Die wunderbare Welt von Isotopp

MySQL: The Million Challenge

Kristian Köhntopp - September 10, 2021
A long-standing idea that I have is to test the servers limits: How does it fail and break if there are very many of a thing? Previously that was too easy, because many structures were constructed in a way that it was obvious they would not scale. But with MySQL 8 many things were overhauled, so let’s see what we can make many of and see how the server fares.

MySQL: The table '../tmp/#sql…' is full

Kristian Köhntopp - September 9, 2021
We observe a large number of messages of the kind The table '../tmp/#sql…' is full Before MySQL 8 In older Versions of MySQL, implied temporary tables are being created whenever your EXPLAIN contained the phrase using temporary. In this case, MySQL would create an in-memory temporary table to materialize an intermediate query result, and then continue to process the data from there. If that temporary table was larger than some configurable limit, the temporary table would instead be converted to a MyISAM table on disk, streamed out, and then work would continue with this.

MySQL: Two kinds of compression

Kristian Köhntopp - September 9, 2021
I never had much reason to use table compression, so I largely ignored the topic in MySQL. I knew that MySQL had table compression since 5.1, but I also knew the implementation was horribly complicated and double stored all data. There is also page compression, a feature introduced with 5.7, which replaces table compression and works much better. Table Compression Table Compression is available in MySQL 5.1 and newer. It is used by setting an InnoDB table up with ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=8 or similar, for even smaller key block sizes.

Computer science

Kristian Köhntopp - September 7, 2021
Lilith Wittmann asked on Twitter: Why do we have so much dangerous software in Germany? Because we don’t have the competency anywhere (administration, enterprise or science) to understand the complexity of software. My take was : Computer science is easy. It is the science of Zeroes and Ones, and it does not get any more complicated anywhere. Computer science piles abstractions on top of each other, though, 30 layers deep and with non-linear interactions.

Fertig gelesen: AI Superpowers

Kristian Köhntopp - September 5, 2021
This 2018 book in some aspects is already outdated: Silicon Valley Techbro Kai-Fu Lee describes what AI is and what he thinks it will do to our future, the nature of work and the job market. But since then, the worlds view on what AI can and cannot do, what the problems to solve really are and a lot of other things have changed. AI Superpowers:China, Silicon Valley, and the New World Order , Kai-Fu Lee

Fertig gelesen: Old Man's War

Kristian Köhntopp - September 5, 2021
“Old Man’s War ” is the first “large” works by John Scalzi, Old Man’s War , John Scalzi The plot premise is weird, but simple: Humanity has taken to the stars, but with private enterprise. Basically all advanced space technology is controlled by the Colonial Union. Life on earth on the other hand goes on almost as before. John Perry enlists to serve in the Colonial Defense Force at the age of 75, to protect humanity, but mostly to have the CU fight the effects of him aging with some unspecified Scifi tech.

Fertig gelesen: These Savage Shores

Kristian Köhntopp - September 5, 2021
Ram V is a writer, sometimes for comics. Together with artist Sumit Kumar he wrote a simple story: English Vampires vs. Indian Rakshasa. These Savage Shores , Ram V & Sumit Kumar The 1760’ies. An english vampire puts his peers at risk by not having his desires under control, and is exiled to Calicut, India. He soon finds out that even older and fiercer beings rule the night: Rakshasa, the Vampire equivalent of Indian Myth.

Fertig gelesen: This Is How You Lose The Time War

Kristian Köhntopp - September 5, 2021
Max Gladstone and Amal El-Mohtar co-authored This Is How You Lose The Time-War , not exactly a Science Fiction novel. This Is How You Lose The Time War , Amal El-Mohtar and Max Gladstone Red and Blue are representatives, spies and saboteurs of two nearly all-powerful, warring factions. They travel through time to manipulate events at critical points in history in favor of their respective factions. They are leaving each other messages, they taunt each other, and gradually earn mutual respect.

Fertig gelesen: Typeset in the Future

Kristian Köhntopp - September 5, 2021
Dave Addey ran a Tumblr once, titled “Typeset in the Future”, in which he dissected the typography of Science Fiction films. This has been turned into the eponymous book. Typeset in the Future , Dave Addey In 2013, Addey nerded out over the fonts in a Science Fiction movie and discovered it was an Eurostile variant (“Eurostile Extended Bold”). He started a Tumblr about this, and in great detail went through a number of movies, and about every sign, letter and font used in there.

Fertig gelesen: UNIX: A History and a Memoir

Kristian Köhntopp - September 5, 2021
The memoir of Brian Kernighan, and the story of how UNIX came to be and what working at Bell Labs was like at that time: UNIX: A History and a Memoir is required reading for anyone who wants to know where Unix concepts came from and what ideas were behind its inception. "UNIX: A History and a Memoir ", Brian Kernighan Kernighan takes us through the history and the setting of Bell Labs, why it existed and what it did.


Kristian Köhntopp - August 18, 2021
I had reason to look into the UNIX Eschaton, the time when the signed 32 bit counter of seconds since Midnight, 1970-01-01 UTC overflows. Going to Wikipedia , I learned we will die two years earlier, because in 2036-02-07, 06:28:16 UTC NTP will kill us all: At 06:28:16 UTC on Thursday, 7 February 2036, Network Time Protocol will loop over to the next epoch, as the 32-bit time stamp value used in NTP (unsigned, but based on 1 January 1900) will overflow.

Fertig gelesen: 88 Names

Kristian Köhntopp - August 3, 2021
It began with a tweet by Sebastian Bergmann , which made me buy “88 names ” by Matt Ruff. The book is a tour of massive multiplayer online role playing games for people who do not play, and also a discussion of identity on the Internet. John Chu has a small sherpa company, an outfit that helps causal players who have the coin to experience hard content in MMORPGs in an easy and successful way without investing too much time into the game.

Fertig gelesen: A Kim Jong-Il Production

Kristian Köhntopp - August 3, 2021
Paul Fischer writes “A Kim Jong-Il Production ”, a documentary the 1978 abduction of the famous South Korean actress Madam Choi, and her ex-husband, the filmmaker Shin Sang-Ok. Before becoming the leader of North Korea, Kim Jong-Il headed the Ministry for Propaganda. Dissatisfied with the talent available, he had the famous actress Choi Eun-Hee kidnammed. When her ex-husband started to investigate, he had him kidnapped in Hong Kong and transported to North Korea by ship.

Fertig gelesen: Mara und der Feuerbringer

Kristian Köhntopp - August 3, 2021
Tommmy Krappweis ist nicht nur der Schöpfer von “Bernd, das Brot”, sondern auch ein Musiker, Stuntman, Filmemacher und Autor diverser Bücher. In der Trilogie um “Mara und der Feuerbringer” nimmt er uns mit in die Geschichten um die 14-jährige Münchnerin Mara Lorbeer in der Welt der nordischen Sagen. "Mara und der Feuerbringer , Band 1", Tommy Krappweis Mara Lorbeer ist 14, Scheidungskind und lebt bei ihrer esoterisch angehauchten Mutter in München.

Fertig gelesen: The Merchant Princes Omnibus

Kristian Köhntopp - July 28, 2021
Charles Stross “The Merchant Princes ” series of six books is another “Sliders ” type of story, with the usual Stross-like twist. The story follows Miriam Beckstein, a woman who thinks she is a tech journalist. Miriam falls off a chair while looking at a strange pattern, and finds herself in a medival parallel earth. "The Merchant Princes Omnibus ", Charles Stross In the course of the story, Miriam learns that she is actually from this parallel earth, and really is the Countess Helge Thorold-Hjorth in the kingdom of Gruinmarkt, which sits in the place of her world lines Boston.

Fertig gelesen: Outland

Kristian Köhntopp - July 23, 2021
“Outland ” is the first book by Dennis E. Taylor, preceding the Bobiverse and also “The Singularity Trap”. It is a “Sliders ” storyline, much like Pratchett’s and Baxter’s “Long Earth” , in which our heroes discover a parallel dimension with a seemingly uninhabited earth, and then need to colonize it. Outland , Dennis E. Taylor Dennis E. Taylor is a computer programmer writing Scifi, and had problems finding a publisher for his debut novel, “Outland”, in 2015, so he self-published.

MySQL: A job queue in Python

Kristian Köhntopp - July 13, 2021
Somebody needed a job queue in Python: Multiple writers insert into it in random order, and the jobs are written into the MySQL table jobs. From the jobs table, multiple consumers claim jobs in batches of n or smaller (n=100), and process them. After processing, the consumers delete the jobs. We need concurrent job generation and consumption, with proper and efficient locking. The full source for this example can be seen in mysql-dev-examples in mysql-claim-jobs.

Fertig gelesen: Montecrypto

Kristian Köhntopp - June 5, 2021
Wir hatten hier in den Reviews schon eine ganze Menge Tom Hillenbrand: Drachenväter , Drohnenland , und Die Drohnen des Monsieur Leclerq . Das aktuelle Buch von Tom Hillenbrand ist Montecrypto , das sich mit dem Hype um Cryptocurrencies beschäftigt und eine Art “Der Graf von Monte Cristo”-Geschichte erzählt. Montecrypto , von Tom Hillenbrand Gregory Hollister, ein reicher Investor, ist verstorben. Angeblich hat er noch eine große Menge Geld, und dieses ist in Bitcoin angelegt und irgendwo versteckt.

Fertig gelesen: The Black Count

Kristian Köhntopp - June 5, 2021
Another Monte-Cristo-themed book, Tom Reiss’ The Black Count nicely complements the german sci-fi novel Montecrypto by Tom Hillenbrand. It is a biography of the father of the French write Alexandere Dumas, Thomas-Alexandre Dumas Davy de la Pailleterie. "The Black Count ", by Tom Reiss. Alexandre Dumas, the author of “The Three Musketeers”, “The Count of Monte Cristo” and many other books, is one of the most read French authors. He had it easy coming up with stories, because his father had one of the most unusual and wildest lives imaginable.

NVME is not a hard disk

Kristian Köhntopp - May 25, 2021
So somebody tweeted about the Seagate Mach.2 , a harddisk with two independent heads “combs”, and I commented in german : “It’s two drives in one chassis, even shown as two drives. And it still is rotating rust, so slow with seeks. Linear IO will be fine.” That quickly devolved in a discussion of RAID-0 on a single disk drive : “RAID-0 on a single physical drive. Yeah, you can do that if you do not need your data.