Disclaimer, i am using this text from wikipedia in order to get things clear in my head 🙂
Please, read and understand the cap theorem:
from the bless wikipedia:
In theoretical computer science, the CAP theorem, also known as Brewer’s theorem, states that it is impossible for a distributed computer system to simultaneously provide all three of the following guarantees:
- Consistency (all nodes see the same data at the same time)
- Availability (a guarantee that every request receives a response about whether it succeeded or failed)
- Partition tolerance (the system continues to operate despite arbitrary partitioning due to network failures)
In 2012 Brewer clarified some of his positions, including why the oft-used “two out of three” concept can be misleading or misapplied, and the different definition of consistency used in CAP relative to the one used in ACID.