Die wunderbare Welt von Isotopp

Rijksmuseum

Energieverbrauch in Deutschland

Kris Koehntopp picture Kristian Köhntopp - 3rd July 2022
Der Wikipedia-Artikel zum Thema Energieverbrauch ist wirklich interessant. Schaut man sich zum Beispiel diese Grafik (oder die Tabelle, auf der sie basiert) an, dann sieht man: Primärenergieverbrauch Deutschland 1990 bis jetzt Wie man sieht, ist der Primärenergieverbrauch von Deutschland seit…>

I have met the enemy, and they are us

Kris Koehntopp picture Kristian Köhntopp - 1st July 2022
Another Friday, another replication hierarchy lost. The error from June, July edition? The errors reported look awfully familiar: Binlog position is supposedly 4, and the error message has text about "max_allowed_packet". Could it be another instance of this bug from early last…>

The new energy bill

Kris Koehntopp picture Kristian Köhntopp - 28th June 2022
We got our solar roof around 1st of April. I am describing our setup here. Today we got the bill for Summer 2021 to Summer 2022. What I measured I installed a P1 interface on my electricity counter late in April, so my data does not cover all of the lifetime of the Solar Roof. Starting the graph at…>

Jetbrains Remote Development

Kris Koehntopp picture Kristian Köhntopp - 27th June 2022
I am on a Mac or on a Windows machine, and always I have to develop for a Linux target. On Windows, this is easy, because most Jetbrains environment already support working inside WSL2, so simply choosing this is a no-brainer. On MacOS, I can create a "Docker Container" do develop in, but…>

Breaking replication with ALGORITHM = INSTANT

Kris Koehntopp picture Kristian Köhntopp - 20th June 2022
MySQL 8.0.29 adds ALGORITHM=INSTANT as a way to run ALTER TABLE commands with less wait. The documentation can be found in Online DDL Operators and instant column operations can be found here. Example Syntax looks like this: mysql> use kris; mysql> create table t (id serial, d…>

How to buy an e-Bike

Kris Koehntopp picture Kristian Köhntopp - 8th June 2022
I have been asked what kind of bike I ride and how to choose one. Gazelle Grenoble 2017, with vaude Aquaback plus. I am over 50 years old, over 200cm tall and weigh more than 120 kilo before I dresss. Back when we still had an office, that was a 22km trip, each direction. I need an upright sitting…>

Carver S+

Kris Koehntopp picture Kristian Köhntopp - 8th June 2022
After getting a solar roof we have been looking at electric mobility solutions. But existing electrical cars seemed pretty much oversized. We do not really need a 4-seater with 650km range and two tons of total empty weight. Katja Diehl coined the german tongue-in-cheek term…>

Binlog Compression and Large Transactions

Kris Koehntopp picture Kristian Köhntopp - 7th June 2022
(Twitter thread, reproduction in english, and update) On Friday, 2022-06-03, 14:42, we lost a replication hierarchy, on the primary, all replicas down. At 16:30 the escalation hits my desk, because this one is special. Replication stops, and wants more max_allowed_packet There is a sequence of…>

Rolling MySQL back and forward

Kris Koehntopp picture Kristian Köhntopp - 2nd June 2022
Where I work, we manage databases in an automated way. Not as automated as I wish it to be, but largely without touching boxes. We have been doing so for a long time. Over ten years ago, I set the team the challenge "be on an arbitrary version of MySQL within 20 workdays (one calendar month),…>

Wie normale Leute eben...

Kris Koehntopp picture Kristian Köhntopp - 16th May 2022
Der Schnuppel ist jetzt in der niederländischen Groep 8, also in der 6. und letzten Klasse der Grundschule. Die letzten Tests sind geschrieben, die Schulempfehlungen sind raus und bindend, die Folgeschule steht fest und hat die Anmeldung bestätigt. Das Schuljahr ist also noch lange nicht zu Ende,…>

Fertig gelesen: Crafting Interpreters

Kris Koehntopp picture Kristian Köhntopp - 16th May 2022
Robert Nystrom is a language developer who works at Google on the Dart programming language. In his book Crafting Interpreters he explains lexing, parsing and executing a programming language in an accessible way. "Crafting Interpreters", Robert Nystrom Nystrom sets out with the…>

Fertig gelesen: Fietsparkeren bij Stations

Kris Koehntopp picture Kristian Köhntopp - 7th May 2022
The Netherlands realized around 2000 that they have a problem with bike parking around train stations, and with parking around stations in general. A program was set up to fix that, assuming things would be done with in ten years. The program was a great success, and people taking the bike to use…>

Fertig gelesen: Pale Rider

Kris Koehntopp picture Kristian Köhntopp - 6th May 2022
A book from 2017, about the Spanish Flu, which in the wake of the first world war turned into a global pandemic, killing between 50 and 100 million people on all continents. Pale Rider, Laura Spinney Spinney describes the situation in the world in 1918, and how the Spanish Flu came into the world,…>

Fertig gelesen: The Kaiju Preservation Society

Kris Koehntopp picture Kristian Köhntopp - 5th May 2022
On an alternate earth alternate biology produces beings that can grow up to 150 meters tall and that are powered by natural biological nuclear reactor: The Kaiju. Whenever anything, humans or Kaiju, uses nuclear energy, the boundary between the alternate realities is weakened and things can cross…>

Fertig gelesen: Sid Meier's Memoir!

Kris Koehntopp picture Kristian Köhntopp - 4th May 2022
The subtitle of "Sid Meier's Memoir!" is "A Life in Computer Games". And that is exactly what we get: Sid Meier lists, chronologically and very systematically, all the games he has been working on during his lifetime. And tells us what happened to him, the game and the game…>

Fertig gelesen: The Pattern on the Stone

Kris Koehntopp picture Kristian Köhntopp - 3rd May 2022
This is an old book, from 1998, and much of the technology referred to directly has evolved since then. But, as this a book that deals with basics, in terms of metaphor and analogy, it is still valuable. It explains how computers work, and how we make the tech that powers them. The Pattern on the…>

A solar roof

Kris Koehntopp picture Kristian Köhntopp - 2nd May 2022
I live in a house in a rural village somewhere in Randstad. We are paying around 70 Euro per month in electricity, and up to 380 Euro per month in gas. We are using the latter for heating and warm water, but we are already cooking with electricity. The house has a decent energy rating and a heat…>

Fertig gelesen: The Undersea Network

Kris Koehntopp picture Kristian Köhntopp - 2nd May 2022
Where is the Internet coming from and how and when was it built? It's a network of tubes, or rather cables, and these days they are mostly fiber. Much of it was built during the dotcom boom, but little has been written. The Undersea Network, Nicole Starosielski Nicole Starosielski is a professor…>

SQL Engineering Guidelines

Kris Koehntopp picture Kristian Köhntopp - 15th April 2022
Where I work, the native database is MySQL. This is what the database team fully supports. Other databases, notably Postgres, are in use mostly because external products we run require them. Internal projects should use MySQL. An external company provides limited support for running Postgres. The…>

DevOps meets Databases

Kris Koehntopp picture Kristian Köhntopp - 4th April 2022
On Twitter, Samuel Nitsche asked: Are there "IT history nerds" on this app? Like people who have the skills/knowledge to tell how some trends/evolutions in IT appeared? I'd love to connect! Asking about what he wanted to know specifically he said, he's interested in the reasons why…>
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