Logs, shells, caches and other strange words we use daily

Uh we will not do anything complicated here. It's a very last session for today. You should be already like filled up with a ton of complicated details about migrating billiards of big ins to ints and what actually other way ints to big ins and stuff like that. So this one will be really relaxing. We will just go a little bit retrospectively back in time and Try to kind of maybe fill up a bit of the gaps in knowledge as I did during the preparation for this talk. Where Do words which we use in our professional life come from. If you will read abstract for this talk, you will see that I was a bit ambitious when I've listed quite many of them. Uh during the preparation it turned out that it's a little bit too much. Uh

one uh cannot really make a like a good storyline out of those pretty independent words. So that that means it gets boring pretty fast. So I've reduced it a bit, so hopefully it will work. A few words about myself. My name is Slava. I come originally from Ukraine. Lived for the last half part of my life, about 20 years in Germany. Yeah, and as majority of people here, I basically code for money. So I'm freelance developer. Sometimes for food, sometimes for money, depending how good is the project actually. Nothing special here. I uh would like to keep the let's say technical details uh out of our way. All the background pictures which I've used here, if not mentioned, are coming from this website mentioned here.

And in highly unlikely chance that you will visit Dortmund, and probably the only reason for visiting Dortmund is uh for Borussia Dortmund's game, so for football. If you will be around, please send me an email. I would be really happy to go with you for a beer or a coffee. So those kind of things we get out of the way. I've already wasted two of my minutes, so let's start with the words Which we would like to talk today about. So first one is LOX. LOX is something this the original idea for this presentation. I was starting to think like. What does it mean? I'm not a native speaker, as I presume majority of the people in this whole. I have no idea. What does it mean, lock? I had to open the dictionary and check.

And um yeah, so um if like doing login is pretty easy in our case. In in Python you just throw import a module, do some things, and out of that you get uh such statements in this case it's just some output of um of Django requests or server locks. Nothing fancy here. You see that the locks uh have certain structure, they have timestamps, certain um uh uh information about the level and the details of the lock statement itself. If you have a fancy tool like Datadog or Elasticsearch or Elkstack, You can use this kind of the information to uh filter the locks. So I think you're all set with the locks, right? It's uh uh one of the pillars of modern observability.

But where does the word come from? Um if you will check the dictionary, but log means actually the piece of wood. And a friend of mine Thought that you know those kind of things they look like a pieces of wood, so that's why they are called locks. No, it's a bullshit. They are not But they are really much related because the origin of this word comes from the Nordics from the uh sea navigation. At some point, especially at the age of uh discoveries, uh these uh the the captains uh started to to to kind of keep track on what is happening, uh where they are, and try to kind of

um have some kind of the of the journal of their journey through the through the seas. And they started with the very first essential thing is their speed. So how do you measure the speed? At that time there was no GPS, no smartphones. It was terrible word probably. So you had this wonderful device. So it's basically the lock. the piece of wood, the rope, and the rope had some uh marks on it. Someone just when you are on the on the on the ship throws the this lock Uh it rotates because the ship moves and someone nearby has the some some some device like a watch which measures the time. And he counts how many marks have passed by, gives this information to the captain. Captain with a lot of high-level mathematics

computes it into the speed, writes it down into the journal, and here we are. That's the first logbook. So something where the speed of the shift was actually written down. Um everyone liked this idea. Um and those log starts log books started to evolve. Um if in the beginning there was just the speed of the ship they started to give Much more information about like could the weather conditions, different events, what happened. So something like a diary of the ship Um you see there they were some of them were extremely nicely illustrated with the pictures and with some fishes they found. So it was even even I would say the piece of art uh or the scrape book as they call it uh

these days but practical one and That was let's say sixteenth, seventeenth century. This idea of having the detailed timeline of certain events was pretty much Helpful inside of the of the navigation and gautics, and as technology progressed, this kind of the ideas were transferred into the other. forms of engineering and transport aviation and here for example you see that that's kind of the log entries for the steam locomotive. looks pretty much somewhere in the same direction. But the key idea is that from uh sea and now

navigation it's somehow transferred into other branches of uh engineering and finally Finally. Somewhere in the middle of 20th century, um programmers started to use logs Very important. At that time there were no programmers, like right, it's the middle of the 20th century. People who became programmers, they were not programmers, they were just like mechanical engineers, mathematicians. um chemical engineers, people coming from military, a lot by the way. So those people have those different backgrounds and Because in their backgrounds the whole idea of the lock was already pretty much established, they took it over into the world of computers and used the

uh the same process in order to describe um what is happening with this huge machine which was called a computer back in the day. Interesting, you see locks were handwritten back in the day. So still middle of 20th century, computers, everything, digitalization, blah blah blah. Like in Germany these days, but A little bit better. Um but um yeah, handwritten logs is something I would say it looks unusual to me. least. And only uh from there on we landed to what we kind of get used to have uh in the modern uh in the modern world. You see they uh haven't changed that much since the world s since the time of the first Unix

distributions. Um so something what has chronological record keeping Like in back in the times of maritime logbooks, it has their incremental data structure, so everything is just a pendant, and um uh that is something which you can use for uh Uh trying to understand what's happening with your system. Well, if you will probably look into all that from the modern point of view, you would call it maybe more of the event stream or like uh eventing systems, but. In the end of the day, that was locks. So what is most important with that? When next time you will writing some kind of the log statement, don't forget that you are throwing a log.

Very important. Because that's how it goes. That's all for the word lock. Let's move into the next one. Cash. I don't know how you are, but when you just read on the on the name of this word or how it's written, you immediately think it's probably French. Because E in the end, S H probably French. Looks like French. It is French. I don't know. I'm not French. I don't know how to read it. If someone knows how one should read this, uh the origin of this word cash is this Cashi or Cashi? I'm not sure. Cash, Cash. Cash, Cashie. Yeah, so it was somehow just pulled off and uh being used as the word

cash and in French it means too hide. So it might this word was basically imported from French into English in the 18th century. uh basically for the military and for the exploration and meant something you know you put um kind of some food or some ammunition somewhere well hidden so that the next uh sor or future future yourself or someone who will follow your steps for the same um expedition will just use this thing uh in order to kind of survive or make their mission more acceptable, more successful. But we are all far away from military, I guess, or majority of us

So actually the best example of what this caching is what squirrels doing. Because you see, a single squirrel can bury up to three three thousand nuts in a season in the process known as caching. So they do it pretty regularly and independently by the way out of computer science. And because Squirrels are such a let's say live uh and vivid example of uh of caching. It turned out that they were used um a lot in the times when or a lot uh during the teaching of different methods of caching uh especially in eighties and nineties so they became a symbol of um uh of a of a cache. Um I haven't found any uh photos unfortunately

of any textbooks or lecture notes, but if someone will find it would be very nice to see. Yeah, by the way, the One of the most interesting question, which scientists are still not sure about that: if this nice little squirrel hides 3,000 nuts in a season. Does it remember where did it put it or not? Very good question. No one knows. But now scientists Tends to actually answer with higher probability than in fact yes it remembers and knows all the nuts it uh puts into the cache. So cache appeared in 60s or 70s, mostly as

majority of the things mentioned here in IBM research papers. Um nothing really interesting about it. It was something where you can, you know, access access data fast. And without much of the of the fuss. Important was that engineers also borrowed this term because the cache, at least in the initial systems, was the hardware cache. It was hidden from the user or from programmer back in the day. So that's why it was something which is what happening let's say outside of your control. Of course, as the time evolved, we've got a ton of different caches. Django

itself um has a number of different levels of caching, but of course we have CDNs, we have Redis, we have everything we have different levels of caching in computers. So it's one of the most important things which makes our systems faster. And finally, the maybe the the most Ironic and funny fact that in modern French French tech world, uh it borrows word cash in its current English form from English, and actually uses the English form for um for naming this concept of cash. Quite interesting linguistic linguistic twist, I would say. So uh let's try another one. We'll see how how many can we manage in the next 10 minutes.

The the very very evil word. Demon. We have experts here who uh who know what. uh how how one should read the the old Greek. So daemon? What was that? Demon. That's the origin of this word. It's actually nothing really bad. It was somehow demon demo d this d demonization or let's say a bit of uh bad reputation the demons got uh during the Christianity, but technically they were not evil, they were just like, you know, some kind of the supernatural beings. Nothing Nothing really bad about them. And how it relates to relates to our demons. Actually, strangely enough, James Clerk Maxwell, one of the

most prominent scientists uh of uh 19th century. Uh he did a lot of different things and one of them was A thing called uh Maxwell's demon. It's some kind of the thought experiment I will show on the next slide, uh which um just like som fin så hypothetical konstruction which he wanted to present in order to uh då some kind of the thinking about the loss of thermodynamics. Most importantly, it was some kind of the entity or creature which does something without expanding any kind of the work. So free worker. You see already starts. Something uh something looking what we're used to. Maxwell was a very religious person, so of course he would never ever

call uh this entity a demon, but Lord Kelvin, who was apparently not that religious person called this uh given the name of this concept as a Maxwell's demon. So that's a small illustration of this nice demon who just you know opens the gate for different molecules and just lets some of them in or out. The most importantly it does it in the background without any control and without expanding any kind of the work. And that 's kind of the demon was exactly the inspiration for introducing the word of the demon. in 1963 in computer science. So that was a group of um MIT project Mac including Fernando Corbi Corbato, one of the Turing um

finalists or the persons who got the Turing Award in 1990. And he was including his group working on building one of the MIT computer projects. And here is the quote: we fancifully begin to use the word demon to describe background processes that work tirelessly to perform system chores. Chores. Yeah. So uh the But a twist, right? So something which is coming from the thermodynamics and Maxwell somehow landed in the project related to the computer science and finally landed to what we use each day on our systems. as a background processes. Um and yeah.

Um not everyone just like maybe liked the idea of Of uh being referenced to something from Maxwell, or maybe it was too much. So as many times we and software engineers and system administrators are doing, um it was rationalized via so via via so-called backronym as a disk and execution monitor. Has nothing to do with the original concept, but nevertheless uh you can find this kind of the um explanation of the word demon in uh in the wild. Uh there will be another example where a similar thing happened with another word. So, how much time do I have left?

I just need to pick up which one's the most spicy ones. Okay, let's let's do maybe two short ones. The bit, bit, you know, the the the smallest piece of information, the bit. It's pretty simple, it's it's just a contraction of two-word b binary digit or binary information digit So the father of uh modern information theory, uh Claude Shannon, introduced uh or used the word bit in his In his paper, which is highly cited, I would say, Mathematical Theory of Communication. You see, it was also published in the middle of the 20th century. And

basically they needed something what could take the just two values, zero and one. So this kind of thing didn't exist. So they invented this a binary information digit or simply bit. But um Shannon uh uh didn't invent this word by himself He attributed the origin of this term to John Tukey. Probably hopefully I've read it correctly. who actually uh at night uh also at 1947 somewhere in the communication in the bell lapsed used this word bits as a binary information digit What is interesting, uh I'm not sure if you ever heard about um this

person. I never. He did a lot of work and mathematics, which I'm pretty far away, so I don't know. Except maybe one. He is also like one of the fathers of fast Fourier transformation, which which is a cornerstone of all modern image processing. But for us, the most important that Uh besides many things, Professor Tucki coined another term which was foundational for our industry. In fact, this word is software. So he was the guy who uh uh who introduced the concept or the the coin the word software in um our lives. So all industry, thank you. That's Pretty pretty good. Um byte, bigger or smaller brother

of uh of the bit. uh just the collection of some bits. Um here story is not really somehow spectacular. They just needed to have um uh uh uh an ability to to represent a character uh uh via some bits and this number of bits they call the byte. The then the the term byte uh was introduced by Werner Buchholz uh in um uh yeah I forgot it's somewhere in 1961 yes I uh yeah it's not on the slide in nineteen sixty one um just to to to kind of like sound very similar to bit but different and easy to pronounceable

so you know the bit was already there on the market and like for t for more than ten years and they just uh introduced the word byte to symbolize the the number of the bits. Uh what is interesting that it was not really eight bits. That time it can be six bits, seven bits, even variable number of bits, and only like 10 or 20 years later it was standardized into eight bits. Yeah, so that's the story. Um yeah, that's a very good one. The word ping. Bing. You know, ping Also comes from uh the naval systems or from the from the sonars. So sonor is uh

written that It's a shirt for sound navigation and ranging. So system of the navigation. So what is ping? Ping was the shirt burst of sound, which uh was used for like throwing the sound inside of the water uh and waiting until uh the sound will be reflected from some kind of the obstacles on its way, measuring how long it took to come back, and based on that you can try to build the mathematical model and tell how the things look around you based on the distance. I think majority of you seen those nice American movies where you know the the crew of the submarine uh like this psh bing

ping and everyone is sweating and there should be no sound and then at some point someone sneezes and yeah that's the end of the world they discover it and everyone is dead so terrible what should Um so that that that was the ping. And the word ping uh sounds um or was s exactly selected that it sounds like this uh this burst of sound which was thrown by the by by by the by by by those audio generation devices because it was pretty high frequency, a sharp sound, and it sounded like day this way, and it was called ping. And this guy who I also quote here from his original website, unfortunately, that's one of the examples why I decided to keep the reference to the website

because uh Mike must passed away a long time ago but uh his original writing about the ping as utility still lives on this under this website under this web address and one can actually uh read uh his own words about this thing. That was just a hack which he written uh in nineteen eighty three in order to check some connectivity. And I name it after the sound that the sonar makes, inspired by the whole principle of echolocation. So yeah, that's how the echolocation and once more the the the navigation and the um the terminology from The Nautics and maritime sciences came into software engineering.

Pretty unexpected, I would say. But yeah, that's how it is. Thank you, Mr. Mousse. Uh we have a few more minutes. Ah yeah, maybe just a short one. And as usually, as you've seen before with the demon, same happened actually with pink. People like didn't like the sonars apparently I don't know why they're nice or maybe they were scared of those American movies. But packet internet groper if it helps I don't know But yeah, that was also rationalized in this way by some people. It was already done at the times when the author of Ping was alive. He was just you laughing on that, but Yes, that that's we are. Um what is maybe the most interesting about ping

is that um it not only became the verb in itself as like a official word so the consequences of actually introducing this utility and the whole thing it's it it it it it they are pretty big like these days people use word like ping ping me who are far away from computer science you know the people who play computer games for them pink has their own meaning so you know how faster how how how how big bigger how how well um is the uh latency for your connections. So it was pretty big cultural um uh reference which this word had uh on the more than life. And of course from back in the day, here I have

a little joke that system administrators as always tried to like you know to make a fun of. that I ping my fridge to make sure it's still online. These days uh in post Internet of Things uh era that sounds already a little bit regular right because okay ping in the fridge okay why not I usually have Wi-Fi connection to my wash machine and ping in the fridge is nothing really but uh back in the day it was still you know pretty much advanced Um my time is go go. Okay. Uh let me see what I have. Maybe just the last one. Yeah, let's make it make the last one. We will

skip the kernel and shell because yeah, well. Let's let 's do it a little bit. So I will skip kernel, but let's go with the shell. So um Shell was introduced uh by a French computer scientist Louise Pouzet, probably, um, because He wanted to have some kind of the interface between the person and the computer. So you should think that at that time when we are uh speaking of those first m Linux's first uh uh you sorry Unix machines or even before the Unix mainframes, people were interacting with the machines, you know that's brutally writing into the memory. So something we kind of dislike these days, especially with Python, uh everything is controlled, everything like that.

Not in not not at this time. At that time You brutally write something into the memory and it can just you know die out because someone made a mistake. So this guy said no it's not good and introduced the command language called Runcom. Like abbreviation of run commands. And it was meant to be the interface as we would call it because it was the terminal interface, TUI, as we call these days, something which should protect the kernel So the main of the system, uh and uh from uh us users. And that's why it was called shell. So something what protects in, even though uh yes it's interface. What is interesting though The concept was popularized

mainly and heavily by Dennis Ritchie and Ken Thompson. So when they introduced Unix. Very interesting paper by the way, original one. I've skipped it, but um if you like I can point uh I can I can send you the link. It's uh publicly available. uh very uh interesting paper where they introduced the the the Unix as itself. Um just interesting to read how the things didn't really much evolve over in in the last let's say 30 or 40 years. uh after the introduction. But um what is interesting um you've seen those endings RC right in your configurations on your Mac

or uh Linux Where do they come from? What do they mean? No idea. Actually, those are exactly the remnants of Rancom, of this initial first uh shell created by uh by by Dr. Pusin. So those are abbreviation for run command or and they were stemming from uh from this very nice uh 1965 version of uh original shell. Finally, still alive? Bucks Bugs are everywhere. You know, no bugs, no job. It's pretty simple. Our job, you know, is just to write bugs. Someone just write more, someone

less. No bugs means no work done, right? So that means just you know depending on the qualification of the software developer. uh is the amount of of the bugs you kind of produce, but nevertheless our job is in the end to write bugs. So um They are called also errors, faults, defects, whatever. And yeah, it's a pretty rhetoric question. What has this thing on the right the most Month nothing to do with the cabinet, which in fact is not a cabinet, it's a computer. I'm pretty sure that you've heard this very nice and interesting story. It's called

from um it was logged by Grace Hopper. That's uh it it it was it's you see it's a page from uh Harvard Mark II Electromechanical Computers Lock featuring a dead mod that was removed from the device. So they found this mod which caused the the the circuit breakage. It's a first actual case of a bug being found. Very nice, very nice anecdote. But it's not origins of the word bug, in fact, at all. At that time when she wrote that, the word bug was heavily used and the only what made it a little bit different. is that uh she already kind of make a fun that she connected the the biological buck with the buck uh in in in

in the system. That's why uh it was kind of funny. But in fact, the traces of the buck can be uh we can can can go pretty far back uh into the nineteenth century because already in engineering the term buck meant something um something not working or something that is unexpectedly produces the problems. Here is the quote from um uh Thomas Edison. Um it has been just so in all of my inventions. The first step is intuition, then comes Uh and comes with the burst, then difficulties arise. By the way, sounds like a typical software engineering. Then difficulties arise. This gives out, and it is then that bucks, as such little faults and difficulties are called

show themselves and months of intense watching, study, and labor are requisite before the commercial success of success or failure is certainly rich Certainly is a very nice thing. In our case it's not always certainly. Most of the times it's uncertainly or never reached, but um yeah So this was a very nice story. I think many of you have heard it, especially when you started with the computer engineering. You know the bug which was found in the big mainframe. But it's it's still like merely a joke. By the way, the same story about the buck was presented to me when I started learning all that a bit differently. It was already more modern approach. then the bucks were residing in laser printers because it's really warm inside

and that's why they are called bucks, you know, because someone found the bucks in the laser printers. So uh the folklore of software engineering evolves with time And uh yes. And that's it. So I would like to thank you for holding such a long time, 32 minutes. But what is important message of all that? We kind of um tend to think about the software engineering as very like separate field from everything else. But in fact it's not. It has the roots and connections to all other disciplines like mathematics, philosophy, engineering, design, everything. And the foundations and the field itself, which we kind of

hopefully call the our industry as a software development industry, was built by uh m mostly by people actually from our uh from our fields and other disciplines. So we should be definitely grateful to all of them, not only giants by the way, because of course there were giants. There were people who were mentioned on those slides and have some articles on Wikipedia. But there were hundreds and thousands of other people who were, you know, uh just a regular worker inside of the groups like all of us are. But they were slowly, continuously driving the field forwards. And let's thank to all of them.