On November 6 2024 I presented a talk with the title: “The implementation of MariaDB parallel replication” at a local TeqHub meetup in Copenhagen. In the talk I first presented how MariaDB replication works overall. I then described the central idea of optimistic parallel replication. Finally I described three details of the implementation: transaction scheduling;… Continue reading Talk: The implementation of MariaDB parallel replication
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Starting as Chief Architect Replication with MariaDB Foundation
Here on August 1st, I am joining the MariaDB Foundation in a position as Chief Architect Replication. Who am I? I am a long term MariaDB developer; in fact I was one of the very first to join Monty in starting MariaDB back in 2009 (I think Sanja may have beaten me by a few… Continue reading Starting as Chief Architect Replication with MariaDB Foundation
EU-parlamentsvalget – undgå at støtte en corona-galning
Der mangler alvorligt selvransagelse efter regeringens og folketingets katastrofale politiske kurs i 2020-2022. Lad os huske på de sørgeligt ringe resultater: Vi skulle “forhindre smitte”. Men fakta er at stor set hele befolkningen blev smittet med covid. 70% er bekræftet smittet, og hertil kommer tilfælde hvor folk ikke er blevet testet. Der blev talt om… Continue reading EU-parlamentsvalget – undgå at støtte en corona-galning
LPBi14042 bicycle light
I’ve worked with electronics for a number of years now, but somehow I have not had occasion to do much reverse-engineering of existing circuits. But today I got the chance with a nice LPBi14042 bicycle front light that was acting up a bit. Here is the PCB: The PCB is nicely laid out and quite… Continue reading LPBi14042 bicycle light
Hacking a box of 240×320 displays with the ESP8266
For the last few days, I have been playing with some small displays we have lying around in Labitat. We have ninety-odd of them from an old donation, and I thought it would be cool to be able to use them for some fun projects. The displays are ET024002DMU with a built-in ST7787 controller. They… Continue reading Hacking a box of 240×320 displays with the ESP8266
FVWM and Java application window focus
I found the solution for a problem that has been annoying me for quite some time. I am using FVWM for a window manager. A few programs written in Java, most notably the Arduino IDE, will not accept keyboard focus. As soon as the window is given focus using normal window-manager commands, it immediately loses… Continue reading FVWM and Java application window focus
Improving replication with multiple storage engines
New MariaDB/MySQL storage engines such as MyRocks and TokuDB have renewed interest in using engines other than InnoDB. This is great, but also presents new challenges. In this article, I will describe work that I am currently finishing, and which addresses one such challenge. For example, the left bar in the figure shows what happens… Continue reading Improving replication with multiple storage engines
Understanding skew factors in Simplex/Improved Perlin Noise
[Here is a PDF version for readers whose browser does not understand MathML.] The Simplex Noise (or Improved Perlin Noise) algorithm uses a somewhat mysterious “skew factor” of 3–1 2 . I did not find any really satisfactory explanation for this factor in the descriptions of Simplex Noise that I read. But I managed to… Continue reading Understanding skew factors in Simplex/Improved Perlin Noise
Arduino to the max: 11x11x11 LED-cube
March 29 2014 is Arduino day, also in Labitat. This is a good opportunity to describe my LED-cube: This LED-cube pulls a number of tricks to get the most out of just a single normal Arduino Uno. A meager 16 MHz and 2048 bytes of RAM goes a long way with sufficient ingenuity and creativity.… Continue reading Arduino to the max: 11x11x11 LED-cube
No application changes needed: 10 times faster slave with MariaDB 10 parallel replication
Parallel replication is in MariaDB 10.0. I did some benchmarks on the code in 10.0.9. The results are quite good! Here is a graph that shows a 10-times improvement when enabling parallel replication: The graph shows the transaction per second as a function of number of slave worker threads, when the slave is executing events… Continue reading No application changes needed: 10 times faster slave with MariaDB 10 parallel replication