NewSQL databases fail to guarantee consistency and I blame Spanner

Post by skrebbel » Fri, Sep 21, 2018, 5:07 PM UTC

hosay123 wrote: post #60

wpietri wrote: post #52

Earlier quoted context omitted.

So yes, Google can be very impressed with Google. But I'm not sure that's the issue here. Is it really surprising that people who have extremely precise time needs and a whole team devoted to solving them would notice issues that other people wouldn't? I think it's a very common pattern that a product has some set of trailblazer users who find issues before the people who make the product. Also, I think you're over-i…

If some condition existed that exceeded GPS intended design, you most certainly wouldn't learn of it first from some random anecdote on HN.. more likely the front page of the BBC as the transportation system instantly collapses So the anecdote itself is noise, it's intended to show how seriously intractable a problem accurate time is, but it doesn't do that, instead it only demonstrates OP's lack of familiarity with…

Post by gregdunn » Fri, Sep 21, 2018, 5:10 PM UTC

mannykannot wrote: post #108

Rapzid wrote: post #87

Earlier quoted context omitted.

People are going to notice a 300m deviation due to landmarks and their eyes.

Rarely, if you are navigating at sea or in the air or in the woods... and even on the road, it is not uncommon for my GPS device to be clearly off without justifying the conclusion that there is a fault in a satellite.

Post by emiliobumachar » Fri, Sep 21, 2018, 5:14 PM UTC

mannykannot wrote: post #108

Rapzid wrote: post #87

Earlier quoted context omitted.

People are going to notice a 300m deviation due to landmarks and their eyes.

Rarely, if you are navigating at sea or in the air or in the woods... and even on the road, it is not uncommon for my GPS device to be clearly off without justifying the conclusion that there is a fault in a satellite.

Post by dleslie » Fri, Sep 21, 2018, 5:17 PM UTC

skrebbel wrote: post #131

hosay123 wrote: post #60

Earlier quoted context omitted.

If some condition existed that exceeded GPS intended design, you most certainly wouldn't learn of it first from some random anecdote on HN.. more likely the front page of the BBC as the transportation system instantly collapses So the anecdote itself is noise, it's intended to show how seriously intractable a problem accurate time is, but it doesn't do that, instead it only demonstrates OP's lack of familiarity with…

Sub-millisecond flaws in GPS would make the transportation system collapse? Why?

Post by taeric » Fri, Sep 21, 2018, 5:18 PM UTC

apoverton wrote: post #107

hinkley wrote: post #100

Earlier quoted context omitted.

I’m sure someone has talked about this and proven or disproven it, but I’ve always been a little uneasy with the truetime protocol. I mean it’s faster than Raft, but for the use case maybe we are trying to fix the wrong problem? If two events are independent, it matters very little what order we record them in the system of record. My whole career we have been building cause and effect at transaction time but when we…

I think if 2 events are independent then you can use an eventually consistent DB like Cassandra and move on with your day. The importance of something like TrueTime arises when you have an example like in the article. Step 1: remove your parents from seeing your photo albums. Step 2: post your spring break photo album