JBoss and debug breakpoints

The problem

Got in on a Monday morning ready to write some code.  Start up the JBoss server via JBoss tools, but it just freezes after a while.  Works perfectly with debug arguments.  So I started the server via the bin/debug.sh command and connected Eclipse to the JBoss server.  As soon as I connected to the server it froze and when I disconnected everything went back to normal...

The Solution

Debug breakpoint in a EJB causes a heavy overhead to JBoss startup.  And that is exactly what I did had a breakpoint left in from the previous week.  So remove all breakpoints when you have finished debugging!

Packet drops in Ubuntu and Fedora with Realtek NIC driver r8169

The Problem
I recently purchased a Gigabyte GA-Z68X-UD4-B3 motherboard, installed Ubuntu and started to download eclipse.  The download took forever!  Tried to open a few websites and some of them just timed out.  I was just about to get on the phone with the ISP when I noticed doing a ping the router some packets where being lost!


The solution
The motherboard comes with a Realtek network card running the r8169 chip.  Now for some reason Ubuntu and Fedora detects this as a r8168.

To check this run:

lsmod | grep r8168

If you get a output if means your using the r8168 driver instead of the r8169.

Step one is to download the driver required from Realtek
http://www.realtek.com.tw/downloads/downloadsView.aspx?Langid=1&PNid=13&PFid=5&Level=5&Conn=4&DownTypeID=3&GetDown=false

Once the download is complete extract

tar vjxf r8168-8.tar.bz2

The next step will disable the network interface, remove the r8168 module.

sudo rmmod r8168

Now run the autorun.sh file in the extracted folder

sudo ./autorun.sh

Blacklist the r8168 module form being loaded again you will have to add it to the blacklist

sudo gedit /etc/modprobe.d/blacklist.conf

Add the following line:

blacklist r8169

Update the driver cache

sudo update-initramfs -u

Now to check that everything went according to plan run

lsmod | grep r8168

If you get a output your done and dusted!

LXDE HDMI as default audio output device

The Problem:

If you are have a old pc running a lightweight linux interface like LXDE or XFCE, e.g LUbuntu and need to get the audio out to work via the HDMI you most probably have notices there is not a nice GUI to do this like in Ubuntu.

The Solution:

pavucontrol is a great and simple solution.  I know it is a bit heavyweight since you have to install pulseaudio but it is the easiest solution I have found.  To install:

sudo apt-get install pulseaudio pavucontrol

then to run

pavucontrol

Cannot create Seam component, scope is not active

The problem:

I kept on running into to following error:
WARN  [org.jboss.seam.Component]  Cannot create Seam component, scope is not active: mySuperAction(CONVERSATION)
SEVERE [javax.enterprise.resource.webcontainer.jsf.lifecycle] JSF1054: (Phase ID: RESTORE_VIEW 1, View ID: /ThePage.xhtml) Exception thrown during phase execution: javax.faces.event.PhaseEvent[source=com.sun.faces.lifecycle.LifecycleImpl@19da36b]

Seam said my long-running conversation was gone.  But how could this be!  Well after a lot of digging I found this hidden line in the Seam documentation:

Conversational components have one minor limitation: they cannot be used to hold bindings to JSF components. 

What I was doing is I had a DataTable binding in the JSF.  The reason for this is I was not sure what columns or data was going to be displayed for the datatable until the time the page was being generated.

The solution:

As stated in the documentation, move and the HtmlPanelGrid in a new container with scope set to EVENT.

@Name("grid")
@Scope(ScopeType.EVENT)
public class Grid
{
    private HtmlPanelGrid htmlPanelGrid;

    // getters and setters
    ...
}@Name("mySuperAction")
@Scope(ScopeType.CONVERSATION)
public class MySuperAction
{
    @In(create=true)
    private Grid grid;
   
    private void populateTable(){....}

 }


Add to the page.xml a new action that calls the populateTable:

<action execute="#{mySuperAction.populateTable}" />


Now for the binding:

<h:panelGroup id="dynamicTablePanel" binding="#{grid.htmlPanelGrid}" />


Just as a note I found in a few forum posts where made where they stated adding getters and setters for the Grid on the MySuperAction thus making the binding look like this:

 <h:panelGroup id="dynamicTablePanel" binding="#{mySuperAction.grid.htmlPanelGrid}" />

This will work until you do your first AJAX call on the page and you will be hit with a nice RESTORE_VIEW error.