On 2017-07-20 13:23 (-0700), Roger Warner <rwar...@pandora.com> wrote: > Hi > > Iâm a little dim on what multi datacenter implies in the 1 replica case. > I know about replica recovery, how about ânode recoveryâ > > As I understand if there a node failure or disk crash with a single node > cluster with replication factor 1 I lose data. Easy. > > nodetool tells me each node in my 3 node X 2 datacenters is responsible for > ~1/3 of the data. If in this cluster with RF=1 a node fails in dc1 what > happens ? in 1 dc with data loss can the node be ârestoredâ from a node > in dc2?. Automatically? >
With RF=1 and SimpleStrategy, if you lose any instance, you've lost the only copy of the data. With NetworkTopologyStrategy, if you have RF=1 in each DC, if you lose any given instance in one DC, it can be rebuilt with the data from the other DC. RF=1 is a pretty dangerous option, especially since rebuilds over a WAN tend not to be super reliable for many people (it works, but that doesn't mean it's easy). --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
