Skip to main content

Azure Development Environment - Event Hub and Throughput Units

Very often, the cloud services that are cheap are the one that will be the most expensive one at the end of the month. Not because there are hidden costs, but because people tend to use them without caring of costs - they say that are cheap and the price is low.
Making a review to the last bill of the development subscription I notified that 25% of the costs of the bill are generated by Service Bus - more exactly by Event Hub.

Event Hub
Why this is happening? Each developer is using one or two instances of Event Hub to develop, test and validate different flows. Our scripts, that are generating instances of Event Hub will crease a new namespace for each new instance of Event Hub.
In this context, for a team of 7 developers, you will end up with 14 different Event Hubs and Service Bus Namespaces. On top of this, you will have different environments, like DEV and TEST environment that will add another 3 or 4 instance of Event Hubs.
In the end you can end up with 18 different Event Hubs, each instance will have his own namespace and Throughput Unit.

The cost of a Throughput Unit (TU) per month is around 22$ for the Standard tier.
18TU x 22$ = 396$/mo
Nice, almost 400$, only for TU.

Keep in mind
Before describing each solution that could help us optimize the cost, we need to remember that if you implement a solution, it should have a low impact on development team. This means that you don't want to make the DEV life a hell, because you decided to reduce some costs.
If might cost you more the time that DEV team lose by sharing the same Event Hub or implement another solution that optimize costs than the TH cost itself.

Possible Solution
It might be possible for each DEV to use only one Event Hub and have multiple Consumer Groups. This solution is not only complex, but will not be 1 to 1 to the real environment and can be buggy.
I would try to avoid as much as possible a solution like this.
Use Basic Tier
The cost difference between Standard and Basic tier is 50% per TU (Basic is 11$/mo, Standard is 22$/mo). The problem with the Basic tier is from the functionality that is available, like Publisher Policies or the number of Consumer Groups.
The one that might create the biggest problem is the limited number of Consumer Groups. For nasic tier you can have only one, the default one - $Default. This default Consumer Group cannot be renamed or deleted. If you need a custom name of the Consumer Group you will not be able to use the Basic tier.
Because we are using custom name for Consumer Groups, we cannot use this solution without changing the deployment and creation script.
Clean the Event Hub every day
This solution would involve that each day, to delete all the DEV instances of Event Hub and in the morning to recreate it. The price of TU is per hour so you might be able to reduce the cost with maximum 50%.
From my past experience I would say that you will be able to reduce the cost only with 33%. Why? Because people might come at 8AM, others might leave at 8PM. So you will need around 16 hours when the resources is up and running.
From the DEV perspective, you will need a script to clean and recreate resources and also to push the access configuration to their environments.  This might be a hell, creating a to complex and buggy DEV env. that will cost you more and will not be loved by the DEV team.
I wouldn't try to implement such a solution.

Even if we identified different solutions that might help us to reduce the cost of the bill, we need to decide if worth it or not to optimize the cost.
Personally, I wouldn't do any change related to this and I would prefer to pay more on Azure bill, but have a simple and clear DEV environment, that is easy to use.


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…