I’ve mentioned a bit about the attributing the handler and the step and timing parameters, but I’ve not explained them properly in previous posts (“Retrying commands” mentions steps, and “Don’t Repeat Yourself” also mentions timings). So, I’ve created a small project to demonstrate what they mean and how it all operates. The code for this …
Continue reading “Paramore Brighter: The Russian Doll Model”
You may wish to add similar functionality to many (or all) command handlers. The typical example is logging. You can decorate a command handler in a similar way to the policies I showed in previous posts to add common functionality. I’ve used this technique to guard the handler from invalid command arguments/parameters (essentially a validator), …
Continue reading “Paramore Brighter: DRY with Custom Decorated Command Handlers”
Paramore Brighter supports Policies to maintain quality of service. This is useful when your command makes calls to external services, whether they are databases, web services, or any other end point that exists out of the process of your application. You can set up retry policies, circuit-breaker policies, and timeout policies. For this post, we’ll …
Continue reading “Paramore Brighter with Quality of Service: Retrying Commands”
So far in this series, we have a basic command processor set up and able to dispose of resources. But what happens when things go wrong? The command processor has a fallback mechanism to handle exceptions that are not caught. To add this functionality all you need to do is to decorate your handler with …
Continue reading “Paramore Brighter: Implementing a fallback exception handler”
We recently had need of a round robin functionality and since there is no round robin class built into .NET I needed to build my own class. It is a fairly simple algorithm, each call returns the next item in the sequence. When the end of the sequence is reached go back to the beginning …
Background Recently, I had a bit of a problem with NHibernate when I was converting some code into parallel tasks. (If you have no interest in NHibernate, then don’t worry – it is just background to the issue I was having when I spotted this gulf between my expectation and reality. NHibernate is incidental to …
Continue reading “But why is the iterator operating in multiple-threads”
Sometimes it is rather difficult to debug through Visual Studio directly even although the project is right there in front of you. In my case I have an assembly that is invoked from a wrapper that is itself invoked from an MSBuild script. I could potentially get VS to invoke the whole pipeline but it …
Continue reading “Debugging a process that cannot be invoked through Visual Studio.”
In .NET 4.5 three new attributes were introduced. They can be used to pass into a method the details of the caller and this can be used to create better trace or logging messages. In the example below, it outputs tracing messages in a format that you can use in Visual Studio to automatically jump …
Here is a curious gotcha using the Entity Framework: If you are filtering on a value that may be null then you may not be getting back the results you expect. For example, if you do something like this: var result = context.GarmentsTryOns .Where(gto => gto.WeddingId == weddingId && gto.PersonId == personId); And personId is …
If you send to an email that does not exist, Amazon SES will perform some handling of the bounce before passing the details on to you. When you send email through Amazon SES you may notice that the email arrives with a Return Path that looks something like this: 00000331b8b1d648-b8302192-701f-124d-a1d5-d268912677de-135246@email-bounces.amazonses.com As it happens, the large …
