Here's my understanding for best practices around cluster rebalancing using DSE & opscenter
1. Initial setup- The first time you are setting up a cluster, with known plan for data centers and number of nodes, calculate initial tokens using token generating tool and set it in the yaml files. Bring up a balanced cluster
2. Expanding capacity- Once the cluster is live, and you want to add one or 2 nodes to increase capacity, you can leave the initial token blank. Cassandra will assign it a token so that it bisects the heaviest loaded nodes token range. To make it perfectly balanced, use opscenter rebalance.
Question -
1. Will it internally cater for different scenarios like doubling the capacity of the ring etc as mentioned in Calculating Tokens For the New Nodes section of this link http://www.datastax.com/docs/1.0/operations/cluster_management
Will it attempt to have the least number of changes in token required ?
2. Will it internally do nodetool move tokens & nodetool cleanup wherever required?
3. Will nodetool cleanup happen simultaneously or at a later time when the load is lower?
3. Removing capacity- Once the cluster is live, and you want to remove nodes, you choose decommision node in opscenter.
Question
1. will this automatically result in a balanced cluster, or do you need to do a Rebalance explicitly?
For scenarios 2 and 3 the other options are to do nodetool commands like move and cleanup manually. Do we lose any flexibility or performance benefits by using opscenter rebalance ?
