Skip to main content

How to monitor clients that access your blob storage?

Some time ago I wrote about the monitor and logging support available for Windows Azure Storage. In this post we will talk about how we can use this feature to detect what clients are accessing storage.
Let’s assume that we have a storage that is accessed by 100.000 users. At the end of the month we should be able to detect the users that downloaded a specific content with success.
What should we do in this case?
(Classic Solution) Well, in a classic solution, we would create an endpoint that will be called by the client after he download with success the specific content. In this case we would need to create a public endpoint, hosted it, persists the calls messages, manage and maintain the solution and so on.
In the end we would have additional costs.


What should we do in this case?
(Windows Azure Solution) Using Windows Azure Storage, we can change the rules of the game. Windows Azure Storage offer us out of the box support for logging mechanism. All the request that are made to our storage will be logged.

Based on this idea, we activate this feature and log all the access to the storage. In the following example you can see how the logs look like for a file called ‘m.txt’ under a container named ‘container’.
1.0;2013-11-12T13:03:23.4277012Z;GetBlob;AnonymousSuccess;200;7;7;anonymous;;radudemo;blob;"http://radudemo.blob.core.windows.net/container/m.txt";"/radudemo/container/m.txt";98ebc2d2-249f-47d2-8a3b-e7bbcb5e3c59;0;86.124.100.155:21131;2009-09-19;379;0;284;7;0;;;"0x8D0ADBEAF6D6A3C";Tuesday, 12-Nov-13 13:03:15 GMT;;"Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36";;
As you can see, we have all the necessary information to identify the client, inclusive the client IP. But we want to do more than that. We want to be able to detect clients based on aware own identification mechanism.
To be able to do something like this, we have to options:
Query parameters
We can add a custom query parameter that represent the client unique ID. For example we can make the following requests
http://radudemo.blob.core.windows.net/container/m.txt?clientID=123
In this case, the client will receive the file and in the logs we will have:
1.0;2013-11-12T13:03:36.3117012Z;GetBlob;AnonymousSuccess;200;14;14;anonymous;;radudemo;blob;"http://radudemo.blob.core.windows.net/container/m.txt?clientID=123";"/radudemo/container/m.txt";c90e928f-f3e7-4c4f-859b-4bb0051f0271;0;86.124.100.155:21131;2009-09-19;392;0;284;7;0;;;"0x8D0ADBEAF6D6A3C";Tuesday, 12-Nov-13 13:03:15 GMT;;"Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36";;
In the client URL we can find the clientID that can be filter, processed and so on.
User Agent
Another option is to set a custom user agent. Using a custom user agent it will be very easily for us to identify witch client made the requests.
1.0;2013-11-12T13:03:36.3117014Z;GetBlob;AnonymousSuccess;200;14;14;anonymous;;radudemo;blob;"http://radudemo.blob.core.windows.net/container/m.txt";"/radudemo/container/m.txt";c90e928f-f3e7-4c4f-859b-4bb0051f0271;0;86.124.100.155:21131;2009-09-19;392;0;284;7;0;;;"0x8D0ADBEAF6D6A3C";Tuesday, 12-Nov-13 13:03:15 GMT;;"Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36 ClientID/123";;

Both solutions are similar, we are only sending the unique client id in different locations. This files can be very easily processed and analyzed using different solutions. A good solution when you have a lot of logs file is by Hadoop.
The advantages of using such a solution is the out of the box support. You don’t need to create and manage another system for this. Also you eliminate the case when the client is able to download/access the content but is not able to confirm the download.
The only additional costs that are added to a classic solution is the storage cost for storing the logs data itself, plus the transactions costs. This costs are very low in comparison with the case when you would create all the infrastructure for logging. In both cases you would need to pay the storage costs of logs.

Comments

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 http://go.microsoft.com/fwlink/?LinkId=260882 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 …

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…

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.
publ…