Steve Spencer's Blog

Blogging on Azure Stuff

Windows Azure Roles Fail to run when deployed to Azure

Recently I was helping out at the Azure Bootcamp in London and during the labs a common theme kept occurring when the labs were deployed to a real Azure account. The roles failed to run and it appeared that the deployment was taking forever.  This is something I experienced first hand when I was starting out with Azure. There is a way to diagnosing these deployment errors and it is by using IntelliTrace. During deployment you can enable IntelliTrace as part of the publish dialog

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The IntelliTrace option is only available if you have Visual Studio 2010 Ultimate. Once deployed to Azure the Roles will attempt to start and any errors during this phase will lead to the symptoms mentioned above. You can then connect to your Azure environment using the Server Explorer in Visual Studio to retrieve the IntelliTrace files which can be opened in Visual Studio and show any exceptions that may have been thrown. Further information can be found here. Once you have diagnosed your issue please ensure at you then disable the IntelliTrace by redeploying the fixed application as it will have a negative impact on performance if left enabled.

 

Getting back to the problem we have at the Bootcamp, the issues was that the deployed application was trying to writing information to Azure storage and the connection string was still pointing to Development storage. This was strange because none of the deployed applications had got to the Azure storage part of the lab so you would have thought that there was no need for a connection string. Luckily I had the exact same problem with one of my earlier deployments and it turns out that when a project is created the Diagnostic plug-in is automatically enabled. The diagnostic plug-in requires its own connection string to Azure storage so that the diagnostic information can be stored. Looking at the role configuration in Visual Studio you can see the Diagnostic plug-in configuration.

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To fix the deployment issue click the button next to the connection string text box and enter the details of your Azure Storage account.

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You will need to redeploy the application or upload the new ServiceConfiguration.cscfg to fix this issue. If this still does not resolve the issue then try disabling the Diagnostics plug-in and redeploy.

Logging with Log4Net

A while ago I was looking for an alternative to System.Diagnostics.Trace and found Log4Net. I know the patterns and practices group have created enterprise logging but I find Log4Net nice and easy to use. I created some documentation and samples on my website at http://www.recneps.co.uk/log4net.aspx.

The BlackMarble.Diagnostics.Logging libraries encapulate both System.Diagnostic.Trace and Log4Net so that we can use a standard way of logging and then configure at runtime one we want to use.