> > > So if you have a topology that would change if you switched from >> SimpleStrategy to NetworkTopologyStrategy plus multiple racks, it sounds >> like a different migration strategy would be needed? >> >> I am imagining: >> >> 1. Switch to a different snitch, and the keyspace from SimpleStrategy >> to NTS but keep it all in one rack. So effectively the same topology, but >> with a different snitch. >> 2. Set up a new data centre with the desired topology. >> 3. Change the keyspace to have replicas in the new DC. >> 4. Rebuild all the nodes in the new DC. >> 5. Flip all your clients over to the new DC. >> 6. Decommission your original DC. >> >> That would work, yes. I would add : > > - 4.5. Repair all nodes. >
I can confirm that the above process works (definitely include Rob's repair suggestion, though). It is really the only way we've found to safely go from SimpleSnitch to rack-aware NTS. The same process works/is required for SimpleSnitch to Ec2Snitch fwiw. -- ----------------- Nate McCall Austin, TX @zznate Co-Founder & Sr. Technical Consultant Apache Cassandra Consulting http://www.thelastpickle.com
