On Thu, Jan 20, 2011 at 10:47 AM, Oleg Proudnikov <ol...@cloudorange.com> wrote: > Q1. Is it possible that Cassandra will drop both replicas for a given column > during these losses? Or does it guarantee that one replica is still written?
It guarantees that if the requested ConsistencyLevel is not achieved, client will get a TimedOutException, which is a signal you need to add capacity to handle what you are throwing at the cluster. > Q2. What does the lack of client exception mean? Does it tell me that at least > one replica is written? As above. > Q3. If I were to use CL=ALL, would I get an exception(s) on the client(s) for > those losses? Yes. > Q2. Considering that I did not get an exception I will assume that one replica > is retained. Now, if the nodes stay up and the load on the cluster goes down, > will Cassandra attempt to create 2nd replica? Or will the 2nd replica be > created > on a read? Is there a way to recreate lost replicas in batch mode? http://wiki.apache.org/cassandra/Operations#Repairing_missing_or_inconsistent_data -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
