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> CP systems can be made to be highly available in practice. Yes don't, if you happen to have Google's level infrastructure. Complete with private fiber connec

by rdtsc 9y ago

> CP systems can be made to be highly available in practice. Yes don't, if you happen to have Google's level infrastructure. Complete with private fiber connection down to GPS synchronized clocks in your data centers. Otherwise sometimes you don't have a choice. Now I am not being sarcastic as I understand Google offers Spanner as an API in GCP so you could technically do that by paying for it. https://cloud.google.com/spanner/ https://cloud.google.com/spanner/ Also in general it is important to keep in mind that keeping consistency in a large distributed system is fighting against the laws of physics. There is nothing wrong with fighting them, and it sure is fun to do but it takes effort and money. Often is possible you can architect your solution to work with eventually consistency. There are CRDTs and other things that can help there. Eventually consistent system have also been around for a while so it is not a totally new and uncharted territory. The bottom line is consider the underlying assumptions. What is true for Google maybe not be and probably isn't true for your use case.

canes123456 9y ago
It not clear at to me what you are actually advocating for. The article is pretty clear that most people should choose a CP database over an AP database. This is true regardless of your scale unless you don't care about consistency at all. A start up does not need to make a CP system highly available but they will likely need consistency. They can probably make eventually consistency work for them but it does take effort and money. I don't see many cases were AP is the right choice. Again CRDT are good but you need to design carefully to make sure you system can work with eventually consistency. Once you have done that you are only gaining availability during partitions which does not increase your up time much. I would recommend a standalone database, a stock CP database, or renting spanner over an AP if time and money is a concern.

by rdtsc 9y ago

canes123456 9y ago

It not clear at to me what you are actually advocating for. The article is pretty clear that most people should choose a CP database over an AP database. This is true regardless of your scale unless you don't care about consistency at all. A start up does not need to make a CP system highly available but they will likely need consistency. They can probably make eventually consistency work for them but it does take effort and money. I don't see many cases were AP is the right choice. Again CRDT are good but you need to design carefully to make sure you system can work with eventually consistency. Once you have done that you are only gaining availability during partitions which does not increase your up time much. I would recommend a standalone database, a stock CP database, or renting spanner over an AP if time and money is a concern.