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VDSL2, Start time, HDD Reliability, stdio, Boom, HAWC, MAD, Movies SD cards, CAP

posted Mar 4, 2017, 10:38 PM by Sami Lehtinen   [ updated Mar 4, 2017, 10:38 PM ]
  • I just can't stop hating VDSL2 tech. Now the speed which dropped drastically have returned to normal, without any known reason. Well, I'm glad that it happened, but it's still very annoying that performance can drop by 35% without any known reason and then suddenly return to normal levels, or even get better. I assume there has been some changes to the signal path. But it's very hard to confirm.
  • Wondering why so many projects focus on application start time. Firefox 50 advertises greatly improved start time. But Browser is just like some other apps, it gets started once, and is kept running all the time. Based on this application start up time isn't that kind of extremely important factor. This is just my personal option.
  • Hard Drive Stats for Q3 2016: Less is More. I've got nothing to add to this post, great stuff.
  • So tired of administrators who do not understand at all stdout and stderr. Sigh, sigh and sigh. Because they don't bother to check those, then they claim that it's impossible to figure what's out. Well, let's then agree it doesn't work and that's life. It's easier for all of us. This has been a problem for along time, but there's just more and more totally and absolutely clueless system administrators out there.
  • It's funny how far part "nice to have" and "actually required" feature requests can be. When someone needs to pay for that nice to have, then requirements are quickly trimmed down back to actually required level.
  • Drones do present objective security threat? - I guess nobody can deny that drones are dangerous.
  • Read a few articles about Boom. Interesting. But I'm highly skeptic. I've seen just so many supersonic passenger jet projects to fail in way or another. Actually this Boom project isn't new one, it's been lingering around for over an year. But it it would turn out to be practical and working project, really entering commercial service with the prices they're now advertising it would be truly awesome.
  • Hypersonic Air-breathing Weapon Concept (HAWC) is something quite similar to "boost-glide" project. We're seeing interesting times with these new weapon systems.
  • Read The Economist Special Report Espionage issue. Some charts about what's being unacceptable and acceptable were really interesting. What does it matter if governments are watching you, if you've got nothing to hide. I do value privacy, but I still don't have anything to hide. Most of my friends agree on this. So government spying isn't that bad after all, even if it would be foreign government. It's hard to decide what's right and what's wrong in this kind of situation, because it's based on so many different factors. Who's watching the watchers? Main problem is that individuals or groups, other powerful entities could abuse the data.
  • Hunting submarines with Magnetic Anomaly Detector (MAD) - Not forgetting Debye effect, hydrodynamics and Superconducting Quantum Interference Devices (SQUIDS).
  • Watched Snowden (2016) movie. "Many people cruise through life happily, why can't I?" - That's a very good question. Thinking too much, doesn't seem to be a good idea at all. It would be much easier just go with the flow and not caring about anything at all. Just be, here, right now, and enjoy? - Sounds like a easy thing to do, right? - Actually where he copied files the copying speed of 1,37 or 1.12 MB/s seems very high to me. Because many SD cards / flash storages perform VERY or lets say extremely badly when you've got multiple parallel write streams going on. Most of storage is optimized for concurrent large writes, like single video stream being stored. It would make much more sense to first zip the junk and then copy single zip. Copying multiple files in parallel is very poor strategy. I wouldn't recommend using that.
  • Julia Evans wrote about critique of the CAP theorem. Well in many systems there are requirements for several different operation modes and styles inside the application. Which can be provided as layers. So CAP theorem is just theorem, reality is completely different show and can be much more complex. But this shouldn't be anything new to anyone. We we think about credit cards, some transactions are authorized and others aren't. Which allows 'same system' to provide consistent (linearizable) and totally independent high availability transactions based on the sum of the transaction and multiple other factors. This is quite common, and I've written several times about these things in my blog. Just like how do you deal with strong transactions and simple RESTful API etc. Do you use locks or some other approach which allows more freedom. Mixing these alternatives allows you to provide high availability and performance, and only trim it down in situations where it's absolutely quired. Like in case of ticket booking and so on.