On Stateless Microservices

This post discusses the stateless microservice design pattern; it is meant as support material for other posts of mine that discuss microservices, mainly michael.gr - The Stateful Microservice.

Is statelessness a requirement for a microservice?

In another post (see michael.gr - So, what is a Microservice, anyway?) I examine what a microservice really is, and I come to the conclusion that from a purely technical standpoint, a working definition could be as simple as this:

A microservice is a scalable and resilient module.

Even if you disagree with the terseness of this definition, and you regard microservices as necessarily more than that, I hope you will at least agree that it is precisely scalability and resilience that statelessness in microservices aims to address, so this definition serves its purpose at least in the context of this series of posts.

There are many who will try to convince you that in order to build a scalable and resilient system, you need statelessness; so much so, that microservices have almost come to be regarded as synonymous with statelessness. This post examines whether this is that in fact so, and what is the cost of doing things this way.

So, what is a Microservice, anyway?

This article attempts to shed some light on what a microservice really is; it is meant as support material for other posts of mine that discuss microservices, mainly michael.gr - The Stateful Microservice.

What is a microservice?

If you go looking for information on what a microservice is, you will find many different descriptions, exhibiting considerable difference of opinion. Most claims about microservices are non-technical rather than technical, for example the allegedly "independent" software development style around microservices, or some alleged organization of microservices "around business capabilities". Even when the claims do stick within the technical realm, they are often unwarranted; for example, I have seen statements to the effect that a microservice is supposed to live in its very own source code repository, that microservices must communicate with each other via nothing but REST, etc. My favorite one is that they must necessarily be stateless. This paper is a first step in dispelling the statelessness myth.

What is wrong with Scala

This is part of a series of posts in which I am documenting what is wrong with certain popular programming languages that I am (more or less) familiar with.  The aim of these posts is to support a future post in which I will be describing what the ideal programming language would look like for me.  

I will be amending and revising these texts over time.

What is wrong with C#

This is part of a series of posts in which I am documenting what is wrong with certain popular programming languages that I am (more or less) familiar with.  The aim of these posts is to support a future post in which I will be describing what the ideal programming language would look like for me.  

I will be amending and revising these texts over time.

What is wrong with Java

This is part of a series of posts in which I am documenting what is wrong with certain popular programming languages that I am (more or less) familiar with.  The aim of these posts is to support a future post in which I will be describing what the ideal programming language would look like for me.  

I will be amending and revising these texts over time.

What is wrong with C++

This is part of a series of posts in which I am documenting what is wrong with certain popular programming languages that I am (more or less) familiar with.  The aim of these posts is to support a future post in which I will be describing what the ideal programming language would look like for me.  

I will be amending and revising these texts over time.

[SOLVED] In Windows, how to recover an invisible application window

Scenario:

• You are using a laptop with one or more external monitors at home and (a different set of external monitors) at the office.

Problem:

• Every once in a while, when you switch between home and office, some buggy application will not handle its screen positioning correctly, so it will open up off-screen. In the taskbar you can see that the application has launched, but the application window is invisible.

How to fix:

Malicious Inaction

Actor Wayne Knight in the original Jurassic Park movie
playing the role of the unscrupulous programmer Dennis Nedry,
(anagram of "Nerdy",) the main villain.

Malicious Inaction (noun) any situation where a piece of software encounters an unexpected condition and responds by deliberately doing nothing, including not throwing an exception.  Synonyms: Silent Failure; Deliberate Malfunction; Unscrupulous Programming; Undermining; Sabotage; Treachery; Subversion; Vandalism.

I think that the term "Silent Failure" fails to express the amount of harm done.  Sure, the word "failure" indicates that something went wrong, but the word "silent" somewhat lessens the severity of the term, and it makes sound as if no feathers were ruffled, so it may have been alright.

Well, no. It was not alright. It never is. We need a stronger term to better capture the harm caused by the sinister practice of hiding error. We need a term that clearly conveys wrongdoing, a term that assigns blame and shame.

Hence, I present to the world my new and improved term: Malicious Inaction.

"Lifeboat of the week" from Stack Overflow

The Stack Overflow blog podcast 312 (of 2021/02/12) "We're building a web app, got any advice?" awarded me with what they call a lifeboat! 

SVG in WPF

My notes on how to use SVG graphics in a WPF application

The Goal

The goal is to be able do do things like this:

    <Button Content="{StaticResource mySvgImage}">

... where mySvgImage somehow stands for a vector image that has somehow been obtained from an SVG file.  

The solution must not involve any proprietary, closed-source libraries.

Naturally, we want one of the following:

• either directly include SVG files into our application as resources, or, if that is not possible, then 
• have an "asset pipeline" approach where our SVG files are automatically converted during build into some format which is suitable for inclusion as a resource.