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The above comment is, well, not very informed. CAP is a simple, generic academic model. Researchers and implementers moved on from that a long time ago. In th

The above comment is, well, not very informed. CAP is a simple, generic academic model. Researchers and implementers moved on from that a long time ago. In the case of Google, they have partition-free networks for newer databases, so CAP rarely applies. Galera/Percona Cluster has solutions for all the above also. Generally multi-master writes continue, and the behind server either catches up or gets automatically rebuilt. MySQL 8 has something equivalent to Galera. I would recommend testing (or waiting) a year for multi-master Aurora to bake. In the meantime, you can use Percona Cluster if you can't wait. You can learn more here about the state-of-the-art in multi-region, multi-master RDBMS' here: http://www.jebriggs.com/blog/2017/11/internet-latency-and-multi-master-database-transactions/ http://www.jebriggs.com/blog/2017/11/internet-latency-and-mu... Source: DBA who's operated Percona Cluster for 5+ years. Contact me if you need extreme database performance or availability.

kjeetgill 7y ago
I don't strictly disagree with you, but the parent has a point. It's not a technical outline of the difficult tradeoffs distributed systems must make[0], rather an ad copy where they can promise you the world and it's hard to tell what's exactly true. Even igoring Amazon, MySQL/Percona's mha story has had a history of buggy, weak, imprecise promises. [0] I guess Google level special sauce gets a pass since they have the most published about specially clocked hardware, and how it changes DB design.
zzzcpan 7y ago
> In the case of Google, they have partition-free networks for newer databases, so CAP rarely applies. No, asynchronous networks cannot physically be partition-free. They are actually always partitioned. > Galera/Percona Cluster has solutions for all the above also They don't have solutions to all of the above.
ianamartin 7y ago
This is an incredible comment. You have some real chutzpah, sir. I respect that. You are as wrong as can possibly be, but this is a bold move.
SahAssar 7y ago
What exactly is a "partition-free network"? In my understanding no such thing exists, a partition can happen even if all the servers run on the same physical hardware (because of networking stacks, bugs, misconfiguration and so on), and even if they think that no such thing can happen if runs for eternity it will eventually happen. The question that CAP asks is what happens when a partition happens? Does the DB C: Stay consistent but not available A: Stay available but not consistent There is no other option.

kjeetgill 7y ago

I don't strictly disagree with you, but the parent has a point. It's not a technical outline of the difficult tradeoffs distributed systems must make[0], rather an ad copy where they can promise you the world and it's hard to tell what's exactly true. Even igoring Amazon, MySQL/Percona's mha story has had a history of buggy, weak, imprecise promises. [0] I guess Google level special sauce gets a pass since they have the most published about specially clocked hardware, and how it changes DB design.

zzzcpan 7y ago

> In the case of Google, they have partition-free networks for newer databases, so CAP rarely applies. No, asynchronous networks cannot physically be partition-free. They are actually always partitioned. > Galera/Percona Cluster has solutions for all the above also They don't have solutions to all of the above.

ianamartin 7y ago

This is an incredible comment. You have some real chutzpah, sir. I respect that. You are as wrong as can possibly be, but this is a bold move.

SahAssar 7y ago

What exactly is a "partition-free network"? In my understanding no such thing exists, a partition can happen even if all the servers run on the same physical hardware (because of networking stacks, bugs, misconfiguration and so on), and even if they think that no such thing can happen if runs for eternity it will eventually happen. The question that CAP asks is what happens when a partition happens? Does the DB C: Stay consistent but not available A: Stay available but not consistent There is no other option.