3 ms·

If you assume you can "sync faster than requests come in to the system", you've necessarily chosen C not-P, i.e. you don't have a distributed system (and in pra

If you assume you can "sync faster than requests come in to the system", you've necessarily chosen C not-P, i.e. you don't have a distributed system (and in practice you've probably chosen not-A too).

j16sdiz 3y ago
CAP is a false choice. In practice, people choose (mostly C)+(mostly A)+(mostly P).
- woooooo 3y ago
  "Mostly consistent" is not good enough for many applications. The thing most people pick in practice is CA, single master with hopefully a replicated backup.
  - seneca 3y ago
    Absolutely. And that's the right choice IF you can make it. Switching to CP or AP is something you should do because you're forced to. That's something lost on a lot of modern engineers, I think. Distributed Systems are something you do because you have to, not because they're the best approach inherently.
  - deleted 3y ago
    [deleted]
- dartos 3y ago
  That’s because for many use cases, you don’t need to be perfect. The theorem is about being perfectly C, A, and P
- hndc 3y ago
  You've misunderstood the theorem. It doesn't say you can't achieve any combination of mostly C/A/P; it says you can't have perfect C, A, and P at the same time.
- hasty_pudding 3y ago
  Those things are binary. You have them or mot. Theres no: 'mostly'. If you have more than two hosts, you have P. If you have delay to sync, you have C. If you send inaccurate data instead of waiting you have A. Theres no 'mostly'
hasty_pudding 3y ago
if you choose consistency than the only negative result of a distributed system is consistency based latency. i.e. Time to become consistent which reduces your response time to the client. so there's a linear relationship between reducing sync time and reducing response time until at some point in reducing sync time you reduce response time below a level you give a shit about... and you have all 3 of consistency, availability, and partitioning and then you have beaten the CAP theory

j16sdiz 3y ago

CAP is a false choice. In practice, people choose (mostly C)+(mostly A)+(mostly P).

woooooo 3y ago
"Mostly consistent" is not good enough for many applications. The thing most people pick in practice is CA, single master with hopefully a replicated backup.
- seneca 3y ago
  Absolutely. And that's the right choice IF you can make it. Switching to CP or AP is something you should do because you're forced to. That's something lost on a lot of modern engineers, I think. Distributed Systems are something you do because you have to, not because they're the best approach inherently.
- deleted 3y ago
  [deleted]
dartos 3y ago
That’s because for many use cases, you don’t need to be perfect. The theorem is about being perfectly C, A, and P
hndc 3y ago
You've misunderstood the theorem. It doesn't say you can't achieve any combination of mostly C/A/P; it says you can't have perfect C, A, and P at the same time.
hasty_pudding 3y ago
Those things are binary. You have them or mot. Theres no: 'mostly'. If you have more than two hosts, you have P. If you have delay to sync, you have C. If you send inaccurate data instead of waiting you have A. Theres no 'mostly'

hasty_pudding 3y ago

if you choose consistency than the only negative result of a distributed system is consistency based latency. i.e. Time to become consistent which reduces your response time to the client. so there's a linear relationship between reducing sync time and reducing response time until at some point in reducing sync time you reduce response time below a level you give a shit about... and you have all 3 of consistency, availability, and partitioning and then you have beaten the CAP theory