When the internet crashes

.. no one will be able to tell you why.  This didn’t make it into my adventures in hell page, but it’s typical.  A few days ago, logging into my web site’s shell account suddenly acquired a 2 minute lag between password and prompt.   As this was extremely annoying, I started collecting relevant data and  complaining to the site’s technical staff.   No one had any explanation, or infomation about why there was suddenly a delay, but the curious fact I turned up was that only some points of origin were affected.    After about 12 hours, the problem, whatever it was, went away.

This kind of network glitch seems to happen to me every year or so. It’s never the same strangeness twice, and threre’s never any explanation.  No doubt, something, somewhere was broken, and someone who was affected by the broken hardware or software eventually noticed, and fixed it.   Meantime, at least one of the victims is left with no information, no tools, and no recourse.

This general pattern is common to essentially all software driven activity.  If it works, great.  If it doesn’t, you’re pretty much up a creek without a paddle.   So one day if you wake up and find every channel dark, you’ll know why.  I just told you.

The language “C” and the perfectability of software.

An interesting software event occurred today: I fixed a bug in a “C” program, which I have known must exist for about 10 years. During those years, I’ve made several concerted attempts to find this particular bug, but I never could pin it down. It was a rare glitch in a system with many major glitches, so fixing it was only a quixotic quest for perfection, not a necessity. I finally stumbled into a repeatable test case while debugging some newer code.

What has this got to do with “C”? The bug was a simple fencepost error, where a buffer was overrun by 1 byte. This could have been detected automatically, and would have been in some more modern languages. It’s not clear that this could have been detected by anything other than a permanent runtime system which always checks – a specialize test environment might have run for years without producing the right kind of input data.

I worry about the uncountable millions of lines of “C” code that run everything from my desktop computer to the planes I fly in. They can’t really be replaced or rewritten. “C” is an easy target because it’s such a wonderful language for producing buggy code.
My top ten list of way to be screwed by “C”

This happened to be a type of problem that could have been detected automatically. There are plenty of other bugs that can’t be found that way, or by any known method. In some sense, the worst bugs are the ones you don’t know exist until you see a result you don’t like. There’s no way to avoid those.

Digital Frames

Digital frames started out a few years ago as expensive novelties, but the prices have plummeted and I’ve joined the movement. I place mine on my desktop, within arm’s reach but not in the direct line of sight. I like mine so much I’ve bought more and given them away as gifts.

So far I’ve bought four different frames from different manufacturers. They’re not quite idiot proof yet, but anyone advanced enough to photoshop his own digital photographs will have no problem getting them loaded and running. The hardware is pretty solid and standardized – basically a small LCD, USB interface, some amount of internal memory, slots that accept most of the common camera memory cards, and of course, a power brick. Some have WI-Fi. Some have remote controls. It all works.

The on-board software is pretty awful now, but is bound to improve. Part of the problem is the no computer required requirement, which currently also means your computer is irrelevant. Everything about what the frame actually does is controlled by pushing combinations of buttons to scroll through multiple levels of menus. Yuck. Other things are just inexplicably dumb:

• The “random” slide show always starts with the same picture. Sure, it seems to diverge eventually, but some photos are seen much more often than they should be.
• There is a low, unpublished, absolute limit on the number of different photos that will cycle through the slide show. Each model seems to have it’s own limit, and none advertises what their’s is; but don’t bother cramming all 20,000 of your digital pictures onto one card. For now.
• Frames accept and store huge images in their internal memory, although they can only display limited scaled down versions.

The software can only get better.

I predict that the days of the traditional photo-of-wife-and-kids on the desktop are numbered. The photo-on-the-wall may follow soon. It’s a mystery to me why my expensive flat panel TV can’t double as a digital frame already.

Carbonite

Carbonite is an offsite backup product with a general philosophy of install it and forget it. The short form review is that it probably works well enough for general consumer use. It seems well written, it’s extremely simple to use, and the customer support crew is very reactive and keyed into the difficulties that joe-average user might have.

On the other hand, it doesn’t seem to be engineered for large file systems. The first sign of this was when Carbonite announced it was “done, you’re all backed up!” after only a few hours and a few gigabytes of data. It turned out to have only backed up the “documents and settings” folder. I pointed it at my real data (images, mp3s, cvs repository, source code) and it seemed to be chugging along, so far so good.

After a while I noticed Carbonite doing complete file system scans, which severely degraded my system’s performance, and due to its “no options” philosophy there is no way to slow down or schedule them. Also viewing the backed-up file database (presented as a pseudo disk drive) is extremely slow. I think the algorithms being employed just didn’t envision file systems with 200,000 files in the backup area. This is probably fixable, but until It’s fixed I can’t have Carbonite around.

Note the date of this review and your current calendar. Carbonite is a promising product, just not ready for my kind of user yet.