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CAP Theorem, CQRS and Eventually Consistent

First, if you haven’t heard of Eric Brewer’s CAP theorem, it basically states that you can must choose two of three: Consistency Availability Partition Tolerance CQRS doesn’t solve CAP issues, however it allows you to decide independently what is important on both read and write side. For example, you could assume a systems would be ACID (Atomic, Consistent, Isolated, Durable) compliant on the write/domain site and BASE (Basic Availability, Soft-State, Eventually Consistent) on the read side. Eventual consistency is something that requires a change of mindset.  Because of our heavy use in ACID compliant databases, thinking about possibly having stale data blows our mind. There… Read More »CAP Theorem, CQRS and Eventually Consistent

Greg Young: 8 Lines of Code

Greg Young gave a good talk titled 8 Lines of Code, discussing simplicity, dependencies, and magic. Magic is always something I try and identify and stay away from in my own code, however I really failed to realize how much magic goes on in some of the libraries/frameworks that I often use.  Entity Framework and nHibernate come to mind.  You really should understand the magic happening in these libraries to use them.  Which is very problematic. If you take the dependency ownership seriously, then a lot of folks developing the front-end of a “modern” web applications are in a world of… Read More »Greg Young: 8 Lines of Code

Microsoft Fakes (formerly Moles)

Problem: You are writing unit tests that involve a dependency on a 3rd party concrete class. Unfortunately there are no interfaces, nor are the methods/properties defined as virtual. Solution: Microsoft Fakes (formerly Moles) Microsoft Fakes help you isolate the code you are testing by replacing other parts of the application with stubs or shims. These are small pieces of code that are under the control of your tests. By isolating your code for testing, you know that if the test fails, the cause is there and not somewhere else. Stubs and shims also let you test your code even if other parts of your application are… Read More »Microsoft Fakes (formerly Moles)