Diagnostics not working in Web Role for Azure SDK 2.5.1

I am working with Azure SDK 2.5.1, mainly on newly developed diagnostic material. However, I found that I cannot start it for my web role.

So I created a cloud services project, added a web role. Then I added one Trace message at the end Application_Start

in Global.asax.cs

:

Trace.TraceInformaction("Application_Start end.");

      

        
        
        
      

    

After that, I right clicked on the WebRole and opened the tab Properties

. In the diagnostic configuration window:

• General . I choose 'Custom plan'
  
  also specifying the storage account, keeping 'Disk Quota in MB'
  
  the default'4096'
  
  
• Application logs : 'Log level'
  
  go to 'All'
  
  , others are saved as default
• Other tabs are in the default configuration settings.

After deploying the project to the cloud, I found some unexpected things:

• There are no tables in the store WADLogsTable
  
  . Very strange, if I use the Worker role, it works as expected. So, in an internet role, I just can't find the trace log?
• For the performance counters, since I'm using the default configuration with 8 counters, I can only see 8 in the table store WADPerformanceCountersTable
  
  . My guess is that over time there will be more and more values ​​of these 8 counters transferred to this table. But this did not happen, after a few hours there were still 8 counter values.

I just thought the diagnostics for the web role just crashed or not working at all. Meanwhile, I checked the logs located in "C:\Logs\Plugins\Microsoft.Azure.Diagnostics.PaaSDiagnostics\1.4.0.0\DiagnosticsPlugin.log"

on the server, there is an exception at the end of this file, said that some diagnostic process has finished:

DiagnosticsPlugin.exe Error: 0 : [4/25/2015 5:38:21 AM] System.ArgumentException: An item with the same key has already been added.
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at Microsoft.Azure.Plugins.Diagnostics.dll.PluginConfigurationSettingsProvider.LoadWadXMLConfig(String fullConfig)
DiagnosticsPlugin.exe Error: 0 : [4/25/2015 5:38:21 AM] Failed to load configuration file
DiagnosticsPlugin.exe Information: 0 : [4/25/2015 5:38:21 AM] DiagnosticPlugin.exe exit with code -105

      

        
        
        
      

    

From MSDN, the code -105

means:

Diagnostics plugin cannot open Diagnostics configuration file.

This is an internal error that should only happen if the Diagnostics plug-in is manually called incorrectly on the virtual machine.

It doesn't make sense, I haven't done anything for the virtual machine.

As I said above, I just made very minor changes to the scaffold code generated by Visual Studio 2013. Did I do something wrong or is this a bug for the Azure SDK 2.5?

By the way, it seems that everything is fine for a worker role.