I came across this issue in my lab the other day. I noticed that in Hyper-V Manager both of my Office Web Apps Servers had really high CPU utilization:
It's pretty rare that one of my VMs would be doing that much to consume that much of the CPU, so I looked at Task Manager on both of the VMs and saw that they were both pegging the processor:
Neither server should be this busy, so I checked out the Application Event Log to find out what was going on and found the following errors:
Log Name: Application
Source: .NET Runtime
Date: 3/29/2013 6:11:08 PM
Event ID: 1026
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: LAB-OWA1.lab.deitterick.com
Description:
Application: WordViewerWfeWatchdog.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.TypeInitializationException
Stack:
at Microsoft.Office.Web.Common.ServiceInstanceFinder.GetLocalAgentInstance(Microsoft.Office.Web.Common.OfficeServiceType)
at Microsoft.Office.Web.Common.WatchdogHelper.PrepareRegistrations(Microsoft.Office.Web.Common.OfficeServiceType)
at Microsoft.Office.Web.Common.WatchdogHelper.WatchMachines(Microsoft.Office.Web.Common.OfficeServiceType, CheckServiceInstance, Microsoft.Office.Web.Common.OfficeServiceType, System.String)
at Microsoft.Office.Web.WordViewerWatchdog.Wfe.Program.Main()
Log Name: Application
Source: Application Error
Date: 3/29/2013 6:11:08 PM
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
User: N/A
Computer: LAB-OWA1.lab.deitterick.com
Description:
Faulting application name: WordViewerWfeWatchdog.exe, version: 15.0.4481.1000, time stamp: 0x50ee5a74
Faulting module name: KERNELBASE.dll, version: 6.2.9200.16451, time stamp: 0x50988aa6
Exception code: 0xe0434352
Fault offset: 0x000000000003811c
Faulting process id: 0x17e8
Faulting application start time: 0x01ce2cca4f9a878f
Faulting application path: C:\Program Files\Microsoft Office Web Apps\WordViewerWfeWatchdog\WordViewerWfeWatchdog.exe
Faulting module path: C:\Windows\system32\KERNELBASE.dll
Report Id: 8e4fbe96-98bd-11e2-93f0-00155d010f10
Faulting package full name:
Faulting package-relative application ID:
There were tons of these errors in the Application Event Log. I found out that the issue occurred because I had automatic updates turned on in Microsoft Update:
Recently an update for Office Web Apps Server 2013 was installed:
Note: You may need to click on the image above in order to read the text.
Unfortunately Office Web Apps Server 2013 has specific steps that need to be followed in order to correctly apply updates. Those steps are detailed in the Apply software updates to Office Web Apps Server TechNet article. Since I let Microsoft Update automatically install the updates, the machines weren't removed from the Office Web Apps Server farm before the update was applied, which is what caused the errors listed above. Also unfortunate is that KB2760445 doesn't have an uninstall option. This means that to fix this issue you will need to uninstall Office Web Apps Server 2013, reinstall, and setup the Office Web Apps Server farm again:
Once Office Web Apps Server 2013 is installed again, and before you recreate the Office Web Apps Server farm, download and install KB2760445.
Note: You may need to restart the server in order for the Office Web Apps Server 2013 PowerShell cmdlets to be loaded back into PowerShell by default.
After installing KB2760445 and recreating the Office Web Apps Server farm, CPU utilization on the servers is back to normal:
In the future, to correctly install updates for Office Web Apps Server 2013, follow the steps listed in the Apply software updates to Office Web Apps Server TechNet article.