Skip to main content

Service Bus - Optimize consumers using prefetch and maximum concurent calls features

From same version ago, Windows Azure Service Bus supports 'event notification'. This means that we can register to an event that will be triggered each time when a new message is available for us.
QueueClient client = QueueClient.Create("queue1");
    new OnMessageOptions());
void OnMsgReceived(BrokeredMessage message)

This is a great feature, that usually make our life easier. By default, when we are consuming messages in this way, we will make a roundtrip to the Service Bus for each message. When we have applications that handle hundreds of messages, the roundtrip to the server for each message can cost us time and resources.
Windows Azure Service Bus offer us the possibility to specify the number of messages that we want to prefetch. This means that we will be able to fetch 5, 10, 100, .. messages from the server using a single request. We could say that is similar to the batch mechanism, but can be used with the event notification feature.
QueueClient client = factory.CreateQueueClient("queue1");
client.PrefetchCount = 200;
We should be aware that the maximum numbers of messages that can be prefetch by one request is 200. I think that this an acceptable value, if we take into the consideration that this will trigger 200 notification events.
This value need to be set when we create and setup the subscription client. Theoretically you can set this value before receiving the first message from the server, but I recommend to make all this configuration at the setup and initialization phase.
When we are using this mechanism of prefetching, we need to know exactly how many concurrent calls  we can have. Because of this, the Service Bus client give us the possibility to specify how many concurrent calls we can have in the same time.
client.OnMessage(CalculateEligibility,new OnMessageOptions()
                MaxConcurrentCalls = 100
For example if we would have the prefetch count set to 200, and the maxim concurrent calls sett to 100, we will have the following behavior:
Make a roundtrip to the server
Receive 200 messages (we suppose that there are 200 messages available)
Consume first 100 messages
Consume the other 100 messages
Messages are consumed in a async way. This means that from the first 100 messages, when 1 will be processed on the client, another message receive event will be triggered.
We saw in this post how we can consume the messages in parallel when using Windows Azure Service Bus and event notification. Using this features we can increase our application performance.
Good luck with Windows Azure Service Bus.

PS: Bonus picture - This is a picture from Seattle airport, where I am now, waiting the flight back home.


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 …

How to check in AngularJS if a service was register or not

There are cases when you need to check in a service or a controller was register in AngularJS.
For example a valid use case is when you have the same implementation running on multiple application. In this case, you may want to intercept the HTTP provider and add a custom step there. This step don’t needs to run on all the application, only in the one where the service exist and register.
A solution for this case would be to have a flag in the configuration that specify this. In the core you would have an IF that would check the value of this flag.
Another solution is to check if a specific service was register in AngularJS or not. If the service was register that you would execute your own logic.
To check if a service was register or not in AngularJS container you need to call the ‘has’ method of ‘inhector’. It will return TRUE if the service was register.
if ($injector.has('httpInterceptorService')) { $httpProvider.interceptors.push('httpInterceptorService&#…

Fundamental Books of a Software Engineer (version 2018)

More then six years ago I wrote a blog post about fundamental books that any software engineer (developer) should read. Now it is an excellent time to update this list with new entries.

There are 5 different categories of books, that represent the recommended path. For example, you start with Coding books, after that, you read books about Programming, Design and so on.
There are some books about C++ that I recommend not because you shall know C++, only because the concepts that you can learn from it.


Writing solid codeCode completeProgramming Pearls, more programming pearls(recommended)[NEW] Introduction to Algorithms


Refactoring (M. Fowler)Pragmatic ProgrammerClean code[NEW] Software Engineering: A Practitioner's Approach[NEW] The Mythical Man-Month[NEW] The Art of Computer Programming


Applying UML and Patterns (GRASP patterns)C++ coding standards (Sutter, Alexandrescu)The C++ programming language (Stroustrup, Part IV)Object-oriented programming (Peter Coad)P…