Lookup performance on ActionMappings

[Jonathan Asbell]

Our company manages almost 100 related sites, some with 3 million+ /month viewership.  In thinking about how I would approach the ActionServlet I am suspicious that the lookup time of the ActionMapping might become unsatisfactory when you reach a certain number of mappings.  Does anyone have any statistics?  Would you all suggest a servlet for each site in this case?  Keep in mind that all fo the sites share the common core enterprise framework.