What is an invoker servlet in a Tomcat servlet container?
If you look at the contents of the webapp deployment descriptor file, web.xml, in the TOMCAT_HOME/conf directory, you will find the following servlet element at the beginning:
<servlet> <servlet-name> invoker </servlet-name> <servlet-class> org.apache.tomcat.servlets.InvokerServlet </servlet-class> </servlet>which declares the name and the place of the system-supplied invoker servlet. Shortly thereafter appears the following servlet-mapping element:
<servlet-mapping> <servlet-name> invoker </servlet-name> <url-pattern> /servlet/* </url-pattern> </servlet-mapping>which tells the container that all requests that begin with "/servlet" (relative to root of the webapp specified by the name that comes before "/servlet") are to be sent to the invoker servlet.
The highly informative posting by Craig McClanahan is the source of the information supplied here.