Hello, I am Laszlo

Null-coalescing Operator vs. Equals - Equals

08/31/2019

I have been asked the following question over-and-over: which solution is the faster and better to use in the condition part of the if keyword, to branch based on a property which might be defined on a nullable reference type:

• to use the null-coalescing operator (??)

• or the equals operator (==)

To give some context let's assume that we branch our code based on a reference type's bool property:

public class SomeClass
{
    public bool Condition { get; set; }
}

Find out more

Generating image to IoT DevKit with Azure Durable Functions

08/28/2019

I have recently bought an IoT DevKit AZ3166, and playing with it a lot. First, it is a lot of fun. Secondly, it has a good documentation and project catalog to get started in no time. Thirdly, do not try to upload code to the device through and RDP session, that just does not work.

This post will show how I generate a graph in a Durable Function and display it on the IoT DevKit.

Getting Started with IoT DevKit

Find out more

Mid-Life Crisis and Polly

07/17/2019

Problem

I have been working on an application sending out millions of HTTP Post requests. The application has an issue, it has a high memory usage. It is using 2 GB over the expected of a few hundred megabytes.

An investigation revealed that a percentage of (random) requests are failing because of invalid request content. When a request fails, the application has a built in resiliency policy to wait with an exponential backoff and retry the failed requests. Unfortunately, that failed request is determined to fail again, hence triggering the above policy 3 times, before giving up for all.

One could figure, that the retry policy is referencing the failing requests for considerably longer period in memory. Let's not trust our gusts but do some measurements instead.

Find out more

Animating Graph on Azure IoT DevKit

07/03/2019

In the previous post I have shown how an image can be generated by an Azure Function and sent to IoT DevKit to display it.

In this post, I will show how that given image can be animated on the device.

The goal is to animate the graph from left to right, so it shows the measurements first closer to the y-axis, and the one further (to the right) only at a later time. I am not going to propose a generic animation algorithm, but rather an efficient and specific to this problem.

Find out more

Personality Chat Integration to Bots

05/16/2019

There is a library and service called Personality Chat that can be integrated to a chat bot so add small talk capabilities. The interesting part of it is that you can provide a personality type like professional, friendly, humorous.

I have a LUIS chat bot, so it is an exciting option to me to integrate this capability to my bot. I have been using BotBuilder v4 SDK, and Personality Chat provides an integration point with that too. Integration itself seems simple, based on the provided samples and documentation, all you need is to setup a middleware for your bot during startup.

Tryout

The real story is a bit more involved, hence this post is born. The current status of the library is an alpha nuget package. It is referencing an alpha build of the BotBuilder v4 SDK too, which contains breaking changes. For this reason, you won't be able to add middleware to your bot, you will get a compile error.

Find out more