Remove the cache. Generally, it makes performance worse not better. Testing with the jars that ship with Jira, performance was improved by around 10-15% by removing the cache.
Based on a suggestion by hzhang9

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1624476 13f79535-47bb-0310-9956-ffa450edef68