Monthly Archives: October 2009
Another module update
There’s been a spate of bug reports this month (see here, here). Most recently, mod_xml2enc crashing.
A user was having a problem with segfaults. He posted a set of headers, which led me to a bug that’s new with mod_xml2enc. It was a redirection from a proxied backend, with no ErrorDocument or equivalent (as is usual in redirections). mod_xml2enc’s filter got inserted, and failed to check for NULL Content-Type early enough.
It’s a trivial fix, and I’ve released it as Version 1.0.3 (version numbers are cheap)!
Users who downloaded it as part of a mod_proxy_html 3.1.x bundle before today may be affected and should upgrade too. mod_proxy_html itself is not changed, but the bundle is updated.
[UPDATE] I don’t know why WordPress dated this October 29th. It was posted on the 30th!
One of mankind’s more gratuitously stupid activities is faffing about with the clocks twice a year. These days our timepieces seem to know all about time changes, which is in itself a little disconcerting when you’re not expecting it (this is the first time I’ve had a phone which knows about time changes). But that’s by the by.
What really annoys is two of the worst times of year. There’s right now, when already-darkening evenings suddenly advance into mid-afternoon, making for a miserable two months (it cheers up at the end of the year, when daylight, though still short, is perceptibly increasing again). And there’s again in the spring, when we are arbitrarily deprived of an hour’s sleep. Free jetlag.
I don’t mind what we set the clocks to. I just wish we could pick a timezone once and for all, and stick to it.
Bah, Humbug 😦
I have today released mod_proxy_html 3.1.2 and mod_xml2enc 1.0.2.
This is in response to a message from Steffen of ApacheLounge (which distributes Windows binaries of these and other Apache modules), who drew my attention to compilation errors on Windows in both modules. Users of versions 3.1.1 and 1.0.1 on non-Windows platforms have no need to upgrade.
I’ve also made some minor changes to help Apache 2.0 users to build the modules. I don’t know if they’ll still work on Apache 2.0, but at least they now stand a sporting chance. mod_proxy_html 2.5 remains the safe choice for users of Apache 2.0.
Never tried videoconferencing before: I don’t really see the point. But my mum’s just got a new macbook, and upgraded her skype, and wanted to play with her new toy!
So she skyped me. And as soon as I replied, I could see her in a skype window. Looking at it, there was also a button to turn my camera on. Hey presto, we’re videoconferencing!
 Now sharing something on screen (“whiteboard”-style) is another matter, and makes a lot of sense when discussing something complex. And yes, I can see the plain ol’ video has a point too when there’s something visual to demonstrate. But not just for its own sake.
Our posties are going on strike. No snail-mail.
This appears to be, as everyone says, a disaster for the post office. It will clearly speed their decline, by driving adoption of the many alternatives. Letters move online, parcels go to the competition. Losers are the employees, the users, and the owners (that’s us – taxpayers).
But all that is happening anyway. The strike may hasten a decline, but that’s not the same as causing it. The post office is becoming increasingly irrelevant.
In an organisation with history, we can expect to see change, and it’s inevitable that some functions will decline from time to time. Once upon a time, mail coaches were the heart of our transport system for all but the very rich, then came the railways and sent the mail coach into decline. We’ve long since got over lamenting the mail coach, but we still agonise over post office closures, and how to deal with universal collection and delivery.
Regarding actual post offices, we have a very confused debate. My own experience of them is miserable: the last bastion of the forever-long and slow-moving queue to blight our lives. Laments for them seem to focus on oldies regarding them as some kind of social centre, or post offices that double up as village shop. That’s not really about the post office: it’s inertia (and a bit of nostalgia) feeding rent-a-quote journalists.
If we allow that the ink-and-paper letter still has a role to play, then letter collection and delivery is more of a genuine issue: the economics of it would seem to imply higher prices and/or a much-reduced service. That’s something we’re going to have to accept, strike or no strike. So how about a two-level service: a low-cost service with public service obligations doing, say, weekly deliveries, together with faster deliveries at unsubsidised commercial rates in a free market? What’s urgent is online, the rest can wait a few days.
As for other laments, they seem to cast the postie in an untrained-social-worker role. A postie may be a good neighbour and keep an eye on the vulnerable, but that’s an individual matter, scarcely in the job description!
Oh, and for myself I’d love to be able to opt out of paper mail completely. Most of it is junkmail, and most of what isn’t junk should be online. The odd personal letter or card is occasionally a nice touch, but I’d willingly sacrifice the delivery if it could rid me of the junk! Let the post office – or modernised delivery point at a pub/school/church/village hall/etc – hold the letter, and email or text me an alert to go and collect. And introduce penalties on anyone who sends mass mail to opted-out people!
So perhaps the strike isn’t such a bad thing. By accelerating decline, it will accelerate change. Instead of living for years with a lame duck that’s hugely reliant on junkmail and/or in terminal decline, we can move on to something that works in our times.
It’s bin-day tonight. Our (weekly) garbage collection happens Tuesday mornings.
I’ve just thrown away a bunch of good metal lids. The glass jars (and bottles) they come from have gone to the recycling, but lids are not wanted with the glass!
It feels wrong. These are good metal: can’t they be recycled too? Another recycling bin combines tins of all kinds, from the light aluminium of drinks cans, to the much heavier food tins things like tinned tomatoes come in. That’s an eclectic mix of different metals: can’t lids from a pickle jar go in with them? It’s unclear: most of those lids have a non-metal surface – usually a thin film of something plastic-ish facing the food. Would that mess something up?
Similarly some things have plastic lids: can those go in the recycling bin for plastic bottles?
Can the recycling industry provide clear guidelines on such things? For example, where the bottle bank tells you to remove lids, perhaps it could suggest where metal and plastic lids can be recycled.
Just back from our mini-break. Yesterday was the best day: we found the best sights, and the best food!
Just wanted to share the snapshot I’ve made the background on my ‘phone. Sunset on the southwest coast path, on the gorgeous stretch just west of Ilfracombe. Yes, there’s a little of this kind of scenery in the UK (the Exmoor coast is the heart of it), but it’s the kind of thing we Brits normally expect to have to travel abroad for.
Escaping from Tavistock’s worst week, we’re taking a couple of days away. Not far away: a guest house in Ilfracombe, on the north coast of Devon. An attractive area in many ways, on the coast path (long-distance walk) and just near Exmoor (national park), among other things.
Today we took the ferry to Lundy Island, which is known mostly for its wildlife, particularly seabirds, which nest in huge numbers on the cliffs that almost completely encircle the island. We’re out of season for the most exciting bird life, but that was somewhat compensated by a distant sight of seals in the water, down the cliff on the eastern (more sheltered) side of the island.
A drawback with that is that we took the main tourist boat, which meant as we started out we were amongst a great crowd. We diverted ASAP from the main tourist route, after which things were more relaxed. Worse, the boat’s timetable said return at 18:00, which should’ve given us us the day on the island, but they then told us the return was at 15:30 to arrive back at 18:00, leaving us a little under three and a half hours on the island. That puts us under time pressure, and makes the extortionate cost of the overcrowded and less-than-comfortable crossing seem poor value. Lesson: if and when we go again, don’t make it a day-trip!
Back at the guest house, and enjoying the tranquillity. It’s far quieter evening than anything I encounter at home, and reminds me of an important aspect of what I’m looking for in a new place.
mod_proxy_html bugfix 3.1.1
It’s always gratifying to get constructive feedback from users. That includes bug reports backed by sufficient information to make a diagnosis.
The bug I’ve just fixed today must’ve been there unreported for years: the code in question is unchanged since 2004. It won’t affect most users, but it hits when ProxyHTMLMeta is On and parsing the <meta> tag fails, which can happen due to capitalisation. And it’s serious: it dereferences a null pointer and segfaults!
This is sufficiently serious to merit an immediate new bugfix release, 3.1.1, which should be published within a few hours. Thanks to user Jie Gao for reporting the bug and supplying a perfect test case!
While I’m on the subject, another user pointed out that 3.x won’t compile on Apache 2.0 for a trivial reason. While 2.0 support isn’t really a priority any more (Apache 2.0 users can of course run mod_proxy_html 2.5), I don’t want to break it gratuitously. So I fixed that too. (I made a corresponding fix in mod_xml2enc in svn, but that doesn’t call for a new release).
 or if there were reports that trace back to this, they were too vague to be useful.
Reverse Proxying Tutorial
My reverse proxying tutorial seems to be a standard reference on the subject. Unfortunately it’s been allowed to get out-of-date as the software concerned has developed.
I updated it a week or two ago to fix those parts that are no longer correct or recommended, and to describe practice with Apache 2.2, mod_proxy_html 3.1, and mod_xml2enc. Having today seen someone on IRC ask about a configuration clearly derived from the outdated version, I thought I should blog it here in the hope of reaching a few more googlers.
I may expand it a bit further to cover additional subtopics, particularly internationalisation. I’m half-tempted to add something brief on other common reverse-proxying topics: authentication and single-sign-on, caching, load-balancing, and perhaps even mod_security. But at the same time, I’m not particularly keen to grow it long enough to do justice to such topics. Anyone with views on whether this would or wouldn’t be useful, feel free to comment here.