Re: [xwiki-users] X11 needed on the server?

On Wed, Mar 11, 2009 at 7:03 AM, Paul Libbrecht <paul(a)activemath.org> wrote: You'll note in http://platform.xwiki.org/xwiki/bin/view/AdminGuide/Performances#Memory (and also my response in http://platform.xwiki.org/xwiki/bin/view/AdminGuide/Performances#comments ) the need for an additional flag for the JVM on Un*x/Linux systems -Djava.awt.headless=true (e.g. /usr/java/default/bin/java -server -Xms160m -Xmx1024m -XX:PermSize=160m -XX:MaxPermSize=320m -Djava.awt.headless=true -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=...) Add this flag, and some of the Java imaging routines stop needlessly requesting an X server. But on second though, this may not be so "needless" ... This very well could be the source of numerous scaling bugs with images and in the document converter and PDF/RTF export. The whole reason why imaging routines would be asking for the X server in the first place is to get the DPI of the display. On linux systems, that information is either defaulted, or explicitly and correctly set based on the actual display and monitor size you are using. I believe the -Djava.awt.headless=true setting allows these imaging routines to "work" but with a wrong-default DPI for the "display" they expect to display to. To solve, additional env-variables or properties need to be passed-in with a correct default DPI, such as 100x100. Or even better, do-it-right and figure out a way to get the web-browser to report the actual DPI of the user's system that will ultimately be displaying the image. For more info on potentially related scaling issues, see: http://jira.xwiki.org/jira/browse/XWIKI-2556 http://jira.xwiki.org/jira/browse/XWIKI-3216?focusedCommentId=37483&pag… http://jira.xwiki.org/jira/browse/XWIKI-3216?focusedCommentId=37513&pag… http://jira.xwiki.org/jira/browse/XWIKI-3216?focusedCommentId=37538&pag… Niels http://nielsmayer.com