The tweak that broke

Yes, I had a little accident ;-P

With the increase in technology came an increase in what I'd like to do with that technology, specifically be able to offer secure (https://) connections for security purposes on some of the sites I host. And although there have been moves to make virtual hosting of port 443 secure sites possible, they rely on changes to browsers which — as we all know — are a bit like a brick swimming against the prevailing current. Instead, therefore, just as with the ten year old specification of IPv6, we are required to use one IP (v4) address for each secure connection we wish to enable. So I obtained an increase in my IP allocation from a /29 (five effective addresses) to a /28 (with thirteen). Plans were made for a nice, smooth transition using proper scheduling of DNS and MX record changes when … I accidentally pulled the power on the modem-router and the change happened instantly. Without any of the advance setup.

Needless to say I was grateful for being the only person around at that moment as the world was filled with my choice 'language' about the unfortunate event, and I set to in trying to recover the systems. And, for the most part, I got the connections working again within the hour save for waiting for DNS servers around the world to play catch-up.

But e-mail wasn't arriving. My (Zimbra-based) mail server cold send messages out fine, but nothing seemed to be coming inbound. Eventually this was traced to a configuration error with my carrier this afternoon and they reset their end of things. Great? Well, no actually. At this end I lost all connectivity entirely. The outside world could see my router, yet I couldn't get beyond it. Three hours later the software-hardware-firmware-network interactions were finally resolved, I'm happy to say, so now everything should by A1 Bristol fashion.

That three hours without any connection was a bit scary though …

Back on-line

Did you miss me?

Over the last few days I've been upgrading the server kit I use to run my websites and API services on. The main server moved up from a dual 2.4GHz Xeon to dual 2.8Ghx Xeons, and from 2Gb of RAM tripled to 6Gb. I think that should cope with almost anything that gets thrown at it. (It is presently running around 50 websites and 3 million rows of MySQL data).

I also hived off my public NTP and DNS functions on to a separate box, and after reading some time back about how FreeBSD is a far better operating system for running the NTP daemon that is what the box running these services now is using. And I have to say the improvement in stability is amazing; something around a factor of 10⁴.

There are a few more tweaks to come, but glad to be back.

Going v6

As it happens, my car is a V6. but I'm wanting here to mention the 'upgrading' of Internet Protocol to permit wider access. Back when Vint Cerf and Robert E. Kahn developed the 'new' "Internet Protocol" to enable machines to connect to each other (replacing the old point-to-point method) they came up with the idea of assigning an "Internet Address" to each one. It was a 32-bit number and is nowadays usually written as something like "123.45.67.89". It works pretty well and domain names — such as alisonw.com — get converted into one of these numbers, as does the machine you are reading this on. Thing is, that design (actually ' IPv4' but the one which because widespread) created a limit on the numbers of machines which could be connected to the internet at one time. 4,294,967,296 of them — which is a whole lot of computers, clearly! And in 1980 it was thought (quite reasonably) that the idea there would be more than four and a quarter billion computers on the internet would have been considered completely crazy. But now, almost thirty years on, we are connecting mobile phones, netbooks, IP telephones, webcams, even toasters directly to the internet — and in many cases keeping them online 24 hours a day, not giving others an opportunity to use the same number — so that 4,294,967,296† just won't be enough anymore. Indeed, ARIN ( American Registry for Internet Numbers) reckon they'll run out next year! So a few years back — ten, to be precise — a new numbering system was created. IPv6, as it became known, allows for massively more 'things' to be connected at the same time. In total it would be possible for just over 340,000,000,000,000,000,000,000,000,000,000,000,000 computers, phones, televisions, mobiles, whatever to be online at the same moment. That is 37 zeroes, by the way, or roughly 4,500,000,000,000,000 for every known star in the universe. So plenty of room for expansion without, one hopes, having to go through another redesign for an awfully long time. But one of the issues about IPv6 from a server room or end-user viewpoint is that it is rather like the switch from analogue to digital television, or from VHS tape recording to DVD burning. Some of the kit can be made to work on both, but often software or hardware changes or additions are required to utilise the new IPv6 properly. And once you've moved on you can't then plug back into the old again. Most computers now will work on both, but most mobile phones. And the networking kit — the routers, modems, switches — quite probably won't unless they are very recent (or very expensive). So not only does the intermediate equipment all have to be upgraded (ie. replaced) but also how to get the new and the not-so-new-but-still-connected stuff to talk to each other needs to be sorted out. Disruption of the internet then is pretty much guaranteed. When? about three to five years, probably. I recently upgraded the network kit in my server room and thought I had spec'd IPv6 capable kit throughout. It was only afterwards I discovered misleading marketing in that the ADSL router considered "IPv6 capable" as meaning "IPv6 on the internal can be converted to an IPv4 tunnel outside" which is, of course, pretty useless if you wanted native IPv6 on both sides. One also has to consider the major rewrites of code (and database schemas) in moving from v4 to v6 nomenclature. And how many systems are embedded or non-upgradeable? How mission-critical are they? Is it more cost-effective to keep them - at the risk of degraded network performance overall - rather than replace them to take advantage of the IPv6 opportunities. IPv6 was created ten years ago, and most of the internet backbone already supports it. Your ISP though is probably still working out how to provide it to you — and when. Yes, it will come, indeed it has to come, but "when" is a financial decision as much as a a technical one. † Actually, not all of those are available for use as some are reserved for special uses, and every router in the chain between you and the site you want to use also requires an address.

Yak shaving

"Yak shaving" is a wonderful term — reckoned to have been coined by Carlin Vieri at MIT — that boils down to a "you can't get that done without doing this … and this … and this … " (cf. "when you're up to your neck in alligators, it's easy to forget that the initial objective was to drain the swamp"). Well, earlier today I was thinking about my on-line diary. I wrote the first version — based on individual files for each month that were manually edited — back in 2002, and the following year converted it to use a MySQL database backend that could be edited and maintained fully online. It is still online and has been doing its job very successfully since then. However … It isn't iCal or CalDAV compatible. It does have a dump-to-Outlook option, but that is it. And this afternoon I started wondering again whether I should get around to making it more, um, "Web 2.0'ish". But back to the yak-shaving. After thinking about it, and reading Wikipedia articles, and searching for and reading the sites for different products (OpenSource only, naturally) I ended up concluding that it might actually be sensible to install a complete 'Collaboration Suite' instead of just a calendar server. So I am. If it works I'll let you know!

Servers and alcohol

Today I successfully moved my MySQL databases from a server in Pittsburgh PA to a server closer to home, UK along with one of the sites which uses said databases as a check. All good. To celebrate I had a couple of glasses of nice red wine with dinner … "One glass I'm anyone's,
Two glasses I'm everyone's,
Three glasses I'm no-one's." Except I'm here on my own tonight. Oh dear ;-P