The best way to describe a Watchdog software is like a reserve parachute. As a paratrooper you sure hope your 1st  parachute will always open and you will land safely, but its sure nice to know you have that extra reserve parachute just in case.

Same thing with our Digital Signage software. At MediaSignage we go to great length making sure the SignagePlayer software is reliable, memory leak free and can operate for weeks or even months without a reboot. However, it’s nice to know the Watchdog software service is watching over your SignagePlayer just in case things don’t go right.

The Watchdog has the power to restart the SignagePlayer and put it back into normal operation.

Also, you should remember that the MediaSignage platform allows you to upload swf modules. Swfs are applications or animations developed using Adobe Flex, Adobe Flash or other editors. And if the swf program contains dirty code which leaks memory, or even illegal instructions, that swf may cause the SignagePlayer to crash.

In a perfect world, any swf which you download from the internet (whether its animation or a small program) should be safe and reliable. But since that is not the case, we depend on the Watchdog to make sure the SignagePlayer is stable and run uninterrupted, regardless of what executes inside of it.

One way to find out if your SignagePlayer is leaking memory is to monitor the memory totals and peak. Under the stations section of the SignageStudio you can monitor real time memory usage of each SignagePlayer. If the memory continues to increase without ever stabilizing, you may suspect a leaking swf. You can see from the screen shot below that the peak memory registers at 82.276M. If the value increases indefinitely, you can suspect a memory leak.

Also, remote reboot ( displayed as a green icon on the diagram below) is a functionality of the WatchDog.

To install the WatchDog, click on the “install watchdog” button. This should be done on every machine that runs the SignagePlayer. The Watchdog is a small application and it has no options that are configurable via the Watchdog GUI (graphical user interface).

All of the options for the Watchdog are configurable via the Stations section of the SignageStudio and can be set per SignagePlayer. These reboot conditions include exceed memory threshold parameter, scheduled time parameter and internal error parameter.

One thing you should do is disable the “Dr. Watson” debug service under Windows XP. This service will show a dialogue (such as the one to the right) anytime any application crashes.  Unfortunately this will prevent the Watchdog from ever being able to restart the SignagePlayer until you manually close this disallow.
To prevent this from ever appearing, simply disable the “Dr. Watson” service under Windows XP.

To disable Dr. Watson

1. Click Start, click Run, type regedit.exe in the Open box, and then click OK.

2. Locate and click the following registry key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\AeDebug
NOTE: Steps three and four are optional, but they necessary if you want to restore the default use of Dr. Watson.

3. Click the AeDebug key, and then click Export Registry File on the Registry menu.

4. Enter a name and location for the saved registry file, and then click Save.

5. Delete the AeDebug key.


Registry entries for debugger programs are located in the AeDebug key in Windows. The Dr. Watson program is installed by default in Windows, and is configured to run when an application error occurs (with a data value of 1 for the Auto value). The default values are:
Value Name = Auto
Type = String (REG_SZ)
Data Value = 1 or 0. (Default is 1)

Value Name = Debugger
Type = String (REG_SZ)
Data Value = drwtsn32 -p %ld -e %ld -g

NOTE: This data value (drwtsn32 -p %ld -e %ld -g) is specific to Dr. Watson. Alternative debuggers will have their own values and parameters.


To enable Dr. Watson
1. At a command prompt, type the following line, and then press ENTER:

drwtsn32 -i
2. Double-click the .reg file you created in steps three and four above.

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