Installing Oracle Client on Windows 7

During the install of Oracle Client on my brand new Windows 7 machine, I got the following error:

This seemed like a showstopper to me, but was actually just bad usability from Oracle (surprise!):

Checking the checkbox changes the status from “Error” to “User verified”, and allows me to continue installing…

Great!

What I really wanted was the 64-bit versjon, but that’s another story…

Troubleshooting errors in WCF Service

WCF hides all details of any errors on the server. This is done deliberately, as a security feature, but it makes it a bit harder to troubleshoot when something goes wrong.
Fortunately, Microsoft has provided some good tools for tracing in WCF, so it’s quite easy to see what’s really going on on the server.

What you typically see on the client is this:

   A first chance exception of type 'System.ServiceModel.CommunicationException' occurred in mscorlib.dll System.ServiceModel.CommunicationException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.
---> System.Net.WebException: The underlying connection was closed: A connection that was expected to be kept alive was closed by the server.
--->; System.IO.IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.
--->; System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
  at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 size)

On Server you must make the following change to the WCF service application config file (web.config if the server is hosted in IIS)

<system.diagnostics>
<sources>
<source name="System.ServiceModel"
switchValue="Information, ActivityTracing"
propagateActivity="true">
<listeners>
<add name="traceListener"
type="System.Diagnostics.XmlWriterTraceListener"
initializeData= "D:\logs\Traces.svclog" />
</listeners>
</source>
</sources>
</system.diagnostics>

Rerun request, and watch the traces.svclog file appear under logs.

The contents of the logfile looks like this:

<E2ETraceEvent xmlns="http://schemas.microsoft.com/2004/06/E2ETraceEvent"><System xmlns="http://schemas.microsoft.com/2004/06/windows/eventlog/system"><EventID>0</EventID><Type>3</Type><SubType Name="Transfer">0</SubType><Level>255</Level><TimeCreated SystemTime="2010-08-06T07:01:12.0107773Z" /><Source Name="System.ServiceModel" />

This is very verbose and quite unreadable. But then again, XML was never intended for humans…

Time to find a tool that can parse this. In the Windows SDK that is shipped with Visual Studio there is a tool called Service Trace Viewer.

When you start the Service Trace Viewer and load the tracefile that was produced from the WCF Service, you will get a view that looks like this:

Now, the errors that occured in the Service is highlighted in big red letters.

Expanding my bootable VHD

I just love booting from VHD in Windows 7. I have a playground for prerelease software, and just now Microsoft is releasing a torrent of them for the coming 2010 wave.

But the other day the VHD I booted from ran full. The disk is dynamic, but had a max size of 25 GB. After booting back to my physical drive, I tried Disk Management, but there was no option to expand the VHD there. The solution was a two step procedure:

1) Use DISKPART to expand the file:

select vdisk file=c:\vm\example.vhd
expand vdisk maximum=20000

2) Attach the VHD. In Disk Management you will see this:
 
Right-click the volume (F:) and select Extend Volume.

Alternative 2): Complete the process without leaving diskpart. Make sure you you use the correct warning for

attach vdisk
select volume F:
extend filesystem