We are planning to migrate from Websphere Application Server 7 to Tomcat 7.x. Hence I need to pros and cons with the migration if anybody has already done this before. Also sharing any documentation will really be helpful for me. We will deploy all our ears which are currently in WAS7 to tomcat7, verisign certificate installation, datasource configuration, jndi configuration, etc, all these are involved as part of our migration.
It can be a lot harder to migrate from WAS to Tomcat than to go in the opposite direction. For example, you mentioned "deploying all your ears". That won't work, because Tomcat does not implement the entire J2EE stack, and one of the unsupported features is the EAR format. Tomcat can only handle WARs. Likewise, Tomcat does not contain its own EJB, JMS or mail facilities.
On the plus side, Tomcat is generally faster to start up and can be expected to use less resources, since it doesn't have to load and initialize all the features of the full stack.
Sometimes the only way things ever got fixed is because people became uncomfortable.
And depending on what you had WAS doing for you, you might also want to front Tomcat with Apache. And I thought there was some thing called EAS (enterprise application server), but I can't find that now.
Please ignore post, I have no idea what I am talking about.