Upgrade, Downtime

Today, the computers I name ‘Phoenix’ and ‘Klystron’ received major updates to their core ‘libgcc’ and ‘libstdc++’ libraries, as part of a combination of 25 actually-updated packages. Even though this did not upgrade the (Linux) Debian version of either O/S, which is still ‘8.10’ , This type of an upgrade requires a reboot. So I rebooted.

But, The PC which I name ‘Phoenix’ is also my Web-server. Therefore, there is no way for my blog or site to be visible to the Internet, during a reboot. My blog was offline from 20h15 until 20h25.

I apologize for any inconvenience this might have been to my readers.

Dirk

 

Freezing Rain This Evening, Power Failure, Downtime.

I take the unusual measure of hosting my site, and therefore also this blog, on the home computer I name ‘Phoenix’, rather than on a professional Web-hosting service, the latter of which is what most people would use.

This has as unfortunate side-effect, that the visibility of my site is only about as good, as the up-time of the home-PC in question. Therefore, if there is a power-failure, the site will go offline. Even though one of the plug-ins I have installed on my WordPress platform is, to display a Maintenance Mode Page if I so choose, the visibility of such a maintenance-mode page would still depend on the software running, that is my Apache Web-server, as well as on this computer being connected to the WAN – In other words, such a maintenance-mode page will not be visible during an actual power failure, only if I decide to tinker with my blog, and if the server itself is still up while I’m doing so.

Later this afternoon (on 1/23/2018), we were experiencing sheets of freezing rain, and so predictably, the power went out around 17h40. But, just as Hydro-Quebec had predicted, they were able to restore power to my home, by 20h30 the same evening. Gosh knows what had gone wrong, but the utility was able to repair it very quickly, given the circumstances.

And so until about 20h50, this blog and site would not have been visible. I apologize for any inconvenience to potential readers.

Dirk

(Edit 1/24/2018 : )

As it happens, my power failed again, around 22h40 the same evening, but only for about 5 minutes. However, this time, I did not restart the computer immediately after the second power-failure, instead deciding to wait until 6h50 this morning to do so. So again, the blog was offline until 6h50 this morning.

 

Kernel Update Today, Downtime

A fact about mys site which some people may not know, is that I take the unusual approach of hosting it on one of my PCs at home. The computer which acts as my Web-server, is also the one I named ‘Phoenix’, and which is still running Debian / Jessie. What this piece of trivia means in practice, is that any downtime of this one PC, also causes the site not to be accessible on the Internet. This is very different from how it would be, if I was to pay a professional hosting service.

Today, ‘Phoenix’ received a long-awaited kernel update, With which the package maintainers hope to be mitigating the ‘Meltdown’ vulnerability. What this does, is complete the work that some of the System Programmers have been doing, on the ‘Meltdown’ vulnerability, since as it stands, all the kernels on the list here have been patched now.

The fact is somewhat ironic, that ‘Phoenix’ has an AMD processor, and was therefore never directly susceptible to this form of attack. However, the computer which I name ‘Plato’ has an Intel CPU, and received its kernel update on January 5.

I congratulate the kernel-programmers on a milestone in their work.

Now an unanswered question remains, as to what will be done – if anything – about ‘Spectre’, which is a related vulnerability, in which a hypothetical attacker would ‘attack’ other processes running on the same machine, but not the kernel. The problem with ‘Spectre’, as far as I think I understand it, is that it involves “Speculative Execution” of code, but does not involve ‘system calls’ per se. What that means is that, unless somebody comes up with something brilliant, the only ways to patch that would either be to disable Speculative Execution entirely, or, switch to new chips, which have been designed with ‘Spectre’ taken into account, but which haven’t been designed yet in fact.

‘Spectre’ may also affect some AMD CPUs.

In any case, my site was unavailable from about 15h30 until 15h45.

Dirk