The Blog of Harald

Jeremy Zawodny’s blog: High Availability is NOT Cheap

bq. The system will fail at some point, no matter what, even if it’s only for a few seconds. That’s reality.

Well said, bro. The context was discussions on the MySQL mailing list, but it applies to my areas of expertise (networks and security) just as easily.

Networks are fun because they can fail in surprising ways. The most obvious example is an expensive, redundant network connection that, at some geographic location, shares the same copper or fibre bundle as its primary. The backhoe takes them both at the same time! There are many less obvious failures, too. The host that starts transmitting garbage packets on a network; the network is still _up_, just unusable…

High Availability is not just expensive, it’s also _hard_…

There is a “Total Lunar Eclipse”:http://sunearth.gsfc.nasa.gov/eclipse/extra/TLE2003May15.html on Thursday night (May 15-16). It might be hard to see here in Toronto; the moon is a little low in the sky at this time of year. According to the “Lunar Eclipse Calculator”:http://aa.usno.navy.mil/data/docs/LunarEclipse.html the times and and sky coordinates here are:

| Event | Time | Azimuth | Altitude |
| Moonrise | 20:20 | 115.3 | —- |
| Sunset | 20:36 | —- | —- |
| Moon enters penumbra | 21:05.3 | 123.3 | 6.1 |
| Moon enters umbra | 22:02.7 | 134.2 | 13.6 |
| Moon enters totality | 23:13.7 | 149.3 | 21.1 |
| Middle of eclipse | 23:40.1 | 155.5 | 23.1 |
| Moon leaves totality | 00:06.4 | 161.8 | 24.7 |
| Moon leaves umbra | 01:17.4 | 179.8 | 26.4 |
| Moon leaves penumbra | 02:14.8 | 194.3 | 25.0 |
| Sunrise | 05:51 | —- | —- |
| Moonset | 06:08 | 241.7 | —- |

Next one is in November, so will be much higher in the sky…

“blog.org”:http://blog.org/archives/cat_useful_web_resources.html#000716 → “Playing with Time”:http://www.playingwithtime.org/ :

bq. “Playing With Time”:http://www.playingwithtime.org/ is an exciting, new project that looks at how the world around you is changing over many different time periods.

bq. Here at the “Playing With Time”:http://www.playingwithtime.org/ web site, unseen worlds of change will be revealed. You will see time sped up and slowed down, and behold the beauty of change.

I have always been intrigued by visualisation techniques; manipulating time is another one. Taking ordinary events and speeding them up or slowing them down often reveals existing patterns that we cannot normally perceive.

“Playing With Time”:http://www.playingwithtime.org/ has both fast motion and slow motion movie clips revealing a variety of changes. I particularly like the shots of the same location on several different time scales; you can watch the clouds move over a period of minutes, or see the tide roll out, or see the grass grow and die over a year. Fabulous stuff, and worth a visit.

Robert L. Park has written The Seven Warning Signs of Bogus Science:

bq. I began this list of warning signs to help federal judges detect scientific nonsense. But as I finished the list, I realized that in our increasingly technological society, spotting voodoo science is a skill that every citizen should develop.

The list:

# The discoverer pitches the claim directly to the media.
# The discoverer says that a powerful establishment is trying to suppress his or her work.
# The scientific effect involved is always at the very limit of detection.
# Evidence for a discovery is anecdotal.
# The discoverer says a belief is credible because it has endured for centuries.
# The discoverer has worked in isolation.
# The discoverer must propose new laws of nature to explain an observation.

From a New Scientist article:

bq. Buildings of the future could be “clothed” in a flexible, power-generating material that looks like denim. The Canadian company developing the material says it can be draped over just about any shape – greatly expanding the number of places where solar power can be generated.

Cool; another Canadian company working on alternative power systems. This particular material has about the same efficieny as regular solar panels. However, it apparently looks something like denim, which makes for _interesting_ building designs…

ACPI and FreeBSD – looks like the newly released version of FreeBSD is the first major UNIX distribution to support ACPI hibernate. Cool; I’ve only had an ACPI laptop for two years…

Right now I run Windows 2000 on my laptop, and run RedHat Linux (under VMware); all this so that I can run my unix-based e-mail software in a portable, hibernatable environment. I’d like to simplify a bit.

the Linux 2.5 kernel has ACPI support (they apparently had to do a major rewrite of the driver architecture to support it), but 2.5 isn’t stable enough for my purposes yet.

So, maybe my next block of “play around with the computer” spare time will go to a FreeBSD install…

On the other hand, while writing this article, I discovered swsusp, a program that lets you do suspend-to-disk without BIOS support. Time to check that out too.

We’re just 12 years away, but I’m reasonably sure that hovercars aren’t going to be an option, nor will 512K Macs sit in antique store windows. 2015 will look like 1990, because you can’t photograph wireless networks. The best part of the future is always invisible.

From a brief discussion of Back to the Future II by James Lileks. I found it via the Quote of the Day mailing list.

Visit the site and build The best paper airplane in the world!.

This is similar to a design I used to fly as a kid, and that one worked very well. This one adds a few extra folds to move the center of gravity low and forward, which improves stability and hang time.

Apple – PowerBook G4 17″

1″ thick, 6.8lbs, 1Ghz G4, 512Mb, 17″ display @ 1440×900, 60Gb drive, slot-load DVD-writer, GeForce4 440, gigabit ethernet, 54Mbps wireless network, Bluetooth, FireWire 800, 4.5 hours battery life… And it runs MacOS X, the FreeBSD/Mac hybrid OS that is apparently a UNIX geek’s wet dream.

I think putting Gb ethernet on a laptop is ridiculous; ISPs and large corporations are starting to use Gb ethernet for backbones and interconnects; it’s wasted on a laptop. Still, a machine to drool over, and only $3299 (US).

Atmospheric a-bomb testing comes back to haunt us. An article in New Scientist describes high levels of radioactive material in sea-bird guano, particularly uranium-238, radium-226, and cesium-137, the last of which does not occur naturally.

Particularly in the arctic, plants eat guano; animals eat plants; humans eat animals; all the while, radioactivity accumulates.

Someday we’ll wake up and realize we have to *live* in our own shit; we can’t just get rid of it. Hopefully that day won’t come too late…

Finally, some reseachers have shown that those ickly overhead flourescent lights really do cause eyestrain in computer users. An article in Realage’s HealthBytes Newsletter, claims

a significant decrease in eyestrain, eye fatigue, sensitivity to light, blur with computer use, and glare or reflections from the computer screen

when overhead flourescents were fitted with an acrylic filter tinted to give off “more natural light”.

Ye gods, I despise overhead flourescents. I’m glad to see more concrete research in this area…

According to this article in New Scientist, China will attempt to launch a manned spacecraft in the second half of 2003. They’ve already successfully launched four fully functional, but unmanned, capsules.

It’ll be nice to have some competition again; maybe that’ll push the US space program out of the doldrums…