Below are some small notes I've jotted down when working with Tomcat.
We have experience performance problems becaues of this method:
org.apache.catalina.core.ApplicationContext.findAttribute(String) which is synchronised. Thus, limit your
application's usage of this method.
Cannot find javax/servlet/Filter
I all of a sudden started getting this exception on my Tomcat 6.0.10:
SEVERE: Exception starting filter authenticationFilter java.lang.NoClassDefFoundError: javax/servlet/Filter
$CATALINA_HOME/lib/servlet-api.jar seemed to
miraculously fix the problem.