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Jorgen Thelin: scale this

Architectural Cross-Pollination

Jorgen Thelin on the UK national lottery network:

This was the world's largest networked lottery system when it was launched in November-1994 with 10,000 terminals. It now has about 25,000 terminals, and always has some extremely high system availability and peak volume processing requirements. Just before the ticket sales cutoff point at 19:30 on Saturdays and Wednesdays, you can pretty much guarentee that the network access will achieve close to 100% concurrency, especially for Roll-over or other special draws. Contrast this with other big networked systems of this size where on a bad day you may get up to 5% concurrency. Also, there are very severe reputational and good-will risks, not to mention customer anger, if the system is ever down - and particularly if it crashes just before the ticket sale cut-off time. To my knowledge, this has only ever happened once or maybe twice in the last 8 years.

Wow. I can't begin to imagine what this kind of capacity would cost to roll out using today's web technologies (most people might surprised at how few concurrent requests it takes to slashdot a site). I know there are huge improvements to be had in web capacity using event based rather than thread per request architectures - but maybe I've been thinking too low on what a performant system can be.


January 9, 2003 12:12 AM

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Bill de hra posted some comments about my earlier posting "Architectural Cross-Pollination" about scalable systems: Wow. I can't begin to imagine what this kind of capacity would cost to roll out using today's web technologies (most people might [be] ... [Read More]

Tracked on February 4, 2003 12:30 AM