Category Archives: Computers

Argh!

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All of a sudden my Treo 650 locks up hard when I try to enable Bluetooth. You have to do a hard reset (wiping all data) to get the phone feature to work again. I was able to back it up before doing this, but… What gives? I can live without Bluetooth, but I kind of like it, when, you know, all of the phone’s features work.

Steve, is this a sign?

Sit in the Corner

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I started a blog post about this, but it talked about terabytes NASs, HDTV DVRs, VoIP / SIP, LDAP, DNS caches, NTP strata, and a bunch of acronyms.

So instead I’ll be incredibly precise. This PC, seemingly sold only at Walmart, is really cool. It’s not that fast. Its specs are bad any way you look at them. Unless you look at power consumption. 20 Watts peak power, 2 Watts average. By comparison, my desktop machine has a 300 Watt power supply. For someone who wants to set up an always-on Linux server, this thing is screaming your name. I’m strongly attracted to the idea of setting this thing up with handful of 500 GB drives, to build a network fileserver with a terabyte or two of capacity. And doing software RAID across them. (I’m fairly certain that the hard drives would draw more power than the whole system… Although you could set up power-saving features, since a home fileserver could surely power down the drives periodically.)

There’s also a cheaper one that seems to be the same, except it comes with 512 MB RAM instead of a gig, and comes with gOS instead of Vista. I’m dying to play with OpenFiler, a Linux-based “appliance” software package for some superb fileserver tools.

Sheesh

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Now that Comcast has vowed to quit arbitrarily blocking services on their Internet service, they’ve decided to shift the degraded quality to their HD offerings. This article talks a bit about how Comcast is running some heavy compression to fit more HD channels into finite bandwidth, but it has lots of words. So check out some pictures of screen captures of identical footage from FiOS versus Comcast. Slashdot has the story here.

ShotSpotter

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Are you familiar with the Shotspotter system? I’d seen it on a National Geographic TV show, and remembered in the back of my head reading about it being deployed in parts of Boston. It’s actually very cool how it works — it essentially has a big array of microphones, and when it “hears” a gunshot, it’ll compare the exact time of arrival of the sound at each location to triangulate a position, which then pops up on a dispatcher’s screen.

So I’m listening to Boston PD on the radio, and maybe five minutes ago the dispatcher called out for a reading on the ShotSpotter system. “Five, six, seven, looks like eight shots fired.” She figured out the location from the map (apparently, an alley), and started a couple cars. In maybe 60 seconds an officer was on the scene, reported a car leaving, and had confirmed that shots were fired with a witness.

About a minute later, the dispatcher said that they had received a 911 call for shots fired from the same location. (Which means that they had an officer arriving on scene by the time the call came in!) They’ve just pulled over a possible suspect, and another officer found the shell casings. Detectives are en route now for forensics processing.

I’ve got to say, this seems like a pretty impressive system.

Write It Out

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I’ve seen this suggested before, but only half-believed it.

When you’re stumped by a question, write it out. We’re hosting a video game tournament tomorrow, and I was thinking about scoring. I got stumped by some technical problems with the way the bracket would work.

So I decided to burn my weekly Ask MetaFilter question. Except, three-quarters of the way through writing out the question (in great detail), I realized exactly how you solve the problem.

The thing is, if I sat here and tried sketching out how the bracketing would work, I never would gotten it. For some reason, writing it as a question caused me to be able to answer my own question, in a way that starting at it didn’t.

Seriously, try it next time you come across a tough question. It obviously doesn’t work 100% of the time (“How many escalators are in Wyoming?”) But something about writing it out causes the mind to look at it differently. And sometimes that’ll solve your problem!

Also, an Excel hint… How do you do “Best 2 out of 3?” in Excel? There’s no native function to do it. And if you asked me to write code, I’d overthink it and write some contrived thing that would take the best x of y items. But let’s say that cells A3, A4, and A5 (thus A3:A5) contain the three scores, and you want the best (highest) two of the three. =SUM(A3:A5) - MIN(A3:A5) does it. Best two out of three is the same as “All of them, discarding the lowest.” This doesn’t scale: if you wanted the best six out of eight, it’d be much harder to compute. But here, you’re just dropping the lowest.

XBox

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One thing I find interesting about technology is that sometimes a trivial technological thing has huge differences to the end user.

I’ve been playing Grand Theft Auto a bit in my spare time, on the Xbox 360. After re-arranging some things, I’ve run into a strange problem where, when I power it up, it loads older game files, not the newest. I know exactly what’s wrong, but it’s kind of like the “roger tone” to “FRS” leap–intuitively understanding what’s wrong here borders on savantism.

When I rearranged things, I didn’t bother to plug the Xbox back into my switch. I think the cable it was using is out in another room right now. So the Xbox has no Ethernet connection. Are you seeing why my game loads really old saved data yet? Hint: the game doesn’t use the network in any way, shape, or form.

The Xbox, when it’s connected to the Internet, will grab the correct time via the web. (I’ve wondered about this, actually: is it using NTP? Is it syncing to time.windows.com? I’ve been tempted to try packet sniffing, but it would basically require ARP poisoning, which I’m reluctant to do right now, as both the Xbox and my laptop are essentially on the school’s network, so it wouldn’t be too easy to “safely” do it.)

For some reason, though, when shut down, the Xbox never runs a “systohw” call (or at least, that’s what it is under UNIX) — the system clock, which was just synchronized and is quite accurate, is never written to the hardware clock. So two weeks ago, when I booted my Xbox, it was March 14, 2008. I saved a game, shut down the console, and went to bed. And then I rearranged stuff and realized that there was no reason for my Xbox to be online, so I moved the cable to the common room.

So the Xbox, now booting with no Internet connection, thinks it’s November of 2006, since the software clock never got committed to hardware. And the game, not anticipating bizarre things like this, automatically loads the game with the newest timestamp. As far as it’s concerned, the game I saved two weeks ago is a year and a half “newer” than what I saved earlier today.

So there you have it — whether I have an Ethernet cable hooked up or not changes the year on my Xbox, which causes it to load old games. And it’s all because the Xbox, for reasons I can’t understand, never writes the time to the hardware clock. (To me, this is a bug, and one that would require adding one line of code.) And it shows something neat (or scary, depending on your perspective) about programming — trivial details (like whether you sync the hardware clock to the software clock when you shut down) manifest in entirely unexpected ways, like which save file my video game opens.

Stopping Blogger Spam

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It’s very common for spammers to create blogs on Blogger (something.blogspot.com). There’s a survey out there that found that 74% of blogs on the site were spam.

It turns out that you can report spam blogs pretty easily on Blogger: they’ve got a form for it here. You won’t find it linked to on their site (or at least, I didn’t), but it’s available. Use it and make the Internet a better place!

Weird Spam

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I somehow came to read the “blog” of the Perl NOC one day–the network admins for the perl.org sites. They get some really amusing spam. And then there’s that category of things where you think it might be spam, but you’re not sure, like this one.

But anyway, today I was checking through my own mail that got filtered as spam, and got the following:

from    Selma Orr 
to  helen@n1zyy.com,
date    Wed, Mar 26, 2008 at 12:27 PM
subject I hate you damm

Instant delivery worldwide. Certified by VISA and VeriSign.

http://irisembreyck.blogspot.com

They spam me, tell me they hate me, curse at me, and then expect me to buy whatever they’re selling? Also, why does “helen@n1zyy.com” get a lot of spam? That address never existed! (I should disclaim that this message wasn’t actually sent to helen@n1zyy.com, otherwise I wouldn’t have gotten it. But I get rejected mail to helen@n1zyy.com showing up in the logfiles daily!)

Captchas

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For those not aware, “captcha” is the name given to the little images with distorted text. The premise is that a human can figure out what they say, but that a computerized “bot” cannot. Thus they’re used to keep people from writing scripts to sign up for hundreds of accounts, or to prevent spammers from leaving comments. (Incidentally, there are some clever ways to defeat captchas. The most creative was a group of people that apparently started a “free” porn site, where users only had to complete a captcha to sign up. Except that the captcha actually came from another site: they were essentially getting hundreds of porn-starved people to help them bulk-register for various accounts!)

Anyway, besides causing major problems for the visually-impaired, there’s another problem with captchas… Consider the one I got the first time I tried to sign up for Hulu:

Professionalism

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I frequent WebHostingTalk.com, a really good forum for people in the web hosting industry. There are lots of really knowledgeable people on there, but there are also sorts of people without so much technical knowledge….

There was one guy a while back who announced that he was starting a video sharing site (a la Youtube) and that he’d need 450 petabytes of transfer a month. No one was quite sure how to respond, since this is orders of magnitude more than anyone measures anything in. I calculated that he’d be using about 1,400 Gbps. (And that’s an average… Real traffic patterns for big sites are more of a sine wave, so you’d probably want about 2,000 Gbps aggregate capacity, which you’d be filling at peak hours.) I’m fairly certain that even a site like Google doesn’t use anything like that. In fact, I’m fairly certain that even if a site like Google called up their providers and asked for 1,400 Gbps, they’d be laughed at. No one out there can provide that.

But some are just distressing. One guy posted, maybe a year ago, that he was getting a “private room” and didn’t know what he’d need for equipment. Did he need a router? Switches? A “private room” in a data center, by the way, is to host your many racks of servers, walled off from others for maximum security. You’ve got to be a very big place, with a very big budget, to be doing that. This is kind of like asking, “I’m buying a 500,000 square foot warehouse. What do I need? Do I need a forklift? Lights?” (A lot of answers were basically, “What do you need? You need an IT department, and someone who doesn’t have to ask this question.” Although my favorite answer was, “Padded walls.” Normally it annoys me when people give rude answers online, but I couldn’t help but burst out laughing.)

Today’s post is from a guy who seems to have about 30 servers with one company, running what I can only assume is a successful hosting company. He’ll fill one server and order another, but he’s having difficulty “managing” the traffic–he wanted to pool all of the bandwidth together. This is something that most big companies will do for you if you ask, since you’re a huge customer and they know that their competitors will do it if they don’t.

If you buy a dedicated server, you’re usually given a bandwidth allocation in GB/month. I’m allowed 1,000 GB a month, for example. (And I don’t use 5% of it.) This comes out to using about 3 Mbps 24/7, but it’s much more convenient for me since I don’t have to worry about momentary usage, just the net amount of transfer moved. There are also subtleties here: I have 1,000 GB over a 10 Mbps line. 1,000 GB means that my average use can be up to 3 Mbps. But, in real life, as I mentioned, traffic patterns ebb and flow. If I were using 3 Mbps average (I’m not), I might be using 5 Mbps during the day, and 1 Mbps at night. So just giving me a 3 Mbps line wouldn’t cut it, since it’d be really crappy during the day.

But this guy’s host quoted him a price in Mbps. He was very confused by this. He was used to his GB/month, and didn’t know what to make of these foreign “Mbps” measurements.

Someone else just posted about how some guy with the IP 0.0.0.0 keeps connecting to him, and wondering if he should ban that IP, which he thinks is awfully suspicious. (It’s not as bad as the guy who was getting people with “blank IPs” connecting to him, and wondering if he could ban a null IP in his firewall… It turned out that he was running some random command which was returning way more than just IPs, hence a number of blank lines…)

Who are these people? I wouldn’t post a blog making fun of people who didn’t know otherwise obscure things, except that these should be basic little tasks for people in these positions. It’d be like a certified (not certifiable, but certified) sysadmin for Windows systems posting and saying, “I need to change my desktop background? How can I do this?” Or a car mechanic, who’s gone on and opened his third garage, posting and saying, “The oil in my car is old and dirty. Is it possible to somehow drain the old oil and put new oil in?” Or, for the more absurd requests we see, someone posting on a financial forum about how they’re starting a lemonade stand and think they need $750 billion in startup capital, wondering what bank will give them a better interest rate. It just shocks me that these people are successful and yet so clueless.