Azure WadLogsTable contains duplicate entries

Question

I have a web role (2 instances) and a worker role (2 instances) both roles use the following configuration

        DiagnosticMonitorTraceListener tmpListener = new DiagnosticMonitorTraceListener();
        System.Diagnostics.Trace.Listeners.Add(tmpListener);
        string wadConnectionString = "Microsoft.WindowsAzure.Plugins.Diagnostics.ConnectionString";
        CloudStorageAccount storageAccount =
        CloudStorageAccount.Parse(RoleEnvironment.GetConfigurationSettingValue(wadConnectionString));

        RoleInstanceDiagnosticManager roleInstanceDiagnosticManager =
        storageAccount.CreateRoleInstanceDiagnosticManager(RoleEnvironment.DeploymentId,
        RoleEnvironment.CurrentRoleInstance.Role.Name, RoleEnvironment.CurrentRoleInstance.Id);

        DiagnosticMonitorConfiguration config = roleInstanceDiagnosticManager.GetCurrentConfiguration();
        config.Logs.BufferQuotaInMB = 500;
        config.Logs.ScheduledTransferPeriod = TimeSpan.FromMinutes(1D);
        config.Logs.ScheduledTransferLogLevelFilter = LogLevel.Information;

        roleInstanceDiagnosticManager.SetCurrentConfiguration(config);

When I add some messages I notice that the worker role logs the same entry twice. Do I have to change something?

Answer 1

Thanks for the notice, I will glady repost my hint here as an answer again:

Some project templates in Visual Studio already register an instance of AzureDiagnosticMonitorTraceListener to the Trace.Listeners Collection. You might want to check if there is such a listener already registered before adding a new one:

if (Trace.Listeners.OfType<AzureDiagnosticMonitorTraceListener>().Count() == 0)
{
    Trace.Listeners.Add(new AzureDiagnosticMonitorTraceListener());
}