Thanks a lot Peter. So basically we would need to choose a consistency other than QUORUM. I think in our case consistency is not necessarily an issue since our data is write-once, read-many (immutable data). I suppose having a replication factor of 4 would result in two nodes in each datacenter having a copy of the data. If there's a flaw in my logic, please let me know : ]
On Sun, Dec 12, 2010 at 2:04 PM, Peter Schuller <peter.schul...@infidyne.com> wrote: >>> Is my logic wrong here? Is there a way to ensure the nodes in the >>> alive datacenter respond successfully if the second datacenter is >>> lost? Anyone have experience with this kind of problem? >> >> It's impossible to achieve the consistency and availability at the >> same time. See: > > (Assuming partition tolerance) > > Anyways, to expand a bit: The final consequence is that if you have a > cluster that really does need QUORUM consistency, you won't be able to > survive (in terms of availability, i.e., the cluster serving your > traffic) data centers going down. If you want to continue operating in > the case of a partition, you (1) cannot use QUORUM and (2) your > application must be designed to work with and survive seeing > inconsistent data. > > -- > / Peter Schuller >
