Apache Tomcat 8.0.20 发布，该版本值得关注的 bug 修复包括：

- Fix a performance regression in the new resources implementation
  when signed JARs are used in a web application.

- Fix several bugs that could cause multiple registrations for write
  events for a single socket when using Servlet 3.0 async. Typically,
  the side effects of these multiple registrations would be
  exceptions appearing in the logs.

- Enhance the bean factory used for JNDI resources. The new
  attribute forceString allows to support non-standard string
  argument property setters.

完整记录请看 http://tomcat.apache.org/tomcat-8.0-doc/changelog.html