Short question: Do cassandra only *really* shine when running a cluster with lots of nodes?
Same question in a lengthy version: If what I want to obtain from my cassandra cluster is given as this: a) protection against data loss if nodes disk-crash b) good uptime, if servers become unavailable or are taken down for service c) good read performance (notice: I do not need exceptionally good write performance) So, if I setup a cluster with 3 nodes only, and set ReplicationFactor=3, and use QUORUM reads and writes, do I then have a chance of obtaining my goal? Or do I need a cassandra cluster with "lots" of nodes? I have no number for what I mean with "lots", but I regard 2-3 nodes as NOT being a lot :-) (I know there are many variables here, but bear with me). Here are my thoughts: With respect to (a): RF=3 will mean all (3) nodes with have all data on them, which I think of as "good enough protection". So, goal reached on that one. But what about (b): With QUOROM reads and writes and RF=3, I can take down one and only one node at any time, and still be up and running, right? If correct, I guess this is up to me, if that is okay :) Last, on (c): Given that what we are aiming at is good read performance, does it then make much sense, to run a cassandra cluster if we only plan on having 3 nodes? I mean, then there won't be that many nodes to distribute reads to? /Per
