Optimization of relational databases without downtime on the example of the most loaded database in Badoo

3r3-31. Optimization of relational databases without downtime on the example of the most loaded database in Badoo 3r33333.  
Under highload conditions, the complexity of optimizing relational databases increases by an order of magnitude, since buying even more powerful hardware is expensive and it is no longer possible just to turn off the application at night for a long DB alter process and data migration. 3r33333.  
We recently told how we are optimized the PHP code of our application . Now came the turn of the article about how we completely changed the internal structure of the most loaded and important database in Badoo, without losing a single query. 3r33333.  
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The story of one experiment with Cython and C ++ vector

 3r33424. 3r3-31. 3r33333. One
warm r3r3255. on a cold winter evening, I wanted to warm up in the office and test the theory of one colleague that the C ++ vector could cope with the task faster than the CPython list. 3r33232.  3r33424. In the company we are developing products based on Django and it so happened that it was necessary to process one large array of dictionaries. A colleague suggested that the implementation in C ++ would be much faster, but I had the feeling that Guido and the community were probably a little steeper than us in C and probably already decided and avoided all the pitfalls...
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Saving data from a Linux partition

 3r3118. 3r3-31. Hello! 3r3105.  3r3118. I recently launched one toy in wine on my laptop with Kubuntu ???r3r3105.  3r3118. Everything was stuck and a file system error appeared on restart. 3r3105.  3r3118. There were important data on the laptop, so you need to get it somehow. 3r3105.  3r3118. Welcome under the cut! 3r3105.  3r3118.
3r3105.  3r3118. What comes first to mind? 3r3105.  3r3118. We have 2 ways to solve the problem:
 3r3118. 1. Try to repair the FS and get a working OS
 3r3118. 2. Copy the data and carry Linux
 3r3118. I chose option ? but I will tell about 1 too)
 3r3118. Restore ...
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 [Пятничное]ASCII graffiti on retro monitors and other surfaces

3r3-31. If a person who likes pixel art is old, then a person who understands ASCII aesthetics is a superstar! Of course, this is a joke, and the age is most likely irrelevant. My son, for example, likes to play ASCII games that I make. At least he says so.
However, in order to perceive some things, such as the composition of the three canvases in the picture below, you need to have experience interacting with a certain software and hardware.
 [Пятничное]ASCII graffiti on retro monitors and other surfaces
Under the cut you will see many ASCII tracks on monitors of ancient computers and terminals, as well as on other surfaces, for example, on a postage stamp...
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Apple patent for electric cars

Apple patent for electric cars “Before you think about solving future problems, learn to cope with today's for the shortest time and with greater efficiency.” (P. Drucker) 3-33114. 3r3117.  3r3125. 3r3117.  3r3125. charge current 3r3109. This is not an unimportant moment. 3r3117.  3r3125. 3r3117.  3r3125. Of course, this principle of charge will be useful for an ordinary electric car, but for a start it is better to use it on less maneuverable vehicles. For example, on trucks at
3r3117.  3r3125. 3r3117.  3r3125.
The use of the principle of energy transfer in motion can be called only on motor vehicles. 3r3117.  3r3125...
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Nuclear power before the appearance of nuclear power plants

3r3-31. 67 years ago, on December 2? 195? the experimental fast EBR-1 reactor became one of the first nuclear power sources. The photo shows ??? W bulbs that he “lit” that day. Before the launch of the first-ever nuclear power plant in Obninsk, about 3 years remained. 3r3105.  
By the memorable date, a small story about the appearance of this reactor, a photo of what is with it now, and an explanation of why it is not considered a full-fledged nuclear power plant. 3r3105.  
Nuclear power before the appearance of nuclear power plants 3r3105.  
The first electricity from the EBR-1 reactor in 1951. Photo: ...
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Biohacker Joshua Zeiner's public letter

3r3-31. Biohacker Joshua Zeiner's public letter  
I always come back to the question: “Would you go to prison to save someone's life?” As you can see, I receive a lot of messages from people who seek medical help. I try to convince myself that I cannot help them, but the reality is that the system broke us. We must be ready to do everything to save lives. We must treat everyone as a loved one. Instead, people are left to die and suffer, because we, as a society, are too afraid to take responsibility for the riskiest or most modern treatment methods.
I remember the first time someone emailed me. I was shocked for several months, thinking ...
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Compiling and running C # and Blazor inside

Compiling and running C # and Blazor insidebrowser. 3r33333. 3r3-31.Introduction 3r33333. 3r33333. 3r33333.If you are a web developer and are developing for a browser, then you are definitely familiar with JS, which can be executed inside a browser. There is an opinion that JS is not very suitable for complex calculations and algorithms. And although in recent years JS has made a big breakthrough in performance and breadth of use, many programmers continue to dream of launching a system language inside the browser. In the near future, the game may change thanks to WebAssembly. 3r33333.Microsoft is not standing still and is actively trying to port ...
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New LED lamps Diall

 3r33150. 3r3-31. I recently tested 46 Diall lamps and wrote a review ( Habr.com/company/lamptest/blog/427459 ), But almost immediately after this, the range of lamps of this brand completely changed. I bought 19 new lamps and tested them.
 3r33150. 3r3118. New LED lamps Diall  3r33150.
 3r33150. Uprtek MK350D . The minimum operating voltage at which the luminous flux decreased by no more than 5% of the nominal, was measured using an instrument. Lamptest-1 3r3134. , stabilizer
Calm Instab 500
and LATRA Suntek TDGC2-0.5. Before measurements ...
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Habro suicide. Why 1C programmers will save the world

Hope for change faded away. Qualitative changes can only be carried out by the head of the company, or very expensive consultants. The changes will take years - with our blockheads on the ground. No one will understand the essence of transformations, so no one can develop them. Instead of one inert system, we get another - more efficient, but also inert. Any relatively large change in market conditions will require a quick restructuring of the company, but we do not have people who are ready to understand and implement these changes.
Or is there? Maybe look around? Who do we have besides the ...
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