To improve the performance of the Apache Tomcat Server you could use the Apache Tomcat Native library.
To install the library just execute:

# sudo aptitude install libtcnative-1

and add the following line to the file $CATALINA_HOME/bin/setenv.sh (create the file if it does not exist):

export LD_LIBRARY_PATH=/usr/lib:$LD_LIBRARY_PATH

To verify the library is running you will find the following message in $CATALINA_HOME/logs/catalina.out:

INFO: Loaded APR based Apache Tomcat Native library 1.1.19.

Without the Apache Tomcat Native library you will find a message like:

INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [...]