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31st May 2019

10:08am: This blog
I'm writing the blog in English because I type twice as fast this way than in Russian (yes I am improving...), and 90% of my friends and friends can read English any way. I answer comments in the same language they are posted.

I am trying not to post anything related to my employer, but if I do so, this expresses only my own views and does not represent an official position of my employer.

When I post about some technical topic which seems non trivial and is related to my employer's product, don't expect it to be inside information. If I post about it, it means that this info is already public. Usually I do not post any personal information or anything that is related to my family.

All photos are mine, and I allow anyone to copy, change, do anything you please with them. I don't post "friends only".

Useful tags are: software , idea , Deutschland, readlog, freediving and trip report

13th January 2017

4:39pm: Lufthansa lifehack
I am saving my work travel budget like it is my own money ;) At Lufthansa, ticket Shannon->LHR->Munich was much more expensive than Shannon->LHR+LHR->Munich. But in the later case connection failure is my risk.

So I bought Shannon->LHR from another airline, and LHR->Munich from Lufthansa (the later costed ~100 euros), with connection time 8+ hours. The risk did not manifest, should I wait for 8 hours in the airport, or go to London for a short stroll? No, I asked a lady at Lufthansa transfer counter to get me on a next flight (whiсh I did not book because of the risk to miss it) for free, and just got a new boarding pass.

3rd January 2017

12:31pm: German history and political system test
Got an exam result: me 31/33, Yulia 33/33. I was making fun that she does not know all Bundeskanzler of 20th century and capitals of every Bundesland, but she scored better than me in the end.

The weird part was a history of east Germany. According to the test questions, here is what happened:
DDR was formed in 1949, then there was an uprising in 1953, Berlin wall was built in 1961, then it was destroyed in 1989, then in 1990 East Germany was dismissed. Yeah, also there was STASI there, and a national emblem had a hammer, rye and a compass on it.

2nd January 2017

3:08pm: Bayesian healthcare in Germany
My experiences with German healthcare were positive, but there is one minor thing that still bothers me. (Nothing is perfect.)

Say we have a benign disease X that lasts 7 days (I didn't mean flue, but math could be similar there too), and in 10% of the cases it results in a complication Y that lasts 14 days. Not treating X costs 0, treating X case costs N, and treating Y case costs 3*N. Bingo, thinks an insurance company: 10%*3*N < N, and makes not treating X a default. That is all statistics, in reality it is much more complex but you get the idea.

For an individual, math is different: treating X means you recover in 5 days, not 7, and risk of Y goes down from 10% to 0.1%. So you gain ~3.4 days of productive life if you treat X.

What are the options in Germany? You can get private insurance, in that case they treat X. You can try treating X yourself, but you'll need to somehow get a prescription drug (thanks Aeroflot :). Also, there is another option, a strange one but it certainly works: you go to a doctor that does not know you, pretend that you are a tourist ready to pay cash, pay ~100 euros and get a treatment. This works if you have a non-German passport. I wonder how/if a German can use this loophole?

1st January 2017

11:09am: Jacob speaks, new year
Jacob (2.5 y.o) got a pack of playing cards:
"Это король, это королева[дама], это принц[валет], а это - ученый младенец [джокер]".
Откуда он взял это сочетание - "ученый младенец?"

28th December 2016

1:51pm: Empty office, performance bugs
On Friday I was given an urgent task: I'll have to find a solution or at least a root cause of a performance problem reported by a customer, by the end of 2016.

The issue to investigate sounded extremely familiar: a micro-benchmark runs for 100us on micro-arch A and B, and for 100-200us on micro-arch C, everything else being equal. We want a design on C, performance between A, B and C are similar, what brings the difference?

In my Christmas/New Year case I was lucky and it was merely an SMI.

The very first thing to check is always to read MSR 0x34 that counts SMIs before and after u-benchmark. It is not the most common source of such issues, but easiest to check, and not difficult to fix, if you have 100% control over the platform.

22nd December 2016

9:32pm: My B1 results
Listening - 19/20
Reading - 25/25
Writing - 17/20
Speaking - 97/100
I expected speaking result to be around 75/100 which could be either fail or pass. So I am surprised that German I speak (turning everything to nominative, present tense, neutral gender) was scored that high.

p.s. I never ever studied German, just keep absorbing it from the air :)

21st December 2016

5:04pm: Russia's advances in XIX and XXI centuries

Nuff said.
10:03am: US consulate, again
Livehack to use a clearance received 11 months ago did not work. My file will be sent to US for security check again. This time a consulate officer was even more inquisitive about essence of my work, and he seemed to understand subtle details.

Also it was funny that a queue machine was broken, so they arranged two live queues to interview windows. To mark these queues, they built a device from a ruler, a lot of sticky tape, piece of cupboard and A4 print. And this construction had an inventory tag on it :) Alas, one cannot make pictures in a US consulate.

9th December 2016

6:02pm: Dybr
Low light of the week -

Mushrooms I picked at our office and pickled are all gone.
Highlight - I took B1 test, but have to wait for a month for the outcome. DTZ B1 is much easier than Goethe Institut B1, but DTZ has not entirely consistent test process.

1st December 2016

9:17pm: Jacob speaks
At 2 years 5 months:
- Я вырасту, пойду в школу. Потом совсем вырасту, стану космонавтом. Наденусь космонавтом, надену шлем, полечу на ракете. Прилечу на луну.
- Зачем на луну?
- В шлеме, на ракете, на луну!

I did not expect modern kids to dream of being an astronaut. Maybe this is because of Musk?

27th November 2016

6:38pm: No more wired
From time to time I buy a UK edition of Wired magazine. It is so much like Компьютерра in late 90s-early 2000th!

Not anymore. Now there is a German version available, so all shops here stopped selling a UK version. Same happened with Maker magazine few months ago..

21st November 2016

6:09pm: My job hunt stats for 17 years in the field
17 years ago I started my first full time s/w engineering job, and now I'd like to count my experience with software developer job interviews, from the interviewee part of the table.

I was interviewed 7 times. I passed 6 interviews, failed a google interview, and accepted 5 job offers.

During this time, I also applied for about 30 jobs (all very close matches, some referred through ex-colleagues), and I got 0 interviews from these applications... That includes 0 interviews out of 3 applications in 2016.

All 7 interviews I attended so far were results of networking. I guess my CV is really bad :)

12th November 2016

6:18pm: German B1 test
I just took an 8 hours preparatory course for B1 exam, which included 3 test runs of an actual exam. I got very consistent score each time: 25/25 for reading (takes me 15 minutes out of 45), 18/20 for listening, 15/20 for writing, and 70/100 for speaking. To pass, I need 33/45 for listening and reading combined, 75 for speaking, and for writing I can just write an essay that consists of "F%^#k you!", get 0/20 and still pass.

Of course it is not fair. My current level of German is certainly A2, and the only reason I get nearly highest score on reading+listening is because reading+listening is merely an IQ test in disguise. So to get B1 you need to have either A2+140IQ, B1 and 110IQ, B2 and 100IQ, or C2 and 80IQ :) That simple!

10th November 2016

3:51pm: Winter coming
Every autumn, I collect these nuts on my way to work.

There are plenty of trees on my way through a park, and I never seen anybody eating these tasty nuts (except squirrels and pigeons.) Before I moved to Germany, I never seen these.
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Alas, winter is coming and I find less nuts now.

2nd November 2016

10:14am: Best views of Istanbul
I use Istanbul frequently as a convenient hub (and Turkish airlines serve great food in economy), but usually Istanbul airport approach is not very interesting.
But once recently I got a very nice view all the way to the airport.

The plane went at a low altitude across black see, the strait and Hagia Sophia. Unfortunately I did not get my camera back then. I wonder if it is possible to check if my next flight will use same approach in advance..

29th October 2016

9:35am: European Union
Interesting article. Nothing really new, but this passage is very interesting: "Deutschland hat zugesagt, in Litauen die Rolle der Führungsnation zu übernehmen. In Polen tun dies die USA, in Lettland die Kanadier und in Estland die Briten."

Reading Die Welt sometimes is more entertaining than Russia Today ;)

19th October 2016

11:52am: Intel Processor Trace on Joule
I just checked Andi Kleen's github repos for IPT, and it works perfectly on Joule. Unlike most experimental code, this one works out of the box. What I did not expect, I started full trace on stream, and stream results did not change!

It means that on Apollo Lake Atom platform, IPT is 0% intrusive - a very good sign!

P.S. Processor trace is the future of low level performance profiling.

11th October 2016

10:04pm: Trip report: Torino
I am travelling to customers as usual, but since Jacob was born I no longer have extra time to explore, and trying to schedule trips to the minimum. This time I had slightly more time than usual and spent couple of hours walking around Torino.

I like a walkable city center very much. It is huge (bigger than in Milano and not as crowded as in Rome) but nice and comfortable. All these small shops selling different types of weird stuff. Like one in front of my hotel sells only tableware for pets.

And food was good too:
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10th October 2016

2:12pm: 3d scanning and VR
This weekend I tried to get Yulia into VR. So I took a Realsense camera, and tried scanning her with 3D systems Sense. I failed, it almost worked but stalled so often! Then I installed ItSeez3D scanner. It was much better, but still you need a model to stand still for 2 minutes, and I guess it only works with Lenin mausoleum guards.

Still I got an obj; and tried composing a simple WebVR page. It worked, but it was awkward. Then I uploaded to sketchfab, and finally I was walking around virtual Yulia wearing my Oculus Rift. Model was not perfect but better than nothing. Verdict: it is not consumer ready yet, but very close. Once everyone will have a VR headset (most likely google style), ppl will routinely scan their 3D models and special moments in VR format.

5th October 2016

12:12pm: Russian high schools rating 2016
I read a Russian high school rating, they just published a fresh one for 2016.

My alma mater this time is #55. (Slightly dropped from #51 in 2015).

Then I tried looking for the school #40, Nizhny Novgorod, but did not find it anywhere in the list. I remember that in late 90s, there were more smarter kids graduating #40 than my school, so my first thought was "Sic transit gloria mundi".

But then I looked at the rating formula, and it is clear how my school could had surpassed #40. One of the key metrics is the enrollments rate to top 20 Russian Universities. Most of these top20 are in Moscow and St. Petersburg, except for Ekatirinburg, Tomsk, Novosibirsk and Kazan. But University of Nizhny Novgorod did not make it to top20. So all folks who graduate #40 and make it to a local University do not improve the score for #40.

There is obviously no top University in Cheboksary, so my fellow alumnus typically go to Moscow, St. Petersburg and Kazan once they graduate the school.

4th October 2016

5:30pm: Good SPDK intro
SPDK is DPDK for storage. My team mate just published a good intro article. SPDK is so DPDK, that it does not just use the same approach we use to process 100+Gb/sec of traffic on few cores, but needs DPDK for almost everything .. except storage ;)

2nd October 2016

2:29pm: On Joule power consumption
I just made my first measurement.

Joule, currently the most powerful wearable computer, works for nine hours from 2.4Ah 3C LiPo battery; wifi was on and streaming, with moderate CPU load.

I guess I'd need to buy 3.9Ah for twelve hours. Also I hope a less sophisticated carrier board, when available, would help.

1st October 2016

10:01am: My preccccious

I am no longer working on this type of stuff, but still like it a lot so got one just to play at home. (Everything is great in this board except the price)

30th September 2016

1:39pm: My brother's work
I liked this one:

And it is not blocked in Germany by youtube as usual.
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