Why I Am Happy, that my Computers Are Working Again

The recent power failures left me in quite a state of distress, not knowing what the fate of my computers would be.

The computer acting as my Web server, ‘Phoenix’ is a Linux computer, running a “Debian” version of Linux, and a flavor of that, which is “Kanotix / Spitfire” . After the second power interruption this morning, ‘Phoenix’ was actually easier to restart fully, than my Windows 7 machine ‘Mithral’ was. This was somewhat reassuring, since ‘Mithral’ has stronger hardware, and since If the software on ‘Mithral’ was ever permanently messed up, I could in fact try to resurrect it by installing Linux on it. It seems that Linux was after all more stable than Windows.

But what happened to ‘Phoenix’ was also better than a scenario would have been, which I had running through my head between 7h30 this morning and 12h00, the time at which I got ‘Phoenix’ running again.

I had had the scenario in my head, that ‘Phoenix’ could have started to perform an ‘unattended upgrade’, at the moment the power went off, a coincidence which I would have been unaware of.

Luckily, this was not what happened.

But had this happened, my own version of what would have gone wrong differs slightly from the official version, according to which the package manager would simply have gotten jammed in some locked state.

There happen to be other power-users, who complain on the Kanotix user forum, that they had been running a lengthy upgrade while their power was strangely cut. Those people ask for Expert support in unjamming their package manager, which more detached people on the forum give advice on how to do.

According to me, they had such a hard time unjamming their package manager, because this is not all that was wrong with their computers. According to me, those users suffered from two problems at once: A jammed package manager, plus A corrupted file system.

I had a vision of having to approach the Kanotix user forum with the familiar line, ‘An upgrade was running, when the plug was pulled.’ But luckily, no upgrade was running at that time…

…And, there is a specific reason why No Unattended Upgrades Were Running. After I rebooted ‘Phoenix’ successfully, I performed the upgrades manually, which were to have run, just to confirm that my package manager still works 100% .

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Again, my blog went down due to a power failure.

Yesterday, on the Island Of Montreal, we were experiencing some extreme weather. And, I host my blog on my own, private computer, acting as server. Due to the power failure which already took place last night, my blog went down then. And I wrote about this in this previous blog posting.

That event left many tree branches hanging in the power lines, which stayed there overnight. But alas, this morning, my power failed again around 6h45. And then, to aggravate my nerves, the power came on again for two seconds around 7h00, after which it promptly went off again. And the power came on for another two seconds, around 7h15, after which it went off again.

Naturally, in this situation I could not assume, that even if the power would have come on again at let us say 7h30, it would have stayed on. And so I did not restart my server this morning.

Presumably, the Hydro-Quebec crews have cleared the branches from the power lines by now, without electrocuting their workers.

But this blog would only have started to become visible again, around 12h00 or so today.

I apologize for any confusion this might have caused.



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My blog was down tonight due to a power failure.

This blog is being hosted privately, on my own computer, acting as server. And for this reason, it is sensitive to such factors as power failures. I do not have a backup server, nor a UPS, the way hosting services would have.

In Montreal, we have been having difficult weather, with sleet turning into genuine freezing rain. As a result, a power failure did hit me at 22h40 this evening. The blog should have started to become accessible again after 23h40.

The actual power failure only lasted for 10 minutes, from 22h40 to 22h50. But I only restart my computers after I am convinced that consecutive p0ower failures are unlikely. And during the coming day, on February 25, additional power failures are possible, because while the freezing rain is officially over, wind gusts up to 60 km/H are forecast.

Thank you for understanding.



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Recognizing that Methodologies Exist, to Computerize Volumes of Text

One feat of Computer Programming which is not in itself forbidden, is to store text in a database, formatted as HTML. But an aspect of this which needs to be recognized, is that random text such as ‘blog entries’, tends to be of variable length, while database records still tend to be of fixed length today.

But, methodologies have existed in Computer Science for a long time, to manage variable-length data. One such methodology involves ‘linked lists’, and another involves ‘doubly-linked lists’. This is commonplace with pointers and memory addresses, but can easily be translated into records with record numbers.

Hence, random text can be subdivided into smaller blocks of arbitrary length, and a table of database records can be defined, such that each record has a numeric field, another numeric field, and then the text field corresponding to a block. Because each record in the DB table has a record number intrinsically, the first numeric field within the record can point to another logical ‘next record’, while the second numeric field to a logical ‘previous record’, just as it was taught with pointers. An impossible record number such as (-1) could be used to signal an end to these chains…

And while this sounds interesting in theory, one type of data processing which “WordPress” already seems to do well, is to keep track of ‘revisions’ that have taken place to a blog entry, each of which could have replaced, inserted or deleted a block of text…

Oh, the marvels of Computing…

I think one would also need to keep track, of the possibility that If a block of text had 256 characters by default, any one block could be using fewer than its full 256 characters…



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