Riccardo, Simplest method can be is to add VPC as an additional datacenter to existing cluster; once New DC has synced up all data, just switch over your application. Only caveat is that there should be enough network bandwidth between EC2 and VPC.
Horizontal scaling will help to some extent. Changing snitch will cause data movement but for new DC, I believe you can chose. Leaving others comment. With EBS, use right instance where IOPs are as high as possible. Generally, SSDs IOPs are 75K; what is best for you depends on workload. I have seen 20K IOPs supporting production loads in reasonable cluster. On Thu, Jun 7, 2018 at 6:20 AM, Riccardo Ferrari <ferra...@gmail.com> wrote: > Dear list, > > We have a small cluster on AWS EC2-Classic and we are planning to move it > to a VPC. > > I know this has been discussed few times already including here: > https://mail-archives.apache.org/mod_mbox/cassandra-user/ > 201406.mbox/%3CCA+VSrLopop7Th8nX20aOZ3As75g2jrJm > 3ryx119deklynhq...@mail.gmail.com%3E - Thanks Alain RODRIGUEZ! > or here: > http://grokbase.com/t/cassandra/user/1498y74hn7/moving-cassandra-from-ec2- > classic-into-vpc - Thanks Ben Bromhead! > > However I can't find anyone suggesting ClassicLink to perform such > migration, maybe because was recent addition compared to those posts. So > current status is: > > > - 3 nodes : m1.xlarge (ephemeral storage) > - Cassandra 3.0.8 > - Few keyspaces with {'class': 'SimpleStrategy', 'replication_factor': > '3'} > - endpoint_snitch: Ec2Snitch > - connectivity on private ips (local_address, rpc_address, no > broadcast_address) > - average load pretty high (we need to scale up) > - vnodes > > My idea is to migrate: > > - Add intances on to the existing cluster (1 by 1): > - Same cassandra version > - Same cluster name > - Seed list from ec2 classic list > - Run repair and cleanup > - Update seed list (cassandar config and services) > - Decommision old instances (1 by 1) > - Run repair and cleanup again > > > Question time: > > - What is the best approach, in 2018, for migrating a cluster from > EC2Classic to VPC with 0 downtime? > - Should we scale up before or during the migration? I know I should > expect some load from data streaming, at the same time we're adding > capacity. > - We would like to migrato to GossipingPropertyFileSnitch, can we mix > them? > - Any gothca? > - We are thinking to move to EBS (due to cluster size and snapshotting > caoabilities). Any hardware reccomendation? > > Any suggestion is much appreciated! > > > >
