...

<Connector
    port="8080"
    maxHttpHeaderSize="8192" maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
    enableLookups="false" redirectPort="8443" acceptCount="100"
    connectionTimeout="20000" disableUploadTimeout="true"
    emptySessionPath="true" />

Statistics charts do not appear (InternalError)

At first check that the emptySessionPath parameter is correctly set as shown above.

...

unset DISPLAY

Statistics charts do not appear (NoClassDefFoundError)

If you get the following error:

java.lang.NoClassDefFoundError

It is probably an X11 issue (the AWT library tries to use an unexistant X11 server to generate images). Add the following option when launching the application:

java -Djava.awt.headless=true ...

See:

• http://www.jfree.org/jfreechart/faq.html#FAQ10
• http://java.sun.com/products/java-media/2D/reference/faqs/index.html#Q_I_have_an_application_that_rea 
• http://www.jfree.org/phpBB2/viewtopic.php?t=1012 

There are unused things in the database

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