In our experience, Tomcat 5/6 are very good in terms of performance. There is little or no performance improvement using Apache / mod_jk. Apache is however, essential if you cluster Alfresco and have multiple Tomcat instances. For a single instance it is not necessary.
When you cluster Alfresco / Tomcat you'll have a minimum of two separate servers. This means two separate IP addresses. Unless you are using DNS round robin you'd want your end users to access Alfresco at a specific URL. Point this at Apache HTTP and let it manage which of the Alfresco instances the request is forwarded to.
Hi therem for a dynamic application, I can second that experience. For inclusion in a bigger static site or CMS driven site, tomcat as appliation container and Appache as static server and ssl frontend helps a bit.
I have alfresco 3.4.d in our production environment. Everything is working fine except Where ajax is used in the alfresco. Like selecting destination while Exporting acp, Selecting userhome while creating new user. No stacktrace is found in any of the log file.
