A simple performance comparison between approaches encouraged by F# (immutability and functional programming) and C# (mutability and OOP). Which one would you choose?

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Reading time ~4 minutes This post is an analysis of a very interesting optimization proposed by Nicholas Frechette in the comments under the previous post. He proposed to use one of the oldest tricks in performance cookbook - divide and conquer. Well, it did not turn out as I expected.Saga Before I go further here are some link to the previous posts on the problem of calculating similarities and then optimizing. This thread grew to a few post. Here are all of them:How I calculate similariti...

Reading time ~2 minutes This post was inspired by a discussion on Reddit that followed my previous post In this post, I will cover a suggestion by BelowAverageITGuy that cut down the total execution time by almost one hour. Saga Before I go further here are some link to the previous posts on the problem of calculating similarities and then optimizing it grew to few post. Here are all of them:How I calculate similarities in cookit?How to calculate 17 billion similaritiesIndependent code in ...

Reading time ~6 minutes Last time I’ve shown how I’ve gone from 34 hours to 11. This time we go faster. To go faster I have to do less. The current implementation of Similarity iterates over one vector and checks if that ingredient exists in the second one. Since those vectors are sparse the chance of a miss is big. This means that I am losing computational power on iterating and calling TryGetValue. How to iterate only over the mutually owned ones and do it fast? Saga Before I go furth...

Attribute routing (RouteAttribute) is a quite handy feature of ASP.NET MVC. It allows you to have nice looking URLs that everybody has already accustomed to and your client surely loves it. Plus it hides your true controller/action structure which sometimes might be desirable. But there's one catch. As your web app gets bigger and bigger, attribute routing might have a negative performance impact on your WHOLE website.

Kontynuując wątek LINQ, który podjąłem jakiś czas temu, poruszę dziś temat optymalizacji operacji jakie wykonujemy na kolekcjach. Na starcie muszę się przyznać, że tytuł nie jest do końca zgodny z prawdą, bo trzy słowa to o wiele za mało, by wejść w głębiej w temat optymalizacji zapytań. Są jednak 3 metody, które można wykorzystać do znacznego przyspieszenia wykonywania operacji w bardziej rozbudowanych łańcuchach przy minimalnym nakładzie pracy.

Reading time ~2 minutes I’m taking a short break from Hangfire series, but I will get back to it. This time - Where did my memory go ? Or to be more exact: Why is this using so much memory? The story starts with one IIS application pool using around 6 Gigabytes of memory on one of our test environments. It was several times above the values that we expected it to use, so we decided to investigate. Without much thinking we fired up Visual Studio installed on the test server, and attached to the proce...

Imagine that you have a service, which receives requests to execute specific methods, possibly from a number of different underlying libraries that you don’t want to expose directly. Possible examples are web services. The request comes in as a number of string values (method name, parameters etc.) and you need to respond with results. So you have inherited a project with API that starts with a method: object Invoke(string methodName, object[] parameters); You now have to call variety o...

One of the steps in cookit is calculating similar recipes. This is what you can see on the left on the recipe page like this For the sake of clarity and manageability it’s scheduled as separate Hangfire jobs. Because cookit is running 5 workers, so similarities are calculated for 5 websites concurrently. The process uses cosine similarity, so it allocates a huge list at start and calculates similarities. A very CPU heavy operation. So some time after triggering all recipes recalculation I saw this in...