Quixotic Evil

Quixotic Evil http://www.quixoticevil.com/ en-gb Nucleus CMS v3.22 © Weblog http://backend.userland.com/rss http://www.quixoticevil.com//nucleus/nucleus2.gif Quixotic Evil http://www.quixoticevil.com/ <![CDATA[Pictures]]> http://www.quixoticevil.com/index.php?itemid=467
There's an episode of 'Upstairs Downstairs' on. In their living room they have a painting on the wall. Well, several, but one of them looks familiar. Really familiar, but I don't know what it is. It's a portrait of a dark-haired woman in a white dress, probably early- to mid-19th century (although I am very far from an expert in such things); she sits smiling gently at the artist with her body facing to his left.

It's going to bug me now.

]]> General http://www.quixoticevil.com/index.php?itemid=467 Sat, 28 Jun 2008 02:45:22 +0000 <![CDATA[Interviews]]> http://www.quixoticevil.com/index.php?itemid=466
]]> Work http://www.quixoticevil.com/index.php?itemid=466 Thu, 19 Jun 2008 20:26:46 +0000 <![CDATA[So, unemployed...]]> http://www.quixoticevil.com/index.php?itemid=465
]]> Work http://www.quixoticevil.com/index.php?itemid=465 Thu, 12 Jun 2008 00:47:15 +0000 <![CDATA[It's as long as a piece of string]]> http://www.quixoticevil.com/index.php?itemid=464
It varies.

In a normal scenario your e-mail software on your local machine makes a connection to an outgoing server (provided by your ISP, or perhaps your company's IT department) which accepts the mail and agrees to send it on. The outgoing mail server then makes a connection to the server listed as being responsible for the domain to which you're sending (the bit after the '@') who accepts it in turn. That machine normally checks the username (the bit before the '@') to decide which mailbox to put it into. Then the recipient can come along using the protocol of their choice and get that mail (or a copy of it) out of the mailbox.

Apart from the last part (or assuming that the person you're on the phone to is impatiently spamming 'Send & Receive') that can all be done in a fraction of a second. People have seen it happen, so they assume it always will.

The first problem is that this is pretty much a minimal setup; best case scenario. It might be a touch shorter if you're using webmail. It's shorter if you have have a mail server on your local machine, but if that's the case you probably don't need to hear what I think about e-mail. In any case there might be more machines in the chain. In our office, for example, local machines submit mail to the internal mail server which then sends it on to the ISP for an extra outgoing stage. On the incoming side, in a large organisation the front-end receiving server might need to pass it back to another mail server to actually get it into a mail box in the right department.

Even without adding more links though, one crucial fact of the mail chain is that not everything can be done at the speed of electricity. Mail - reading envelopes, making connections to pass them on - isn't a very intensive job for a computer, but most mail servers are dealing with... well, I don't want to guess how much mail some of them get. If a server receives mail to relay and doesn't currently have the memory and processor time spare, it'll stick the message in a queue. It might get to the front in seconds - it's a small job in the grand scheme of things - but equally it could be in a very long queue and be there for minutes.
Scanning mail for viruses or trying to spot spam adds to the work a server must do, increasing the likelihood and size of queues. (Notwithstanding the obvious effect of spam increasing the sizes of queues by its nature).

Sometimes servers aren't available. They might have crashed, they might have lost their network connection, they might have had someone unplug them so that he's got a socket to charge his phone, and so on. Well, most mail servers normal people use are in data centres and unlikely to lose power, but network links have to leave the centre and become vulnerable at some point, and anything can crash.
Even stuff that looks unrelated can affect it: if a significant internet pathway is unavailable then it could puts lots of extra traffic down the route you need as a backup route, and that slows everything down. I play WoW (servers in Paris) with some guys in Iceland from my home in the UK: one day last week Iceland lost its connection to the US for a while and all the traffic was going via Europe; one guy whose latency (the time data takes for a round trip) might normally be a couple hundred miliseconds was playing with two second latency. With too much latency, connections are more likely to be given up for dead by a machine that has waited too long for a response from the other party.
Mail servers behave in a variety of ways when they can't contact one another, but one of the more common responses is to put the mail aside for another attempt later, with or without trying to inform the sender. 'Later' might be in a few minutes' time, but it's more likely that a busy server will wait longer before putting the same mail back in its queue, perhaps hours.

Worst of all are those that might need human intervention. Every so often a mail can flag the security rules in server software, normally the in-office servers, and be set aside for an administrator to look at it. Then it will vary even more: some administrators are busy people.

Don't wait days for mail; by far the most common complaint is that it was addressed wrong. In theory the specifications of the mail standards mean that if mail doesn't arrive the sender will be informed, but in practice if you get the username slightly wrong the mail may well end up being delivered to a default recipient for the domain, which is generally someone who gets more mail than he can read and has a habit of deleting it with at best a cursory glance. If you get the domain wrong you might be told when your mail server can't find the domain, but if your incorrect name matches a domain that does have a mail server the mail may end up at another default recipient, this time one in another organisation entirely.

If you do get a failure report for a mail you genuinely sent, for goodness' sake read it. The report will say which server generated it, but note that often one server writes to tell you about a problem it had talking to the next one in the chain. The type of error will normally be described in fairly clear English; the most common reasons include:

Recipient doesn't exist/not recognised: Check the spelling of the part before the '@' (and that you have the correct contact person).
Recipient has reached their mail quota: Contact them some other way and tell them.
Can't find server: Check the spelling of the part after the '@'.
Recipient cannot receive external mail: i.e. address is for internal use only. Contact them and tell them: check that the address you're using is the correct one, and if necessary get them to talk to their IT department.

If a delivery notice tells you that an error is permanent, don't bother resending the mail unless you find something you can change about it. Otherwise it might be worth resending, just refrain from doing so on such a scale that you'd seem impatient or obsessive if all the mails arrive at once (which is entirely possible).

There you go, enough ranting. I've kept it non-technical but that's most of what regular users should realise about e-mail. If any of my peers (or betters) disagree with any of it, say so and I'll do more research and correct anything that's inaccurate.]]> Computers http://www.quixoticevil.com/index.php?itemid=464 Fri, 23 May 2008 13:36:56 +0000 <![CDATA[Shopping List]]> http://www.quixoticevil.com/index.php?itemid=463
There are a number of disadvantages to this. The list has lacklustre support for copying, in that to make a new list with the same contents one must find a new piece of paper and repeat all the expensive append operations that went into the original list. There is no remote access to the list; when I decide that I've got time to go shopping on the way home from work, I find that actually I needed to plan that nine hours ago so that I could take the list with me (which unless I were to use the expensive copy constructor would remove the original list from its stack).

I must find a more efficient solution.]]> General http://www.quixoticevil.com/index.php?itemid=463 Fri, 23 May 2008 10:27:23 +0000 <![CDATA[I Hate MS Exchange]]> http://www.quixoticevil.com/index.php?itemid=462 its work isn't what you want or expect. I'm not a stranger to mail servers - Postfix does what you tell it - but having to support even as few users as I have on Exchange is really doing my head in.

]]> Computers http://www.quixoticevil.com/index.php?itemid=462 Tue, 20 May 2008 09:24:58 +0000 <![CDATA[Bartle Test]]> http://www.quixoticevil.com/index.php?itemid=461 Bartle Test. I don't much like the questions (a lot of them didn't have a clear answer) but apparently I am diagnosed as

EASK: Achiever 60.00%, Explorer 80.00%, Killer 6.67%, Socializer 53.33%

Which sounds about right, to be honest.

]]> Gaming http://www.quixoticevil.com/index.php?itemid=461 Wed, 14 May 2008 14:11:00 +0000 <![CDATA[Full Circle]]> http://www.quixoticevil.com/index.php?itemid=460
About two months ago I went there for the first time. I'd been holding off going for ages, concerned that my character's equipment (or my skill at playing) wasn't up to it, worried that I wouldn't pull my weight. I was one of three healers in the group and I quietly asked the most experienced one if he would mind explaining tactics and so on, since I'd never seen the place before. He said I needn't worry about it being my first time; he could heal a Karazhan run on his own.

For those who don't play, or otherwise don't know it, there's a nice little web application for auditing level 70 characters called Be Imba! (as in 'imbalanced', gaming slang for 'unreasonably good'). It grabs a snapshot of your character and their stuff from the WoW Armory [sic], averages and weights the levels of the items and distils all your hard work in getting that far into a number, a suggestion of what content you should be doing and maybe some recommendations as to how you can improve.

My rating at the time was ~120. Just about enough to be there. The first healer, a holy paladin, was ~190: enough to be somewhere far higher. The other healer was ~170, also more than plenty. According to the combat logs I pulled my weight, and I was well pleased.

I met the paladin again on Sunday; he'd come along to help our guild because we were short of healers for some 25-man content. I was reminded what he said about solo-healing Kara, but every time I've tried to check his Imba score the Armory snap-shot has been of him in PvP gear, giving him a lower rating than in his regular healing gear.

My priest is now ~210. Last night we ran Karazhan on the spur of the moment, short of people because most of the guild already did it this week: I took my druid, now ~120. A priest a little better equipped than mine was to heal it on his own, but in practice I had to switch the druid to healing for one of the boss fights. When he had to leave I swapped characters and found that my priest couldn't quite manage it alone either.

It's not the amount of healing that needs doing: that isn't so difficult really. The problem is mainly with dying. When the enemies' hatred for our healing is split between three healers they will rarely go for one; with one person doing all the healing for a 10-man raid it's easier for them to get annoyed. Besides that, occasionally bad stuff just happens (our first solo-healer tends to be the one it happens to) and if everyone else in the group can't heal (or isn't dressed for it) then a healer death may not be something we can recover from.

I wonder whether that paladin could have solo-healed Karazhan. On paper I'm sure he can - me too, no doubt - but in practice, he'd have to be real lucky...]]> WoW http://www.quixoticevil.com/index.php?itemid=460 Tue, 13 May 2008 13:38:43 +0000 <![CDATA[You can't Rome without Caesar]]> http://www.quixoticevil.com/index.php?itemid=459
]]> General http://www.quixoticevil.com/index.php?itemid=459 Mon, 14 Apr 2008 08:31:26 +0000 <![CDATA[Stuck pixels]]> http://www.quixoticevil.com/index.php?itemid=458 xkcd just alerted me to the fact that stuck pixels in an LCD display can be woken up by putting a little pressure on the screen. My work monitor is complete again!

]]> Computers http://www.quixoticevil.com/index.php?itemid=458 Wed, 12 Mar 2008 13:20:29 +0000