With 3 nodes, and RF=3, you can always use CL=ALL if all nodes are up, QUORUM if 1 node is down, and ONE if any two nodes are down.
The exact same thing is true if you have more nodes. -Tupshin On Apr 14, 2014 7:51 AM, "Markus Jais" <markus.j...@yahoo.de> wrote: > Hi all, > > thanks. Very helpful. > > @Tupshin: With a 3 node cluster and RF 3 isn't it a problem if one node > fails (due to hardware problems, for example). According to the C* docs, > writes fail if the number of nodes is smaller than the RF. > I agree that it will run fine as long as all nodes are up and they can > handle the load but eventually hardware will fail. > > Markus > > > > > > Tupshin Harper <tups...@tupshin.com> schrieb am 13:44 Montag, 14.April > 2014: > > I do not agree with this advice. It can be perfectly reasonable to have > #nodes < 2*RF. > It is common to deploy a 3 node cluster with RF=3 and it works fine as > long as each node can handle 100% of your data, and keep up with the > workload. > -Tupshin > On Apr 14, 2014 5:25 AM, "Markus Jais" <markus.j...@yahoo.de> wrote: > > Hello, > > currently reading the "Practical Cassandra". In the section about > replication factors the book says: > > "It is generally not recommended to set a replication factor of 3 if you > have fewer than six nodes in a data center". > > Why is that? What problems would arise if I had a replication factor of 3 > and only 5 nodes? > > Does that mean that for a replication of 4 I would need at least 8 nodes > and for a factor of 5 at least 10 nodes? > > Not saying that I would factor 5 andn 10 nodes, just curious about how > this works. > > All the best, > > Markus > > > >
