Skip to main content

Trace information to Windows Azure Azure Tables

I saw that there are a lot of people that use tracing infrastructure that is offered by .NET framework to trace information in Windows Azure Tables. Basically, after we configure the configuration file, the only thing that we need to do is to call the Trace class and write data to it.
Trace.WriteLine(“Some  trace data”);
Trace.TraceWarning(“Some worning information”);
Trace.TraceError(“An error that appeared in the application.”);
We can do a log of thinks with this class. It is not something new.
In the configuration file of our application we need to add a new trace listener that is able to write all the trace information to Azure Tables.
        <add type="Microsoft.WindowsAzure.Diagnostics.DiagnosticMonitorTraceListener, Microsoft.WindowsAzure.Diagnostics”  name="DiagToAzureTables"></add>
Next step is to add the listener to the trace listener collection each time when your application start. At this step I prefer to set auto-flush to true. In this way all the content will be send automatically to the trace and the risk to lose data when the machine is instable and crash is very low.
System.Diagnostics.Trace.AutoFlush = true;
On the internet you will find a lot of implementation of trace listener. The one that I prefer to use is the most common one. One of the implementation can be found in the following location
If we check the Azure Tables of our account we will see that a new table was created with the following structure:
  • PartitionKey - D10 of event timestamp >> 30
  • RowKey - D19 of event timestamp
  • EventTickCount – event timestamp
  • Level - event type
  • EventId – event id,
  • Pid - event process id
  • Tid - event thead id
  • Message - event message
After a time you will observe that the EventTickCount can have different values, that are not orders based on the timeline. This is happen because the event timestamp is based on Stopwatch.GetTimestamp() method. This method don’t guaranty to us that will get a higher value in time. The purpose of Stopwatch is to measure time interval and calling GetTimestamp method return the current value of the counter (this is not correlated with the current date of the system) -
is correlated to the time when the system/process have been started.
Remarks: Base on the hardware configuration we can have a frequency tick per second or per nanoseconds. We can determine what is the frequency using StopWatch.Frequency.
If we want to order events based on the event tick count, we need to be aware that this will be valid only for events that were generated by the same processor (Pid). For different processor on the same machine the EventTickCount can be different.
Never try to order all the event of a Trace table from Windows Azure based on the EventTickCount. You can use it in combination with Pid. Also, the TimeStamp column of Azure Table store the time when the message was written to Azure Table and not the moment when the event was generated.


  1. Nice, but why would want somebody to do this, instead of using the built-in Diagnostics Monitor, which anyway will periodically transfer the collected data to azure tables? (

    I wouldn't want to have an Azure application that will usually have hundreds of role instances, all writing directly to a table storage service ..


Post a Comment

Popular posts from this blog

ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded

Today blog post will be started with the following error when running DB tests on the CI machine:
threw exception: System.InvalidOperationException: The Entity Framework provider type 'System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer' registered in the application config file for the ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded. Make sure that the assembly-qualified name is used and that the assembly is available to the running application. See for more information. at System.Data.Entity.Infrastructure.DependencyResolution.ProviderServicesFactory.GetInstance(String providerTypeName, String providerInvariantName) This error happened only on the Continuous Integration machine. On the devs machines, everything has fine. The classic problem – on my machine it’s working. The CI has the following configuration:

TeamCity.NET 4.51EF 6.0.2VS2013
It seems that there …

GET call of REST API that contains '/'-slash character in the value of a parameter

Let’s assume that we have the following scenario: I have a public HTTP endpoint and I need to post some content using GET command. One of the parameters contains special characters like “\” and “/”. If the endpoint is an ApiController than you may have problems if you encode the parameter using the http encoder.
using (var httpClient = new HttpClient()) { httpClient.BaseAddress = baseUrl; Task<HttpResponseMessage> response = httpClient.GetAsync(string.Format("api/foo/{0}", "qwert/qwerqwer"))); response.Wait(); response.Result.EnsureSuccessStatusCode(); } One possible solution would be to encode the query parameter using UrlTokenEncode method of HttpServerUtility class and GetBytes method ofUTF8. In this way you would get the array of bytes of the parameter and encode them as a url token.
The following code show to you how you could write the encode and decode methods.

Entity Framework (EF) TransactionScope vs Database.BeginTransaction

In today blog post we will talk a little about a new feature that is available on EF6+ related to Transactions.
Until now, when we had to use transaction we used ‘TransactionScope’. It works great and I would say that is something that is now in our blood.
using (var scope = new TransactionScope(TransactionScopeOption.Required)) { using (SqlConnection conn = new SqlConnection("...")) { conn.Open(); SqlCommand sqlCommand = new SqlCommand(); sqlCommand.Connection = conn; sqlCommand.CommandText = ... sqlCommand.ExecuteNonQuery(); ... } scope.Complete(); } Starting with EF6.0 we have a new way to work with transactions. The new approach is based on Database.BeginTransaction(), Database.Rollback(), Database.Commit(). Yes, no more TransactionScope.
In the followi…