2 ms·
> When too many nodes fail or are unreachable Don’t forget the nasty bit about partitions: if I think nodes 1-5 are reachable and the rest are unreachable, I c
by amluto 3y ago
> When too many nodes fail or are unreachable
Don’t forget the nasty bit about partitions: if I think nodes 1-5 are reachable and the rest are unreachable, I can’t assume that the rest of the nodes are down or idle — some other client may think that nodes 1-5 are unreachable but nodes 6-15 are reachable.
- slashdev 3y agoThat's correct
- rstuart4133 3y agoThe nasty bit you speak of is split brain, and it's addressed by C. C says that if you read you always get the last thing written. If the nodes can't communicate and someone does a write then the other half can't return what was written, so CAP is broken.
- thayne 3y agoWell a partition means that some nodes are unreachable, at least from the perspective of some other nodes. The tricky part is that reachability is not necessarily consistent across the entire network.