3 ms·
Really liking CockroachDB so far. Also reading through their site, I didn't know Google's Spanner required AtomicClocks! Holy deep pockets Batman!
by filereaper 10y ago
Really liking CockroachDB so far.
Also reading through their site, I didn't know Google's Spanner required AtomicClocks! Holy deep pockets Batman!
- jzelinskie 10y agoI used to think this as well, until I started talking to more shops that own their own hardware. As it turns out, having atomic clocks isn't quite as extraordinary as you think. If there's enough competition in the public cloud, we might be seeing them there pretty soon.
- technion 10y agoNot quite atomic - but an interesting Raspberry Pi project is an NTP server with a GPS unit. It doesn't take deep pockets a all and it offers far more accurate time sync than any average person needs. NTP will rate it at a lower stratum than any network-only time server. I had one in the NTP pool for a while.
- MichaelGG 10y agoI don't think such clocks are that expensive. A quick search shows several companies offering them ready to go. I'd guess that even relative to the engineering time involved, the cost of the clocks was irrelevant. GPS NTP servers start at $1000, but I dunno how much that delivers. The actual GPS signal is probably accurate enough, but the rest of the hardware chain on a $1000 box might not be <1ms. Google might have also wanted a backup in case antennas are disturbed or GPS signal somehow interrupted? But even then - just because Google chose 7ms doesn't mean everyone else has to. Drop a GPS NTP master at each site and live with that? I wouldn't imagine it'd get much worse than 10-20ms? I don't really know a whole lot about this though.
- jasonwatkinspdx 10y agoOnly a small number, used as insurance/backup for problems with GPS. It's not really a huge problem for someone buying many racks of their own equipment.