Thanks Robert. Also, I have seen the node-repair operation to fail for some nodes. What are the chances of the data getting corrupt if node-repair fails? I am okay with data availability issues for some time as long as I don't loose or corrupt data. Also, is there way to restore the graph without having to backup the token ring range but just the data backup?
-Pranay On Mon, Dec 29, 2014 at 1:58 PM, Robert Coli <rc...@eventbrite.com> wrote: > On Mon, Dec 29, 2014 at 1:40 PM, Pranay Agarwal <agarwalpran...@gmail.com> > wrote: > >> I want to understand what is the best way to increase/change the replica >> factor of the cassandra cluster? My priority is consistency and probably I >> am tolerant about some down time of the cluster. Is it totally weird to try >> changing replica later or are there people doing it for production env in >> past? >> > > The way you are doing it is fine, but risks false-negative reads. > > Basically, if you ask the wrong node "does this key exist" before it is > repaired, you will get the answer "no" when in fact it does exist under the > RF=1 paradigm. Unfortunately the only way to avoid this case is to do all > reads with ConsistencyLevel.ALL until the whole cluster is repaired. > > =Rob >
