Sorry that only applies our you're using NTS. You're right that simple strategy won't work very well in this case. To migrate you'll likely need to do a DC migration to ensuite no downtime, as replica placement will change even if RF stays the same.
On 15 Sep. 2017 08:26, "kurt greaves" <k...@instaclustr.com> wrote: > If you have racks configured and lose nodes you should replace the node > with one from the same rack. You then need to repair, and definitely don't > decommission until you do. > > Also 40 nodes with 256 vnodes is not a fun time for repair. > > On 15 Sep. 2017 03:36, "Dominik Petrovic" <dominik.petro...@mail.ru.invalid> > wrote: > >> @jeff, >> I'm using 3 availability zones, during the life of the cluster we lost >> nodes, retired others and we end up having some of the data >> written/replicated on a single availability zone. We saw it with nodetool >> getendpoints. >> Regards >> >> >> Thursday, September 14, 2017 9:23 AM -07:00 from Jeff Jirsa < >> jji...@gmail.com>: >> >> With one datacenter/region, what did you discover in an outage you think >> you'll solve with network topology strategy? It should be equivalent for a >> single D.C. >> >> -- >> Jeff Jirsa >> >> >> On Sep 14, 2017, at 8:47 AM, Dominik Petrovic < >> dominik.petro...@mail.ru.INVALID> wrote: >> >> Thank you for the replies! >> >> @jeff my current cluster details are: >> 1 datacenter >> 40 nodes, with vnodes=256 >> RF=3 >> What is your advice? is it a production cluster, so I need to be very >> careful about it. >> Regards >> >> >> Thu, 14 Sep 2017 -2:47:52 -0700 from Jeff Jirsa <jji...@gmail.com>: >> >> The token distribution isn't going to change - the way Cassandra maps >> replicas will change. >> >> How many data centers/regions will you have when you're done? What's your >> RF now? You definitely need to run repair before you ALTER, but you've got >> a bit of a race here between the repairs and the ALTER, which you MAY be >> able to work around if we know more about your cluster. >> >> How many nodes >> How many regions >> How many replicas per region when you're done? >> >> >> >> >> -- >> Jeff Jirsa >> >> >> On Sep 13, 2017, at 2:04 PM, Dominik Petrovic < >> dominik.petro...@mail.ru.INVALID> wrote: >> >> Dear community, >> I'd like to receive additional info on how to modify a keyspace >> replication strategy. >> >> My Cassandra cluster is on AWS, Cassandra 2.1.15 using vnodes, the >> cluster's snitch is configured to Ec2Snitch, but the keyspace the >> developers created has replication class SimpleStrategy = 3. >> >> During an outage last week we realized the discrepancy between the >> configuration and we would now fix the issue using NetworkTopologyStrategy. >> >> What are the suggested steps to perform? >> For Cassandra 2.1 I found only this doc: http://docs.datastax.com/ >> en/cassandra/2.1/cassandra/operations/opsChangeKSStrategy.html >> that does not mention anything about repairing the cluster >> >> For Cassandra 3 I found this other doc: https://docs.datastax.com >> /en/cassandra/3.0/cassandra/operations/opsChangeKSStrategy.html >> That involves also the cluster repair operation. >> >> On a test cluster I tried the steps for Cassandra 2.1 but the token >> distribution in the ring didn't change so I'm assuming that wasn't the >> right think to do. >> I also perform a nodetool repair -pr but nothing changed as well. >> Some advice? >> >> -- >> Dominik Petrovic >> >> >> >> -- >> Dominik Petrovic >> >> >> >> -- >> Dominik Petrovic >> >
