Colin's Journal: A place for thoughts about politics, software, and daily life.
April 29th, 2003
There and back again
We got back last night from a short trip back home to the UK. The last flight back is a nice one, we had enough time for a meal in London before heading to Heathrow, and by getting in after midnight you feel absolutely no guilt going to bed straight away.
The UK had mixed, but generally mild, weather. It was nice to see greenery again after such a long winter, although on return we found the start of spring underway here in Toronto. As a concession to the SARS madness we now have anti-bacterial soap in the bathrooms at work and disinfectant wipes for our keyboards and phones…
April 21st, 2003
Time for a nice cup of tea and a sit down…
This site is inspiring, and proves that maybe owlfish.com wasn’t such a bad name to choose after all: http://www.nicecupofteaandasitdown.com/.
On a more serious note there’s been some positive moves in Cyprus recently, including the opening of the borders, along with positive moves from Turkey, so there is some hope for finally resolving this long running dispute…
April 21st, 2003
Taxes
So why is it that a student that has paid no tax, and owes no tax to either the federal or provincial government ends up with more extensive and complex paper work to fill out, than say a migrant worker who has paid lots of tax, and still owes a little more?
It’s a challenge to try and follow the bizarre arithmetic involved in filing taxes, which in some cases seems to be deliberately obscure. The ones that stump me:
- What the hell is the GST/HST credit?
- How much is the Ontario surtax? (It’s computed as: (Line 35 minus $3,685) x 20% + (Line 35 minus $4,648) x 36%)
- Why do you multiply line 43 by two to get line 44?
April 19th, 2003
New release of TALAggregator
I’ve just uploaded version 0.3 of TALAggregator. This release addresses some template bugs (images now sit properly underneath one another), and cleans up some missing things (like user agent identification).
April 16th, 2003
It’s been a while since my last posting, almost a week in fact. During this time we’ve experienced summer and the reversion to winter. Some beer has been drunk, conversation partaken and food eaten. As you can tell not much of note has occurred, and so I’ve spared you the pain of reading about it as it happens.
Regarding things that did happen:
- I read Howl’s Moving Castle upon recommendation. It’s OK, but as children’s books go there are far better (Maurice and the inevitable Potter series).
- Although there don’t appear to be many levels it looks like Pingus is now worth playing.
April 10th, 2003
A day in the life…
A day of work well done, a sore ear. An afternoon of talking for hours on end, hashing out opinions and theories.
Hello? Ah John you are there, do you know if Tim is joining us? ... Sorry I can't hear you! Are you on speaker? ... How do we avoid the question of xxx coming up? ... [xyz has left the call] ... What are the customer's expectations? ... I don't agree, they don't want that kind of detail... ... [xyz has joined the call] ... I sent an email out yesterday which described what that will take... ... OK we'll take that offline. ... Dave are you still there? ... Sorry I've got another call coming up, send me an email...
April 10th, 2003
LiveJournal now has images in there RSS!
LiveJournal now produces RSS that contains images! This is great news, and something I had been hoping would be added.
The size of the images did bring out a visual bug in my aggregator’s display template/css which I’ve now fixed. I’m going to hold off issuing a new version though until some more time has passed so that I can include other bug fixes.
Live journal changing RSS format from 0.91 to 2.0 also meant all articles currently in the feed were flagged as new, which is unfortunate. There’s no easy way around the problem though, handling it would require schema changes and more complex logic than seems worth while.
April 9th, 2003
Visiting the US
According to these figures there are approximately 15-20% fewer people being inspected crossing into the US since before the 11th of September 2001. The figures don’t go back much further (they currently show seasonally adjusted figures, earlier figures show absolute numbers and so aren’t comparable). I wonder how much of this drop can be attributed to economic woes versus a drop in the desire to either leave (residents returning count in the inspection stats) or enter the US?
Contrast (if not comparison) with the UK is difficult because the immigration situation is more complex. EU nationals entering and leaving the UK are not “inspected” and leave no paper trail (you generally just wave your passport at someone). Travel within the UK’s common area (Isle of Man, etc) also confuse things. Despite this there is an easy to read press release here that covers the number of overseas residents entering the UK. The situation seems to be broadly one of no change:
The number of overseas residents arriving in the UK during the period December 2002 to February 2003, seasonally adjusted, was 16 per cent higher than in the same period a year earlier. However, it should be noted that the end of 2001 and early 2002 were affected by the September 11th terrorist attacks in the USA. Comparing December 2002 to February 2003 with the same period two years earlier (December 2000 to February 2001), there was an increase of one per cent in the number of overseas residents arriving in the UK.
April 9th, 2003
More musing on publish-subscribe
This is a follow on from my thoughts yesterday regarding whether a publish-subscribe model for RSS would be useful.
The more I think about it the less use I see for distributing RSS via a publish-subscribe service, like the one I did an initial specification for yesterday. While it could be considerably more efficient to distribute weblog changes via such a service, I don’t see a compelling reason to make the investment required in software to support such services. The result for the end user is the same as it is today, it just takes less bandwidth.
While the rss feed for this weblog is by far the most requested file on owlfish.com, it’s very low down on the bandwidth usage (less than 2%). From a client perspective the extra overhead of requesting and parsing RSS files versus talking to a subscription server is minimal, and with web based RSS aggregators the overhead disappears entirely (the host of the aggregator takes the load instead).
There is one use case that I can think of however which may benefit from such a publish-subscribe method. Imagine if most web pages had a ‘Watch This Page’ button on them somewhere (similar to the orange XML button). Selecting this button would subscribe the user, through there chosen subscription service, to notifications of changes to that page. Instead of having to remember to check back on pages occasionally for changes you could just click on this button, and you will now be notified if it changes. Would this be useful?
The infrastructure required to deploy such a system isn’t that difficult to roll out. The button would be a link to a file (potentially generated dynamically) which would contain the resourceID for this page, and the URL for the publishing notification server. On selection the browser would download this file, send it to a program installed locally, which in turn sends the details to the user’s chosen subscription notification server.
April 8th, 2003
Thoughts on a publish-subscribe service for RSS
A posting by Dan on the way we use RSS to notify users about updates to weblogs inspired me to consider an alternative. It’s not immediately clear that the polling of a web-server once an hour using conditional GET of an RSS feed is really a problem. As I say in the starting paragraph of my new article on the subject:
I’ve seen it estimated that a conditional HTTP GET on an RSS file takes about 200 bytes of bandwidth. That’s not very much at all, even with a thousand clients polling once per hour the total bandwidth cost in a month will be about 137MB. It’s still worth looking at alternatives though to see whether there is a more efficient way of being notified when a weblog is updated.
Is it worth the development effort required to reduce this kind of load? If we did, would it really work? I’m not convinced yet, but I have taken a stab at describing a web service that could by implemented as an alternative. I did consider existing alternatives like headline distribution in Jabber, but they still rely on polling at the end of the day.
Here’s my proposal, if you are interested in this sort of thing I would appreciate the feedback.
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Email: colin at owlfish.com