.
I'm going to move this to our Apache/Tomcat forum, where any further discussion will be on-topic.
"A Tomcat worker is a Tomcat instance that is waiting to execute servlets on behalf of some web server."
A load balancing worker:
"knows how to provide round-robin based sticky load balancing with a certain level of fault-tolerance"
Thereofore if i am trying to load balance across 4 tomcat instances that are forwarded requests from an Apache Web server do i actually need 5 Tomcat instances (one to act as the load balancing worker)??? Or is my Apache web server the "load balancing worker"?