Greetings, and welcome to episode 19 of taking apart a Monroe K series calculator, actually putting it back together again. So I'm Rob. You'll notice some differences. The previous episode actually had a very short intro section that just said 18. And it had some music, which is kind of cool. It's Creative Commons music. So I put the link to where you can get that down below. So check it out. Anyway, so this is episode 19, and according to the episodes that we have previously done, we are currently working backwards, putting the machine back together again. We are now working our way backwards through episode 9, which is taking apart the keyboard mechanism. And, of course, we will be putting it back together again during this episode. So what I've done is I've laid out all the parts, and since there are very many parts, I can't actually get it all in one shot, so I'm just going to do this handheld. And that's why you see me, because I'm doing a little introduction. So let me show you all the parts. So here we go. Here is basically a wide shot of all the parts that go into the keyboard mechanism. So the microphone is not doing so well. So here we have the plate that all the little keys go into. These are little things that go on the sides of the plate. And you can see these little U-shaped indentations. That's where the carriage movement axle goes. These things are for locking and clearing the keyboard. These things are these sort of bars that go across the plate, so that when you press a key, they actually lock the key in. This sort of double axle thing is the mechanism which actually clears the keyboard out.  There's a lot of them, well, 80 of them, because this is an 8x10 keyboard.   There's a little thing with a set screw in it. And also these other funny non-round shapes are actually key stem locks. So you can probably see how it all works in episode 9, but we're probably just going to do it again explaining it. Now the reason that these are on napkins is that what I did was I took this stuff, I took this stuff, industrial maintenance coating thinner, which this is a California product. See, it says use in place of MEK, toluene, xylene, and blah, blah, blah. That's all stuff that is not legal to use in California because cancer, I'm sure not that this doesn't cause cancer, I'm sure it does, just like everything else, I guess. And here is a bucket and a toothbrush. So basically what I did was I poured some of this into the bucket. And with the toothbrush, I just basically cleaned this plate. Oh God, was it dirty. All of these larger parts I cleaned with the toothbrush. All of these parts I then dumped into the bucket, poured the thinner over it, and then just agitated the pail for about a minute or so, and it came out really clean. These especially were almost black with grease. And all I did was, again, I just dumped it into the pail, agitated it for a minute or two, and then pulled them out, and they were nice and shiny. Same deal with these. I mean, these were really gunked up. So anyway, that's what I did. And what's left, in fact, let me move the microphone again, what's left is this bag. And in this bag, I'm not going to open it yet, are all the pieces of felt. I think there's probably 160 pieces of felt, or so, two for each key stem. I also left all of the screws, there's a screw, and all of the springs in here. I didn't want to clean them because they're kind of really small parts and I didn't want them to get lost. So I could probably hand clean them or they may not even need to be cleaned. So those are all the parts that go into the keyboard, and now we will put the keyboard back together again. All right. To put the keyboard back together again, we've got to work backwards. The first thing we've got to do is take the plate and orient it properly. So to begin with, what we're going to do is place the plate so that these standoffs are facing up and so that this notch is to the left. Next thing that we're going to have to do is pick one of these and put them on this side. So the question is, all right, well, is it this one or is it this one? And you can see that they are slightly different. One's got a bigger U than the other one. But the way you figure it out is that you can see that there are these pins on the end, and they, when they're put onto the plate, face inward. And the reason for that is that these bars have little holes on the end, and the holes go on the pins like this so that these can rock back and forth. And the only way for that to happen is if the pins are facing each other. So there's no pin on the other side. That means that, and the U, must go on the right side. So that means that there's only one of these that can possibly fit so that the pins are facing in and that the U is on the side and that is this one, because this obviously isn't going to do it. So what you do is you have these alignment pins and you have these holes for screws. And you simply put that in and it just goes in like that. Now the next thing that you have to do is apply some screws so that we can attach this to the plate. So we have, I've taken the felt out of the bag along with the smaller parts. We have ten springs. They all look approximately the same. One is slightly smaller, but I'm not sure that that matters. And then we have six small screws and two large screws. So the first thing we're going to do is, on the plate, we have basically four screw holes. We're going to screw the middle two using small screws. So let's do that now. I'm just going to take this, put it in there, that's one, two. And some of the small screws are slightly smaller than the others, but again I think that's just because the exact size doesn't really matter. And it doesn't look like they were any good at making precisely sized screws, anyway, aside from their threads, which of course they had to get right. So I'm just screwing this in with one screw, this is a magnetized tip so sometimes it just sort of hangs in. Okay, so there we go, alright. Now for this, we have these side pieces. And these side pieces hold this in place.  So let's see how we put that piece on. So first of all, it's important to orient this piece the right way. So it looks like this is going to go, I'm looking at the video right now and I'm trying to see, I'm pretty sure, uh-huh, okay. So this is actually going to go like this, with the lever on the side opposite the notch, like that. And we have this bushing which goes over here and that will eventually hold it in place. So the next thing is these things.  So obviously it will either go like this or like this. So we have to figure out which it is. So in other words, this is either going to be held off the board or it's going to be held on the board. So I'm just going to very quickly consult the video and it looks like it is actually held off the board, like that. And in fact, I think I may be incorrect. I think this may actually go, let me just orient this the way the video is showing. So it looks like it's like this. Okay, I'm just holding it up like this, right? No. There we go. I got it oriented the way the video is showing. I think that's correct, yes. Now according to this, it looks like we're holding this up like this. So actually, that's right, okay. This lever is on the same side as the notch. And the reason for that is that there is a spring that goes from this hole in the lever to this hole on the edge of the plate. So that's why this goes like this. And then it is actually held off the board, which means that when I put these on, they basically have to go like that, just like that. So what I'm going to do is, let's see, can I, if I were to, I'm just planning this out a bit. Yeah, right. So I'm trying to figure out whether to screw these in first. Well, I guess it doesn't really matter. So I'm going to screw in this one using the long screws, right? Because we're moving through more material, and that's why two of the screws are longer. So I'm just going to screw the one bushing into place, great. It's kind of odd the way that this hole is elongated, because that sort of implies that this thing could move back and forth. But of course it can't, because that screw fixes it in place. So I'm not really sure what the deal is on that. Okay, so then we will put this other one. Now if I do that, the question is, can I get this in? Probably. I don't want to put the axle in first, because then I won't be able to put the screw in. Because the axle is in the way, and that's no good. So again, using a long screw, I'm simply going to put the bushing in its location on the other side of the plate, screwing it in with the long screw. So there we go. So now I take the axle, and on the long end I'm going to insert that over on the left side. Okay. Now I can just insert it on the right side all the way, basically, or almost all the way. Because the next step is, we're going to take this bushing with the set screw, and we're going to, does the set screw go inside or outside? It actually goes inside. Okay, so I didn't do this correctly. The bushing goes on first. Actually let me put some oil on that. I refilled my oil container. So let me just put some oil on that, so that it's easy to go on. And so that it doesn't, I don't know, rust in place or something. Okay. So I'm going to put that right on there. Nice. I'm also going to just put a drop of oil on each, on the inner side of these surfaces and maybe a little bit over here, because this is actually going to be a moving part. So all right. So now I just put the long end in, put the short end in. Now I move the axle, the bushing over, like that, to fix it in place. See? It doesn't move. Now because these two surfaces are touching and they're going to be moving, I'm going to put some oil on there as well. Okay. And the same thing on this surface. Okay. Great. Now I'm going to take my screwdriver and holding the axle in position. I'm going to tighten the set screw. Set screw is tightened and there it is, distributing the oil a bit. Okay. It's not, it doesn't move completely freely. There is obviously friction. You can see that it is holding its own weight. But I don't think that's too important, all right? I can put the spring on now. I'll just use the spring that's small. So the spring will go on one end. So these are hook end springs. They're called hook end. The reason is that of course it's a spring and it's got a hook on the end. So you've got to put the hook into the hole without actually distorting the hook. So there's one and then over here, I'm just going to put that in there, get it in to the hole. There we go. So that's how that works. Okay. Now you can see how the zeroing mechanism now works because we have two different types of key stems. One is a zero key and the other is 139. The zero key stem would of course fit in like this, see? So that this tab sticks out and obviously when I pull on this axle, it's going to pull on that key stem if the key stem were perfectly straight up and down, which of course it's not constrained to at this point. It will be when we put it in the casing of course, but for now that's basically how that would work. So this would pull the zero key down as if you were pressing it. Next thing that we're going to do is we will turn the plate upside down. So we have this rail over here and on the rail are eight little holes and those holes are four springs. These guys. So we have nine springs left. We're just going to separate off eight of them. Again they're the same size or approximately the same size so we can just pick any one. And what we're going to do is place the screws so that they are hooked in and they basically just hang right over there. And these springs are specifically for these little bars here. And the other end of the spring goes into this hole. And then, or is it this way? Yeah it's this way, I'm pretty sure. So if I put one of these in place, get on there, okay and imagine that it's held on the other side. So this spring is going to go over here and it's basically going to hold this bar into place and the bar can rotate this way and the spring will pull it back this way. The reason for that is that the key stems have these funny little cutouts over here. And when the cutouts are, I think I would have to put this stem through one of the holes. Let me do that, that, okay. So you can see that if I push the key down now, it's kind of hard to see, but if I push the key down, that will rotate the bar and then the bar will snap back into place due to the action of the spring and then this is now pressed down in place. In order to clear all the keys, basically what you would have to do is have a bar running the full length, pushing all of these rock bars like this whereupon this can spring back up and then you release it and it just goes like that and then you can press this down again like that. So that's basically how the keyboard works. Here is the spring that goes on to the key stem that forces it up when the bar is released and then it springs back up. So that's basically how it works. So let me take these out again. So that's why we have these eight springs because there is one of these bars for, there's a bar for each row. So I'm just going to put these springs on. I thought I might be able to do this by hand, but I guess not. So again these are hook ends. So I'm just going to take the spring and hook it over the end. In terms of whether it gets hooked on like this or like this, it doesn't really matter because it'll just stay in there in the end so you can just do it whatever way is most convenient for you. Again, pulling gently, pulling just enough to get the hook over and into the hole without actually bending the hook. So here's spring number three. I'm just going to pull it slightly and then put it into its hole, oops, totally lost the hole. There we go, number three, number four, number five, and I'm doing this first rather than after all the key stems are in because you can see that it's a lot easier to put the springs in before all the key stems are actually sticking up here and getting in the way. So now one thing that occurred to me is that after I cleaned all of these metal parts, I did not apply anything that would prevent rust and I'm not sure if that's a mistake or not. Clearly on all the moving parts I put some oil on there so that's obviously going to help. But in terms of the surfaces and the non-moving parts, I don't know, I mean I heard bad things about WD-40 so I'm certainly not going to use that. There is, Crudcutter makes a derusting liquid or stuff that is supposed to simultaneously remove rust and protect the metal against rust, I don't know. So I'm just going to leave it like this and kind of hope for the best. Besides in 30 years the singularity is going to happen and we won't be around to take apart these calculators so nobody is actually going, so there's not going to be enough time for this thing to rust. 2045 is when the singularity happens and we'll all upload and have a great time. So anyway, okay so that's that. So the next step is we need to put the key stems on. So we'll start with the zero key stems and what I want to do is basically put the key stem in here from the bottom, right, so it goes in like that and I'm not certain whether I have to put a washer with a piece of felt in there, here's a washer, here's a piece of felt, I think I do, and that goes in like that. Well obviously it would have to go in. Let me just check the video to see if we do get washer and felt on the underside. The reason that we would put a washer and felt is for example for this key stem, which definitely takes one of these. So we put a washer first and then a piece of felt and that goes in like this. So when the key gets pressed down, this happens, but then the key, and there's a spring on the other side, so that when the key gets released, it smacks into the plate. And obviously you don't want that smacking sound to be very harsh and metallic, which is why they put this felt over here. So they would do that and then on this side they actually have a spring, okay, and then this thing, this little piece actually fits into this notch over here, this little slot, and holds this in along with another washer. So that's how the spring gets held on. So basically you do that for all the keys except possibly for the zero key. So I'm going to check the video on that, and then I'll come back. Alright so I checked the video and indeed, at least according to the video, which I believe, each one of the zeros does take a washer and a piece of felt. So it's difficult to put the washer and felt on first, like this, and then stick this in because the washer just sort of gets in the way. So you can see that it's good to put these zero key stems in first because that tells you the orientation of the notches. Because if this were oriented like this, then this little tab would not be able to hit the axle, which means that the notches must go like this. So what I'm going to do, I guess, is I'm going to, let's see, can I swing this out of the way? No, because if I swing it out of the way I'll never be able to swing it back. So basically I'm just going to put the washer and felt just on the plate and then move it in place. That's it. That's all I have to do. And then I have to pull on it a little bit. Why isn't it going stuck on something? I think it's stuck on something. There we go. Okay, so basically that's this side and then on this side, I'll turn the plate around like this. The first thing you need to do is put on a spring. So here's a spring. Just put it on like that and this will work for all the other things as well. The next thing that you need to do is take a washer and just put it on. And the final thing we do is take one of these locking things and you take pliers and you hold on to the locking bit and we're going to, let's see, how can I orient this? I guess that's okay. And what you have to do is push down on the washer, stick the thing inside, which is kind of difficult, but it can be done without dropping anything. So once you get one or two of these done, you kind of get the hang of it and then you can do the rest of it pretty quickly. So you just sort of jam it in there and it locks in place like that. See? That's how it works. Now of course, because this key has freedom to move like this, it's not going to move very smoothly unless it's perfectly straight up and down. And that happens when the top plate gets put on. So anyway, okay, so I think it's time for a time lapse. Okay, so I'm actually going to stop here and the reason that I'm going to do that is, first of all, you can see that we've pretty much run out of felts. We have four, probably seven left and we obviously need 12. So number one, we're missing five. And number two, these are the worst felts that there are. Some of them are just ripped. Some of them have been flattened out and distorted. So I'm just going to go to a craft store or something and get some more brown felt and then cut it into a circle and then just cut a slot into it somehow. So that's the easy part. One thing that I did notice as I put this together and I'm not sure if you can actually see this, so I'm going to put, so you can see that one of these stems is different than the other. One of these stems is not the same. So this one on top is actually bent slightly and I'm feeling it and I can actually feel the metal having been distorted right over here. Now I could bend it back, but the problem is that whenever you bend metal, you fatigue it. So this will be quite fragile. I think I mentioned a while back that I had actually 3D printed one of these. It was actually a curvy bit. So what I'm going to do is I'm going to get another one of these 3D printed that's flat and just use that instead of this. That's the nice thing about 3D printing. The bad thing about 3D printing is that it's still quite expensive. I don't remember how much I paid for that little piece, but I suspect that this is going to be anywhere between $15 and $30, which if you think about it as compared to the cost of one of these things from eBay, it would be ridiculous to actually, it would not be economical to 3D print something like that. But the alternative is to take one of these machines from eBay and use it for parts and basically just say that you're going to basically take one out of circulation. If you really wanted that one back into circulation, you would have to replace all of its parts that you pulled off of it. So in the end, I guess it sort of evens out, but yeah. So the point is to 3D print or not to 3D print or to replace or not to replace. And I would argue in favor of replacing because if you don't replace, then you're taking one machine out of circulation, at least one. So let's see. Just make sure we have all the parts that we think we're supposed to have. So there's five, well that's weird. We've got some parts missing. Oh no, we don't, sorry. There are eight per row. So there we go, eight and two. So yeah, and therefore we needed 10 felts and we have seven felts here. So we are missing three felts. And in terms of these, as I was putting these together, I was looking at this small part really wondering what I should call it. It looks like a t-shirt, so I'm just going to call them t-shirts. So obviously we need 10 t-shirts and 20 washers. So we've got five washers, we've got 10 washers, we've got 15 washers, 20 washers, 26 washers. What? Did I count that right? I know we have 10 stems, oh yeah, because I didn't put on the tops of these yet. So that would be 26 washers in total. So that means that in terms of t-shirts I would need 16 t-shirts, so let's just make sure I have 16 t-shirts, that's four, eight, 16 t-shirts, good. So I've got all the parts, with the exception of the one bent key stem. And I'm going to replace all of these felts because these are all distorted or ripped. And oh, and we have springs. I'm just going to sort of assume that we have the right number of springs because why wouldn't we? We seem to have all the parts anyway and we were very careful in putting parts back into bags. So that's going to be it for this episode. When we return next time we're going to finish the keyboard assembly and I guess that means we're going to move on to the main frame, which is kind of cool. So until next time, this is Rob signing off. See ya.


Hello, and welcome to FuturePath. I'm Amarico Forresteri, Director of External Affairs at the NASA Lewis Research Center in Cleveland, Ohio. In NASA's goals to try to fly higher, further, and faster, new materials and structures are required to meet these goals. In today's segment, we're going to look at some of the things being done in our structures division on structures for flight propulsion. I think you'll find it interesting. Let's watch. MUSIC Flight in the air or in space requires propulsion systems able to withstand extremes of mechanical stress, vibration, and temperatures. Designing these structures and matching available materials to the job has always been a complicated business and is becoming more so. Requiring safety and reliability from structures needing minimum maintenance and having the least possible weight poses a basic contradiction which can be resolved only by the most sophisticated analytic methods. The Lewis Research Structures Division is dedicated to advancing the state-of-the-art of structures technology for aeronautical, space, and terrestrial applications. The principal product of the division is the development of validated analytic methods to predict the behavior of structural components and systems for aerospace propulsion and power machinery. The division provides not only solutions to problems encountered in current applications but also leadership in setting new directions for structures engineering to solve tomorrow's problems today. The purpose of the structures division at Lewis Research Center is to develop advanced, credible design tools. These tools can then be used by designers to design advanced concepts for future missions both in aeronautics and in space. We develop these methods for use on high-speed computers and they are validated with the state-of-the-art laboratory equipment. We can predict the life, that is, the number of missions that can be flown by the advanced concept and we can optimize the design both from the point of view of minimum weight or from the point of view of lowest cost. Breakthroughs in flight usually follow developments in propulsion systems. In the early days of flight, structures design was a combination of art and trial and error. If you were developing a rocket, you built an engine derived from earlier designs. To be sure it didn't fail, you made it sturdier, heavier. As technology advanced, lighter, stronger materials and improved manufacturing methods made the impossible possible. The breaks were still made and the results were spectacular and costly failures. The job of the structures division is to make sure such accidents will no longer occur. They do this by applying the latest scientific analysis possible and by using the most up-to-date testing equipment and methods available. To do this, the staff of scientists, engineers and technicians of the division perform work in structural mechanics, structural dynamics, T, fracture and on projects and applications. Some of the work in structural mechanics includes characterizing the properties of metals used in propulsion systems. By subjecting specimens to stress and varying temperatures, researchers can predict maximum loading and operating temperatures. And testing is performed at very high temperatures on materials that will be used at places like the leading edge of the national aerospace plane cowl. The work in structural dynamics focuses on the forces affecting bodies in motion. When the turbine in a jet engine loses a blade or even during a very hard landing, the vibrations that occur can cause a propulsion system to fail. Tests in dynamics can simulate a blade loss condition to provide test data to compare with simulation models. Any rotating machine will tend to vibrate at certain critical speeds. And since modern rotating equipment is required to operate at ever higher speeds, this problem is increasingly important. Research in the division is developing methods for both active feedback and passive suppression to permit operation of equipment above critical speeds and to reduce bearing wear. High-speed computer simulation is required for the full dynamic analysis of rotating machinery. Parallel computing developed in the division is making this possible. By combining a large number of processors in one transputer, computations can be performed rapidly enough to study high-speed vibrations of rotating components. Studies in fatigue and fracture analysis are performed in many of the structure's division's labs. Both destructive and non-destructive methods are used to evaluate and characterize new materials. And sometimes a combination of both are used to improve the analytical process. Much of this work is directed toward characterizing and understanding advanced material systems. As an example, researchers in the division sonic map a ceramic disk and send the data to a computer. The computer outputs a color simulation showing variations in density, defining areas where fractures should occur. Later the disk is placed in a hydrostatic chamber and fractured. The actual fractured disk is then compared to the computer model for verification. Division researchers also test advanced fiber-reinforced composite materials under varied loads expected in aerospace applications. Data collected from these tests are used to verify mathematical models which describe the material behavior. These models are then incorporated into NASA computer codes and used to predict the performance of composite structures in a variety of applications. Beyond solving the problems which can lead to failures, the division provides leadership in developing new concepts and integrating information from many sources for application in areas ranging from windmills to the space shuttle main engines, from fuel-efficient propellers to computer codes for production design and propulsion system simulations. The work of the division provides verified mathematical models and computer codes that are key elements of today's computer-based design analyses for flight propulsion systems as well as many other systems with similar problems. Using the products of the structures division, designers can better predict the life of a component by constructing it on the computer, thereby saving time and material while preventing costly failure. Future aerospace systems will require advanced capability. On-board computation and real-time sensors will combine to make it possible to monitor the health of advanced systems. Active elements could be included to make it possible to suppress dynamic instabilities. Structural tailoring to account for local stresses and local hot spots may be the only way to take advantage of the new lightweight, high-temperature yet very brittle materials. Computational simulation will allow designers to make rapid, affordable, and feasible designs. Probabilistic methods will allow designers to quantify risk and make trade-offs between performance and life. Combination of these capabilities will allow those designers to operate and design closer to the limits. Such capability will allow us to build systems that we couldn't build before to carry out missions that conceivably couldn't be carried out with the development of these capabilities. The structures division hopes to play a major part in bringing them about. A special combination of experienced in-house staff and facilities in the Lewis Research Structures Division has been tailored to meet the challenges and needs of the new age of spaceflight and aviation. The work of the division continues to evolve technology and will take us into the next generations of flight. Our second segment is about a process developed at Lewis that we're very proud of. An engineer in our materials division developed a process called arc-sprayed monotape. Let's find out about it in some of its many uses. Unfazed by extreme fire-hot temperatures, possessing amazing strength, a strength beyond belief, its creation, one of outstanding engineering achievement, the new, the ultra-advanced composite materials being developed by NASA Lewis Research Center in Cleveland, Ohio. To understand this fascinating field, we must start with basics and determine exactly what is a composite material. Possibly the easiest way to visualize a composite material is to offer the example of a tennis racket. The arm and frame part of the racket is made by combining two distinct materials, graphite fibers, which give it strength, and a low-temperature glue or binder, which hold the fibers together and allows it to be fashioned into shape. This is a composite material. Two different parts, each with a different function. Research in this area began about 25 years ago when minute whiskers were discovered growing on electrical devices. The whiskers were found to be single-grain crystals that, when tested, proved to be very strong. In later research work, the whiskers were used in the making of bulk materials. Today, instead of whiskers, fibers like silicone carbide, tungsten, and graphite are used with a glue or binder to make such things as engineering and sports products. There are some products, though, that need to be able to withstand higher temperatures. At the same time, it's also necessary that they be lightweight and stiff, which, incidentally, are very important requirements for just about anything intended for use in space. To meet the more demanding requirements, a glue or binder, such as aluminum or titanium, may be used. For other products that need to be heat-resistant at even higher temperatures, a nickel or iron-base alloy is combined with either certain carbide fibers or tungsten fibers. There are several ways to do this, and one of them is the arc spray process. This method was developed right here at NASA by one of our engineers, Leonard Westfall. He works in the Advanced Metallics Branch of NASA's Materials Division. Recently, Mr. Westfall described exactly how the arc process works. The process works like this. We have an arc spray gun which is attached to a large vacuum chamber. Inside the vacuum chamber is a drum that has real strong fibers wound on the surface at a very regular spacing. The arc spray gun works by having two metal wires coming into the gun, and an electric arc is struck between the tips of the wires. The electric arc is sufficient intensity to cause the wire tips to melt. A high-pressure stream of neutral gas, and we usually use our gun, a very clean our gun, is sprayed on the molten wire tips, causing the molten metal to dislodge from the wires and to be vaporized into very, very fine particles and sprayed, and we aim it right on this drum surface. The thin sheet that's formed can be as big as the drum surface. The thin sheet Mr. Westfall was talking about is called a monotape. It comes off the drum very easily because a Teflon spray is applied first. The spray allows the material to get hard and yet not stick to the drum. It simply peels off. Composite monotapes are used to make composite shapes which are rather complex structures requiring extremely high strength. In order to make the structure as strong as possible, the monotapes must be positioned in certain directions. To do this, the monotape is cut into small pieces and stacked one on top of the other. On the first piece, all fibers are placed in one direction. On the next piece, the fibers are put in the opposite direction of those on the first piece. This alternation of the fibers direction is continued on the pieces in order to maximize the structure's strength in different directions. The small pieces of composite monotape usually are glued together by a method called hot pressing. Very heavy pressure is applied to the stack while it is subjected to a temperature of almost 2,000 degrees Fahrenheit. As the metal gets squeezed together, any small imperfections in the monotape disappear and the metal pieces blend together resulting in a perfectly solid plate. Cut into thin strips, the plates are used extensively at NASA for testing purposes. Engineers have been able to make large tubes by using a pressing guide to shape it. They have made demonstration turbine blades for jet engines. These blades are located very close to the place where air mixed with fuel is burned. As combustion takes place, the expanding gases hit the blade, causing it to turn. It's easy to see why the blades must be able to withstand extremely high temperatures. Presently, there are five NASA programs in which arc spray monotape plays a major role. Two programs deal specifically with the space shuttle's main engine. Since the material now used to make the main engine is cracking due to thermoshock, NASA is working with tungsten reinforced superalloys to replace it. These composites, in tests so far, have proven to be more shock resistant, stronger, and able to withstand higher temperatures than their present material. The second program deals with the reinforcement of a combustion liner in the space shuttle. Mr. Westfall explains. A combustion liner is a contoured shape that is liquid hydrogen cooled, and it's the vessel that the liquid oxygen and liquid hydrogen burn in. You have very, very high temperatures inside this combustion liner, and typically it's made out of copper or a strong copper alloy. The problem this combustion liner is experiencing is the copper alloy is deforming due to the very high temperatures and the stresses that are generated in the thin inner wall, causing the inner wall to deform and actually crack, and the liquid hydrogen is leaking out. We are putting tungsten fibers in the inside layer of the combustion liner to strengthen, to selectively strengthen the inner wall of the combustion liner. This is an example of one of the test specimens that we make, and we have tungsten fibers reinforcing the inside surface of this specimen. This specimen then will be tested in a rocket test chamber under conditions very, very similar to the space shuttle main engine, and the material will be tested to failure. We predict a much longer life with our tungsten reinforced copper than the current copper alloy that's being flown in the space shuttle today. Also regarding space, the third program has to do with the creation and development of very strong tubes to hold liquid metals and heat pipes for nuclear reactors. Because of the tremendous pressure the tubes will have to withstand, a new material is needed that is much stronger than the one now used. Using the composite process, engineers are adding tungsten fibers to the present material to strengthen it. And again, in support of space power, the next program is working to develop a specific container that will be able to take high temperatures and amounts of pressure which the current container cannot. In this case, the power being generated would be for a space station. The composite material that has been developed is three to four times stronger than the present one, surpassing the program's goal of finding a substitute container for present temperature and pressure levels. The engineers at NASA have created one that can be used as power demands go up in the future. The final program developing composite materials for use in space deals with the improvement of radiators. Again, NASA engineer Leonard Westfall explains. These tubes I talked about before have radiator panels hooked on the back of them to get rid of the heat. We're developing fiber reinforced radiator panels that are made out of graphite fibers that have very, very high thermo-connectivities, and thermo-connectivity is the material's ability to conduct heat very quickly. These fibers conduct heat extremely fast, and we put them in copper as a high-temperature glue. Copper also has very high thermo-connectivity, and so what we end up with is a structure that has higher thermo-connectivity than copper is very, very stiff and light. And this saves weight. It increases the efficiency of the radiator panels and makes the whole cooling scheme work much, much better. At NASA, there is also very exciting work being done to support the National Aerospace Plane. The plans for this remarkable plane call for it to take off from the ground and fly up, right into orbit. It would fly like an airplane, but its jet engine at higher altitudes and speeds would become like a rocket and boost it into space. NASA's Advanced Metallics Branch is working on developing a fiber-reinforced inner metallic material out of which to build the plane. Currently, the plane severely lacks a suitable material. There are three vital requirements that the material must have. It must be lightweight, highly resistant to extreme heat and very strong. Since it will be used primarily as a major structural component, the composite material being tested and developed uses ceramic fibers. The inner metallic matrix and ceramic fibers together form a material that could be the solution to one of the plane's most pressing needs. In all the research, in all of these programs, with all of the discoveries, breakthroughs, and amazing new products tested, and those actually in use, still, according to Mr. Westfall, the present work is, quote, just scratching the surface in composite materials. Besides the fibers in existence today, there are many, many others with great potential that need to be developed and tested. NASA's goal? To develop even stronger fibers that can work at even higher temperatures. Some of the structures NASA has been working on will be used for the National Aerospace Plane, or commonly known as NASP. NASP, when it is built, will have the unique capability of taking off from any airport and fly directly into space. Let's learn more about NASP. Imagine taking off from an airport runway, flying at 3 to 5 times the speed of sound. At altitudes of 20 miles or even higher.  Or maybe you took off from a runway and flew directly into orbit to work in space, and then you return, landing on a conventional airport runway. The National Aerospace Plane will try to make both scenarios a reality. NASA and the Department of Defense have done research on hypersonic technology for many years. The NASP technology demonstrator will be a highly advanced ex-plane, a new member of the elite special research aircraft that includes the X-1, which in 1947 was the first aircraft to break the speed of sound and fly supersonic. In the early 1960s, the X-15 became one of the first manned hypersonic aircraft and reached speeds of Mach 7 for about 4,500 miles per hour. One of the key technological developments of the X-30 or NASP are in the propulsion area. An air-breathing, hydrogen-fueled supersonic combustion ramjet engine, or scramjet engine, is now being developed for speeds from about Mach 7 to Mach 25. The engine uses the velocity of the vehicle to compress air as it is rammed into the intake. This compressed air is then mixed with gaseous hydrogen at this stage to generate high thrust. A development on which we will focus is materials. Here to speak on that is Matt Mellis. With the advent of the aerospace plane, there's become a need for a lot of new material development. Beyond a shadow of a doubt, we need new materials, and these new materials will most probably be composite materials, but instead of using a metal matrix-based composite, we'll be using, or epoxy-based, we'll be using a metal matrix-based composite. Metal matrix being copper, for instance. One of the big problems NASA is facing with the advent of the national aerospace plane deals with not only finding the right materials to use, but in cooling them as well. We have to figure out some way of making a very strong material that's going to survive in a high-temperature environment. What we're going to have to do is actively cool this material by putting some kind of a cryogenic fluid behind it, gaseous hydrogen or liquid hydrogen, which is very cold, and acts as a good heat transfer medium to take heat away from the leading edge. On one side of the material, on the inside of the wing, there'll be a lot of coolant rushing through to cool the inside down, and on the outside you'll have a very hot surface, and that is why we need the high-heat conductivity. For instance, you look at fighter jets that travel Mach 1 or Mach 2, or even the Concorde, which goes up to Mach 2. You see that their wings are very narrow at the leading edges, okay? And there's a problem with that because the smaller the leading edge gets, the more difficult it is to cool, and the hotter it gets because it's such a small... such a small point lying out there in the free stream that it gets very warm very quickly. The National Aerospace Plane is one of the projects being developed by NASA for future space use, but we cannot expect it to do all of our work in space. The National Aerospace Plane being something that will possibly be able to supplement the shuttle fleet or maybe even replace it, but obviously if you have an airplane that can take off from a runway and go to orbit with some people in it and go to the space station, for instance, or something like that, obviously it would be capable of shuttle-type operations. As far as payload goes, I think moving big things like space station components or say, for instance, they want to go to Mars and they have to get some big boosters up there, something like that. The National Aerospace Plane taking that kind of payload up there. The National Aerospace Plane is expected to yield a high payoff for the United States in the early 21st century with reduced space launch costs, vastly reduced transit time on long-haul air routes, major investments by private enterprise in commercial space ventures, and sustained U.S. preeminence in aeronautics with all of the social and economic benefits that accompany it. This is Amarico Forestry wishing you good-bye and hope you've enjoyed our show. I hope you walk along the future path again with me at NASA's Lewis Research Center in Cleveland, Ohio.


The skills you need to teach online, again, are very similar to the skills you need to teach in the face-to-face classroom. So I think one of the things that instructors might be intimidated about in terms of teaching online is they might be a little bit nervous about using the technology. And it's very important to know that you really don't need to be that technologically savvy in order to teach online. I think the biggest skill is having organizational skills and having a sense of what the course is going to look like from start to finish. That's really the biggest thing that I've found. The technological stuff can usually be taken care of through instructional design or through support at the university, which is great. But as long as you have a good sense of the content, as long as you have a good sense of how things sort of flow together logically, then I think it's very possible for someone that's even scared of technology to really excel in the online environment because those are the types of principles that the students look for. They're not looking for things that are incredibly elaborate. They're not looking for really sort of different technologies. They're looking for certainty in terms of what my expectations are. They're looking for a sense of what they're supposed to do every week. And they're looking for a sense of community. So all of those things are skills that really don't require a lot of technological savvy. I would say you definitely have to have some medium-level technical skills. You also have to have, I would say, empathy for your students. Some students will take online learning like Docs Take Two Other. Some students might be still reluctant, even though by all accounts everyone is on social media. And so empathy is one of the skills that you have to cultivate. How are students engaging this material? And also the other thing you have to learn to collaborate with other people. So now when you design a course, you're not the only person that basically drives the bus. There are other people on the bus. So there's people like Julia who you talk to about whether some of the stuff is feasible or not. So definitely it becomes more of a communal kind of affair. I think necessary skills for online teaching involve a basic level of adeptness at handling online tools. You have to know your way around the internet and you have to not be afraid of new learning in that regard. And I think that that to a certain extent has been a barrier for me because I'm not a technical person and I tend to freeze in the face of the first problem that I encounter. I tend to freeze. I'm not somebody who's going to tinker. And in that regard it's been really fantastic to have the support of our center here because they're at the other end of the phone or the other end of an email practically all the time. I think you need to be open to changing your pedagogical approach. I mean I think in order for this to work you have to be ready to grow. And I hope that we all are that way as teachers. But I found that I had a certain level of expectation of what I was going to learn and I've learned that much more. And that's been really exciting. The bigger the class and this is maybe not even an issue associated with online or blended but just maybe size of class and online classes tend to be or are often larger is you have to be very well organized. You have to have things prepared. You can't sort of do just in time delivery that a lot of profs like these you know as they're madly rushing to get everything ready for that day's lecture you can't really do that in the world of online or blended classes. You have to have everything all prepared in advance. So there's a lot of work that you have to do up front in order to make things run smoothly. I think that's probably one of the biggest differences that I would see anyway in terms of doing an online or blended class. You need creativity. You need to organize activities that could create a sense of belonging also for that online environment that otherwise could seem dry. So organize activities that could bring the students together. For instance group research, for instance online debate, activities that would warm up the atmosphere of the course but also speak directly to the outcomes wanted every week. So you need creativity for that. Okay so some of the skills I think that are required for teaching online is you have to have a different attitude around availability. In an in-class course you can expect to see them at least once a week, often more than that. And then you set up office hours so that you're reachable and the assumption is everyone's on campus and so they can come see you. But online students tend to at least in the classes that I've taught tend to work at all hours, tend to cover the material often last minute so you get a flurry of activity right before an exam and that can be frustrating but at the same time understanding that that's where the students come from and making yourself more available to answer is I've found to be more successful and on top of that then you have to adjust your communication style a little bit. They tend to be, a lot of the comments come via email or the discussion boards and as a result they're very informal, casual almost and it would be hard to imagine them asking the same thing if they were talking to you face to face but through this communication through the course management system or through email or they come across as casual. Adapt your communication to their level.  There are definitely skills that I've developed through online teaching. The biggest skill that I developed was instructional design and it's really impacted my face to face teaching as well. Sort of storyboarding the course and coming up with a project plan, coming up with set learning outcomes that were directly linked to assessment. These are the types of things that really can't be overlooked in the online environment and in some ways you can kind of overlook them in the face to face classroom because you're kind of making choices as things go along. So for me that sense of developing a course in a holistic way and making sure that everything is integrated was the biggest skill that I had developed teaching online and it's been a really big, it's had a very big impact on my face to face courses as well. For sure I've developed lots of new skills through online teaching. I'm getting to be a very good multitasker and just learning how to work with technology, learning about technology and not being afraid to use it and try new things.


你好,对不起,我的成文说得不好, and we thank you for your kindness and letting us continue in English. Thank you very much. Thank you for coming today here to the practical lessons from building a highly available open-stack private cloud. One thing right off the bat, all of the presentation slides, because people are always asking for presentation slides will obviously be available on the conference website later tonight whenever the organizers actually upload them, and each of you is very much invited to use these presentation slides for any purpose you wish under the terms of the Creative Commons Bias A3O license, which means you can use them for anything you want as long as you quote your source. Let me start by introducing to you Sebastian Kachel. Sebastian Kachel is one of the folks on the open-stack team at Pixel Park. I've had the pleasure to work with Sebastian and the rest of their very, very sharp team for several months now, and Sebastian is based in Berlin, Germany, and this is as about two-thirds of the people in the keynote this morning, his very first open-stack summit, so we can count him as a very new addition to our large and growing open-stack community. And this is Florian. Florian is H.A. Stowage, Cloud Guy, Consultant and Instructor. He is the Texas Co-Founder and CEO based on C-10C economy class, also similarly returns based home near Vienna in Austria. So what was the challenge to solve? We unsure the services that we provide with high availability, and so we must do this in our private cloud, too. And this is actually something that is a very typical challenge in the open-stack community. Generally speaking, open-stack users fall in one of two different groups. One group is the one that is primarily looking to open-stack as a massively scalable cloud platform for maybe a handful of applications that they are building. This is kind of like the group or the company or the team that is trying to build the next Twitter, or something of that nature that has equal scalability needs. What these people have in common is they typically have the luxury of maintaining only a handful of applications, which they can re-engineer if they so choose at essentially any given point of time, and the only constraints that they have are maybe time and budget. And then there is a wholly different group that looks at open-stack as a modern way of running a data center. And there you typically don't have the luxury of having maybe half a dozen applications that you support, but maybe half a thousand, or more than that. And in the first group, you have this luxury of, if I want high availability in my application, I can build it into the application, or into the handful of applications that I'm running, and that I don't care whether my cloud infrastructure itself provides high availability or not. If, however, I'm running open-stack as a way to run a modern data center, then I do have the expectation that my cloud infrastructure provides at least a certain degree of high availability simply because I'm not in any way capable of re-engineering a thousand or maybe more applications that I am managing. And as Sebastian is going to explain to us in a moment, Pixel Park, the company that he works for very firmly falls into the second category, so they're very much looking for an open-stack infrastructure that can provide this high availability to them so they don't have to worry about it at the individual virtual machine, the guest lab. Yes, so we are the different thing and we must bring the HA in the infrastructure. So let me take a little one about Pixel Park. So Pixel Park is a full-service agency for team communication and e-business solutions with the following departments like concepts, project management, editorial design, developing and hosting. So today we will show you the solution how we built HA in our private cloud. So why we use open-stack? There are so many other cloud softwares and I explained we are a full-service agency so we need the benefits of cloud computing like on-demand, scalable, elastic. It's very good that open-stack has fixed time-based release cycles. It is open source so we don't must pay for license. We can get support. It has a rapid development and this is a very important thing is that open-stack is a cloud software that goes beyond infrastructure as a service. So for a full-service agency with development as a department it's very important for us because they can use it for platform as a service and we can provide the services for the other departments and we make or we can make it highly available. So why we should use it's high available? I said that the other services that we have on physical machines that we provide the services are available and we must do this in our private cloud too. So in detail we provide service level agreements up to 4.9. So when we talk about 4.9's availability that's obviously less than an hour of cumulative downtime per year. The important part here is that if you have an SLA that mandates this kind of uptime then that means if you're thinking you can handle outages by having a person on call and you page them and then they log in and they fix it and you still think that you're going to be able to achieve 4.9's over the average of a year or maybe two years you need to think again. That doesn't quite work that way. If you are under an SLA that provides 4.9's capability or even 99.95% capability you are going to have some automated fashion of recovering from failures. That is to say you do actually need to build some form of automated high availability, automated failover into your system. If you're thinking anything else, if you're thinking you can guarantee a 4.9's availability SLA without some form of high availability mechanisms you're on the wrong track. So really very important stuff you actually need to build automated failover solutions into your infrastructure if you need to maintain an SLA just like this. And this is a very, very common criterion for a hosting provider, for a private cloud. There's very few customers that will accept less. And so for anyone who's building a private cloud that is an absolutely important concern. So how did we do this HA and OpenStack? First I will start on the base of the system and this is storage. So we need a high available storage and it must be scalable. And so we use CEPH. CEPH is distributed storage platform designed for excellent performance, reliability and scalability. So it guarantees real liable storage with no problems. And so no data lost. So what we should store in the CEPH cluster I think or re-sync, all it's impossible. So we store Cinder volumes, Glance images, Static data over Radar's Gateway and the three and we store instance data. So CEPH is an excellent storage, cloud storage for us. So how did we build it? You can configure CEPH or you can configure the copies of data in CEPH and we are rocking with three copies. So 66% of the physical nodes can crashed and all data is available with three copies. We used one disk per OSD. So under the OSD is no write, they are standalone because you don't need it. Over the OSD is a XFS file system and we put the journaling on separate solid state disk because it's faster. So every storage node has eight gigabyte ports and trunk mode because you have fast connectivity to these storages. And most of these are just basically pretty much standard best practices for any CEPH cluster. Can we have a quick show of hands please, who in here has built a CEPH cluster either in testing or production at some point? So as we can see the technology is such as getting traction because when I first asked this about two summits ago there were significantly fewer people in the room that were raised their hand. So this is a relatively cookie cutter straightforward CEPH OSD configuration. This is using the XFS file system as a sort of a balance, a trade off between file system features and file system stability. If you want the best optimized file system for the CEPH store as such for the CEPH OSDs you will probably go with ButterFS. But then you might be the kind of person that says well ButterFS is two years away from production and has always been and will always be, but only if you're cynical. But I think we all agree that ButterFS is currently in an experimental state. So XFS as an OSD for production system is generally a really, really good trade off between performance on the one hand and stability and reliability on the other hand. This whole thing with one disk per OSD, one thing that's nice about CEPH clusters is it takes care of all of the data redundancy for you. That is to say you can run your CEPH OSDs on simple JBODs so you don't really worry about rate controllers or that kind of stuff anymore. And the part with the journaling on a separate SSD is essentially performance consideration. CEPH when used with XFS uses write ahead journaling which means that all writes first go to a journal that determines your write latency and then later on they actually go to the actual file store. So if your journal is reasonably fast such as when you're running an enterprise SSD that generally speeds up the performance of your CEPH cluster as a whole. So like I said all of these are sort of general best practice recommendations that most people choose to follow when they deploy CEPH with the XFS file system. So this is the storage. The next layer I will explain is the open stack block storage. So this is Cinder. The Cinder services are Cinder volume, Cinder API, Cinder schedule and we put it into pacemaker. So pacemaker monitor and control these services over these two nodes. The services are running in active backup mode that means they are only running on one node or services and when one service crashed pacemaker moved it to the other node. The connectivity, the network connectivity to these storage gate rays is four gigabyte ports in trunk mode. The reason why it's actually relatively simple to put these services under a pacemaker high availability manager is that when used in conjunction with CEPH RBD, so that's the RayDOS block device that Cinder uses here for backend storage, the services themselves are essentially stateless. So the services themselves don't keep any local state about themselves anywhere except in the relational database that they write their persistent data into. The RabitMQ or AMQP in general message queues that are used to communicate between the services and the actual data lives in the CEPH store itself. So that means failing over a service, a Cinder service, a Cinder API scheduler or a Cinder volume service is a relatively simple process of just firing up the processes, the services themselves. There's nothing that we need to worry about in terms of actually getting the state over because the services as such are inherently stateless. So that makes the failover actually very clean and very fast and specifically in conjunction with CEPH RBD that's a very elegant solution. That is not necessarily true for all Cinder back ends. So for example if you're using the standard LVM backed ice guzzie of Cinder backend that is significantly more involved because then you do have local state that you do need to failover. But for CEPH RBD that's actually really nice and elegant combination that fails over very cleanly and very nicely. So this was the second layer block storage. The next layer is network. So let's have a look at this. Report the services on pacemaker 2 because it's very good and pacemaker monitor it and when the service crashed pacemaker moved it automatically so we must do nothing. The quantum DHCP agent is configured in active active mode. So the you must set a parameter in the quantum server and this is very good. The L3 agent is in active backup mode because we have trouble in grizzly release to run this on multi host in active active mode. So it's running on one server and when it's crashed it's crashed it moved to the other. The open V-switch agent you can run in active active mode. So a few additional words about the then quantum now neutron open V-switch plugin agent. What pixel park is using in this configuration is the OBS plugin in GRE tunnel mode. So in other words the reason or the consequence of this being all in active active mode is we permanently have these tunnels established between all of the compute nodes and the network node. So in effect it's one gigantic virtual switch or actually one gigantic virtual switch per tenant that we can then just plug VMs into. That is an infrastructure that basically lives all the time. When a compute node happens to crash and we need to bring up the specific or a specific set of guests on a different node which is what we're going to talk to in about in just a second. That compute node has access to the same virtual switch i.e. the same set of GRE tunnels and all of that is managed very nicely and automatically by the quantum open V-switch plugin agent or as it would be called in the present Havana release the neutron open V-switch plugin agent. So this is the third layer, the network layer. The next layer is services and APIs. So we put it in pacemaker 2 because it's very good and we the services are distributed. So horizon is running on control node 1, quantum server on control 2 and something like this. And the important is that we put my SQL and Revit MQ in DRBD. So you have one primary DRBD mounted on for example control node 1. And the second one is in secondary state. So the primary is in secondary state and the primary is in the data to the primary. And when one service crashed like my SQL pacemaker move the services the IP from my SQL mount the DRBD and start the my SQL service on the other node. One thing that applies here is there's more than one way to do it. You don't necessarily need to do this with DRBD. Another option would have been to use another separate RBD volume out of the CEP cluster. And another option would also have been to use replication facilities built into the applications themselves. My SQL, the my SQL database engine offers Galera which uses right set replication in a multi-master node between multiple nodes. In on the Revit MQ side there we could have been using mirror cues in Revit MQ. DRBD was chosen here for reasons of simplicity and stability but not necessarily because it is the one true option that you can use to deploy here. Like I said there is more than one way to do this. Another thing that should be mentioned is that most of these services can be run in both an active passive and an active configuration. So for example the Nova and Quantum API services would be classic examples of services that can run in multiple instances on multiple nodes. The nice thing about the pacemaker cluster stack is it enables us to do that very nicely as well. In pacemaker we can define a cluster resource as what is called the clone and in that we can essentially say give me four instances of Nova API. I don't care on which of the nodes in this set of say for example eight nodes you run them but give me four instances of them. So we can use pacemaker features here for both classic failover high availability and also for a certain amount of scale out. And then can that be combined with a load bound sort of like HAProxy or other things as well. So you see the pacemaker cluster with two nodes to keep Horizon Keystone, Glance, Nova, RabbitMQ, Quantum Server and the MySQL database always on. So this is the services on API layer. The next and last layer in our infrastructure is compute. So we use a pacemaker cluster and the special thing is that the instances are running in the self cluster. So we mounted you over over RBD under the standard default pass while live Nova instances and we create our own pool in the self cluster. So you should don't use a two large pool like five terabytes or something like this. I don't know why but it is better to use a smaller because the fried and IO process are not good in our environment. And that it is fast you will re-need six one gigabyte ports in trunk mode. Again, here the same thing applies that I said earlier. There is more than one way to do it. What anyone that is familiar with Nova realizes from this immediately is that because the stuff that normally holds the ephemeral data, the throwaway data for virtual machines is itself on persistent storage. There is no such thing as ephemeral storage. Everything by default is persistent. You could also employ a strategy where you say by default everything is not persistent and when you want a whole virtual machine to be persistent you have to boot off of a Cinder volume that is perfectly supported in Nova. And one other thing that you may be wondering about is why use an RBD mount of our live Nova instances that you then have to put under pacemaker management and things like that when you could just use the set file system and mount everything directly. Again that is a trade off in terms of stability. The set file system is considered experimental at this point. The downside of actually mounting an RBD with two and that is available to multiple compute nodes is you have to use some sort of high availability manager to do that. In pixel part case that HA manager is already there and it is just an additional resource that you plug into it. So that makes it very simple. An alternative case for using exactly this thing is Sebastien. Could you please raise your hand real quick? Sebastien An who is in the fifth row here has written a very interesting blog post on how to do this with Cephavest. So that is another alternative approach to doing that. So this is our full HA open stack. And the last thing that I will say is how did open stack affect our organization? Let me just quickly add one more thing. What this actually means just in case it is not 100% clear is that you can actually kill a compute node and the virtual machines will come up on a backup compute node, on a secondary compute node. So you have actually got your fully persistent highly available virtual machines. Which is something that unfortunately you can't really do with onboard components in open stack. So it is not something that is actually built into Nova itself, but it is something that you can build using a high availability manager that interacts with open stack. So in this case you can actually kill a compute node and the virtual machines that are on that compute node will all fail over to another one and will continue to live there and be available for you, which is kind of like what you want in a data center infrastructure. So the question was, is that four separate two node pacemaker clusters? Yes, it is separate pairs. But with the option of obviously, for example, the compute cluster you can easily extend. But yeah, you get the idea. I mean, Tim works on this stuff, so he gets the idea anyway, but that was just a rhetorical figure of speech. We had another question back here. Okay, yes, the question was, if you kill a compute node and you bring a compute node back up, someone has to take care of starting the virtual machines on that node. Nova actually does take care of that. We have a Nova option that is called resume guest state on host boot, which means you bring up the host. It will then check in the database, okay, which are the machines that are supposed to be running on that node, and check that against the local LibBird state and whatever is not running will get fired up. And the only little trick that you need to play is you need to override the host name that goes into the Nova database with an opaque host name. And for that, you have the host parameter in Nova.com. So that's the whole trickery around that. So how did this, our organization, to implementing an OpenStack environment is a challenge. And it's a very good way to get training before you install OpenStack and get support when you have a live environment. So now we enter quality, we work efficiently. We have a programmable infrastructure. And this creates a basic for further iteration because we can test software or infrastructure in OpenStack in minutes and then we destroy it. And we are ready for up and coming technologies. And now we sponsor an OpenStack user group. And the important thing for operators, it makes a lot of fun to work with it. And I had a lot of fun. I and my team had a lot of fun working with these guys as well because they were really, really sharp and nice to work with. If you have further questions, you can, of course, ask them immediately after. But I realize that there is apparently, according to rumors, there's people with beers waiting outside. But by all means, if you do have questions, get in touch. Basi's email address is right there. Mine is at the bottom. It's very simple. First name, last name, at company.com. So Sebastian.cachel.pixlapark.com. And mine is Florian.Hoss at hastexo.com. You can also find our company websites, obviously, at pixlapark.com and hastexo.com. And you can also find us on Google Plus and you can find us on Twitter and wherever. And you can find us, obviously, in the attendee directory for this conference. And with that, we will be happy to take your questions. But before that, let us quickly say, thank you. Thank you.


Eric, the Bitcoin price remained quite stable in the last 24 hours. Are there any specific movements that you would like to point out? Maybe what are the main support and resistance levels? And if you consider that we are still in an upward trend? So Bitcoin actually did something pretty significant last night with closing the weekly. We closed above a level that we haven't closed above in well over a year. So if you remember back on over here from February of 2018, Bitcoin got a pretty nasty bull trap in this area just about a year and a half ago. And to get back above it, to actually close our first weekly above it for the first time in literally a year and a half is quite significant to me as this was a trappy area. So there's multiple things going on here. Usually when you see an area like this kind of get special attention, it's because we're looking at institutional order flow dynamics at play. You see a big player is essentially presenting the illusion of a massive breakout right over here to the upside. What does it end up turning into? A trap. So that tells us that going forward here, this is going to be a massive pivot on price action. You can see it still gets respected in our more current times, just about a month ago in July. And then once again, just as of yesterday, we actually closed above this region. So to me, that does indicate that longer term, the trajectory is still to the upside. Looking for this to trend to the upside, timing of this sort of thing is always going to be variable. I'm not, I don't feel too confident on talking on something like that. But overall, I do believe that we're seeing constructive behavior, which is going to lead on to higher prices over these next few months. Bitcoin experienced sudden drop on Saturday, which brought it down $400 in just a few minutes. So what do you think could be the cause of such an abrupt drop? And don't you think that could be involving some big whale, so a big owner of a big quantity of Bitcoin? Yeah. I mean, it's definitely possible. The thing is, you know, when we see a drop like that on the weekend, weekend players or sorry, weekend plays typically just involve less amount of people in the market. So there's lower liquidity, so you can force these sorts of movements a lot easier. It doesn't take as much capital to wash some people out. And with Bitcoin's posturing overall on the higher time frames, I'd imagine that bigger players are probably trying to run out the overleveraged people with that nice little move to the downside. Now, of course, there were some formations in play as well. We had a symmetrical triangle that we broke to the downside, which actually hit one to one and some other technicals at plays that were suggesting a move down there. But at the end of the day, what really happened with the move? Well, the only answer that I can ever give ever is, and it's a boring answer, but it's true, there's more sellers than buyers. It wasn't one single person, maybe, maybe not. We'll never know. So it doesn't really matter if we know or not. The trading is the same, right? The only thing that we can kind of standardize in understanding of price action is by quite literally just looking at the footprints in price action, not necessarily diving into perhaps subjective reasons why people may or may not be selling at a price like that. But if I had to do a little bit of mental masturbation with it, I would say probably someone wanted to wash some overleveraged people out and looking at the higher time frames, looking at the general trajectory of Bitcoin, they're probably preparing for counter-trend moves, essentially based off that. Can you tell us a bit more about altcoins now? So there are any other altcoins displaying interesting performances that you would like to talk about? Yeah, so a lot of altcoins bounce recently. I'm going to be looking at the Bitcoin dominance chart right here. So this is essentially charting Bitcoin's market cap versus all of the altcoins in this market. And just like Bitcoin's price, the trend has been extremely strong with the upside. While we did find a little bit of a top right here, these are the simple and 200 expansion movement averages right here. I do think that this is massively bullish over a long period of time. Looking at our higher time frames like a monthly, yes, we just heard our first resistance, but do I think this continues on over time? Yes, I do. I'd be super bullish on this. So while I do think that a lot of alts actually do look interesting here, they're going to probably pop up a little bit more as this comes down off this first major top, I'd say longer term. Do I think that it's still interesting? Not so much. I mean, even just looking across the board, we're actually seeing something very, very, very, very unique right now in this market. Very rarely do we see altcoins and Bitcoin go in different directions versus US dollar versus Satoshi's. Yeah, absolutely. That's how it's designed, but versus US dollar, very rarely do we see the market kind of bifurcate like that. Usually everything kind of moves with each other. And right now, we see Bitcoin kind of in a more bullish posturing, but looking at all the top altcoins, I don't see anything that I really like. I mean, just, for example, right here, Ethereum looks very sick. Looking at Litecoin, Litecoin looks very sick. I mean, these are not good setups right here. In the past, though, we very rarely see the markets actually bifurcate. So I do have a little bit of difficult time saying that altcoins are going to go down while Bitcoin goes up. We just very rarely see that. But I would say that if Bitcoin is going to break to the upside here, if Bitcoin is really going to get that fall through that we were speaking about earlier, that's likely going to pass on through to the altcoins, which is going to affect them doubly. As they're kind of like an emotional little brother in a sense, playing out those moves more aggressively. So I would say that looking at Bitcoin, or sorry, looking at the general altcoin sphere, kind of like the gist of what I'm saying is if we're looking at them versus Satoshi's, probably going to bounce a little bit here. I think that the bounces get extended a little bit more. But longer term, I would be actually looking for those get faded on most of them. Of course, there's some stronger ones here and there. I think the ones that stand out are the ones that have been rallying for the past year. Contra to the general market direction, which is very impressive when they're rallying with Bitcoin versus Satoshi's, something like Chainlink, I believe, had a good chart. I think Ren kind of stood out. Ren BTC, whatever that is, people ask about it a lot. And there's a couple other ones. Maybe it's Mona. No, I'm probably not recalling it perfectly. But there's been a couple ones. Basically, the general gist is if your altcoin has been rallying for the past year or any time during the past year with Bitcoin versus Satoshi's, that's probably a good sign. And those probably are going to be the beneficiaries of any sort of a major reprieve here when we're looking at the Bitcoin dominance chart, starting to fall back a little bit. Another question would be related to Goldman Sachs, which lately issued a report, an analysis about Bitcoin price. They seem to be quite bullish. They said that the short-term target for Bitcoin now is like 13,971 dollars. And that investors should buy in the current situation during dips, as long as we don't trace lower than 9,084 dollars. So I would like to ask you, do you agree with this analysis? And whether you think that Goldman Sachs, being a big institutional investor, making this kind of prediction, can have any impact or implication for the price and in general for the industry? Okay, yeah. So Goldman Sachs coming out and saying something like this is a big deal. Actually, they are one of the more reputable players in this game. And from my experience in traditional markets, when Goldman Sachs says something like that, it typically does hold some weight. Do I agree with their analysis overall? I mean, I suppose that we would both be generally bullish over the long term is what it kind of sounds like they're getting out. Would I agree with their targets? To the downside, I would disagree. I think that Bitcoin loses its bullish composure anywhere below. 10-2 would be a massive blow if we took that out to the downside. And then 9,500 would be, I would be looking for a significantly lower price if that were to happen. So I don't really see where they're getting 9,000 from. But overall, I do agree with them. And I would say that is it a good thing that Goldman Sachs is getting into the game like this?  And then things get kind of faded over time. And usually you see that expectation get faded over the medium term if you want to call it that like the next couple of weeks perhaps. And then longer term actually a lot of the time they have been right to be fair.