Harry Potter Hating On The Players, Not The Game

Posted on by David Wright

Harry Potter And The Order Of The Phoenix star Daniel Radcliffe enjoyed annoying the paparazzi during his recent stint on the London stage – for six months he deliberately wore the same clothes when leaving the theatre so photographs would be worthless. The 17-year-old was greeted by photographers each night outside the Gielgud Theatre during his stint in controversial West End play Equus, where the teenage actor disrobed onstage every night. Radcliffe quickly realized newspaper and magazine editors wouldn’t publish photos of him wearing the same outfit night after night, because it would look like the pictures were taken on the same day. He says, “They (the paparazzi) were outside the theatre every single night, but we came up with a cunning ruse. I would wear the same outfit every time – a different T-shirt underneath, but I’d wear the same jacket and zip it up so they couldn’t see what I was wearing underneath, and the same hat. So they could take pictures for six months, but it would look like the same day, so they (photos) became unpublishable. Which was hilarious, because there’s nothing better than seeing paparazzi getting really frustrated.”

It’s easy to hate on the paparazzi because it looks very annoying to have to deal with them, but this surely infuriated Radcliffe’s agent. Love ’em or hate ’em the paparazzi are an essential part of the fame machine and working with that machine can make you rich. Disrupt its machinations at your financial peril.

If in 10 years’ time, Danny Radcliffe can’t pay a parparazzo to snap shots of him swimming naked in the Thames he may wish he spent less time biting their hands when they were full of food.

The Time Smear

Posted on by David Wright

Soon after the advent of ticking clocks, scientists observed that the time told by them (and now, much more accurate clocks), and the time told by the Earth’s position were rarely exactly the same. It turns out that being on a revolving imperfect sphere floating in space, being reshaped by earthquakes and volcanic eruptions, and being dragged around by gravitational forces makes your rotation somewhat irregular. Who knew?

That’s the official Google blog.

Now that’s all well and good but eventually we started building systems that need to all talk to each other and agree on the time. If our arbitrary system of time keeping doesn’t/can’t exactly match the (changing) benchmark of the Earth’s position in space, what are we to do? In other words:

Very large-scale distributed systems, like ours, demand that time be well-synchronized and expect that time always moves forwards. Computers traditionally accommodate leap seconds by setting their clock backwards by one second at the very end of the day. But this “repeated” second can be a problem. For example, what happens to write operations that happen during that second? Does email that comes in during that second get stored correctly?

Well, Google does something called a Time Smear:

The solution we came up with came to be known as the “leap smear.” We modified our internal NTP servers to gradually add a couple of milliseconds to every update, varying over a time window before the moment when the leap second actually happens. This meant that when it became time to add an extra second at midnight, our clocks had already taken this into account, by skewing the time over the course of the day. All of our servers were then able to continue as normal with the new year, blissfully unaware that a leap second had just occurred.

Cool! More discussion on the topic from HN here.