Upgrading Tomcat from 4.1.x to 5.0.x

[Rhino]

I've been using Tomcat 4.124 and now Tomcat 4.1.29 with good results but I'm thinking it might be time to upgrade to Tomcat 5.0.x.   Are there any cautions/warnings/problems or just differences that I should expect between the two? For instance, will my servlets need to change in any way to run in 5.0.x? Will administration of the servlets change in any way? If there is anything I should do to prepare for the upgrade, particularly steps that minimize problems, I'd like to do so.   Am I right in believing that I should normally not remove old versions before installing newer versions of Tomcat; that new versions simply go on "in parallel", i.e. they are put in different directories than the old versions? That's what I did when going from 4.1.24 to 4.1.29 in Windows XP.   However, we also have Tomcat on our Linux Mandrake 9.1 server and the administrator wants to use urpm to simply overlay 4.1.24 on Linux with 5.0.x. Is that safe or should we do it some other way? Rhino --- rhino1 AT sympatico DOT ca "If you want the best seat in the house, you'll have to move the cat."