Hi Cyril, it will depend on the load balancing policy that is used in the client code.
If you're only accessing DC1, with the node being rebuilt living in DC2, then you need your clients to be using the DCAwareRoundRobinPolicy to restrict connections to DC1 and avoid all kind of queries hitting DC2. If clients are accessing both datacenters, and you're not using the TokenAwarePolicy, even with LOCAL_ONE, the coordinator could pick the node being rebuilt to process the query. If you're not spinning up a new datacenter in an existing cluster, rebuilding a node is not the best way to achieve this without compromising consistency. The node should be replaced, which will make it bootstrap safely (he can replace himself, using the "-Dcassandra.replace_address_first_boot=<address_of_replaced_node>" flag. Bootstrap lets the node stream the data it needs faster than repair would, while keeping it out of read requests. The procedure is to stop Cassandra, wipe data, commit log and saved caches, and then restart it with the JVM flag set in cassandra-env.sh. The node will appear as joining or down while bootstrapping (it depends if it replaces itself or another node, can't remember the specifics). If it shows up as down, it will rely on hints to get the writes. If it shows as joining, it will get the writes while streaming is ongoing. Cheers, ----------------- Alexander Dejanovski France @alexanderdeja Consultant Apache Cassandra Consulting http://www.thelastpickle.com On Tue, Aug 6, 2019 at 12:03 PM Cyril Scetbon <cyril.scet...@free.fr> wrote: > Can you elaborate on that ? We use GPFS > without cassandra-topology.properties. > — > Cyril Scetbon > > On Aug 5, 2019, at 11:23 PM, Jeff Jirsa <jji...@gmail.com> wrote: > > some snitch trickery (setting the badness for the rebuilding host) via jmx > > >
