Frequently Asked Questions

Q: Why won't the charts render when the server is run on Linux/Unix?

A:  Java requires a GUI to perform any AWT functions. A Linux machine that isn't running X Windows doesn't have a GUI for Java to use. You need to run AWT headless or otherwise provide an X session for AWT to use as a virtual drawing environment.

• JDK 1.4 and above, all you need to do is start your JVM with the -Djava.awt.headless=true parameter.
• JDK 1.3 and 1.2, use Xvfb (X Virtual Frame Buffer) that comes with XFree86 distribution.  It provides the necessary hooks for Java to use the AWT. Xvfb is an X server that can run on machines with no display hardware and no physical input devices. It emulates a dumb framebuffer using virtual memory. To set up Xvfb, do the following:
  
  

  			nohup /usr/bin/X11/Xvfb :1 &
  			export DISPLAY=localhost:1