So we're going to have to take a slight hit to our resilience and reduce the number of A records we return for a DNS lookup to one instead of two.
How does that improve matters? Even if more or less every Vista user used the IP that was closest to 192.x, wouldn't other users still see the benefit of multiple records? In fact, they could make non-vista systems prefer the other addresses if they used effectively duplicates of the other addresses. Costs a few extra IPs, but surely that's not a problem for a site with millions of page views?
In case that wasn't clear, say they have 3 A entries:
Vista will always use A. Other systems will use all with 1/3 probability. If servers B & C were aliased to very similar IPs to the ones they already have, they'll end up with this situation:
Vista will still prefer A, but other systems will choose B or C twice as often as A, compensating for some of the extra load. You could play this game further if you wanted to.
An orthogonal solution is to get hold of some more servers that have an IP with the same "distance" as A. Vista should distribute traffic evenly across these; combined with the duplication suggested above to draw other OSes to the non-vista servers, it should be possible to make this less of a problem.
Still, if big companies are affected by this, I'm sure they can pressure Microsoft into abandoning this method. Actually, the author mentions that Windows 7 seems to have a more sane policy, so you'd just need such hacks until Vista fades back into insignificance.
So we're going to have to take a slight hit to our resilience and reduce the number of A records we return for a DNS lookup to one instead of two.
How does that improve matters? Even if more or less every Vista user used the IP that was closest to 192.x, wouldn't other users still see the benefit of multiple records? In fact, they could make non-vista systems prefer the other addresses if they used effectively duplicates of the other addresses. Costs a few extra IPs, but surely that's not a problem for a site with millions of page views?
In case that wasn't clear, say they have 3 A entries:
Vista will always use A. Other systems will use all with 1/3 probability. If servers B & C were aliased to very similar IPs to the ones they already have, they'll end up with this situation: Vista will still prefer A, but other systems will choose B or C twice as often as A, compensating for some of the extra load. You could play this game further if you wanted to.An orthogonal solution is to get hold of some more servers that have an IP with the same "distance" as A. Vista should distribute traffic evenly across these; combined with the duplication suggested above to draw other OSes to the non-vista servers, it should be possible to make this less of a problem.
Still, if big companies are affected by this, I'm sure they can pressure Microsoft into abandoning this method. Actually, the author mentions that Windows 7 seems to have a more sane policy, so you'd just need such hacks until Vista fades back into insignificance.