Jeff, In this case, if Riccardo is adding new DC, then he can pickup new snitch protocol right?
On Thu, Jun 7, 2018 at 12:15 PM, Jeff Jirsa <jji...@gmail.com> wrote: > > > > On Thu, Jun 7, 2018 at 9:12 AM, Nitan Kainth <nitankai...@gmail.com> > wrote: > >> 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. >> > > If you change the snitch, and the data ownership changes, you run the risk > of violating at least consistency guarantees, if not outright losing data. > > Changing the snitch is only something you should attempt if you understand > the implications. Cassandra does NOT re-stream data to the right places > if/when you change a snitch. > > > >> >> 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. >> > > This is very much workload dependent. I know of people running thousands > of nodes / petabytes of EBS on 4T GP2 volumes which provide 10k iops, and > they RARELY go above 1k iops during normal use patterns. > > - Jeff > > > >> >> 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/201 >>> 406.mbox/%3CCA+VSrLopop7Th8nX20aOZ3As75g2jrJm3ryX119dekLYNHq >>> f...@mail.gmail.com%3E - Thanks Alain RODRIGUEZ! >>> or here: >>> http://grokbase.com/t/cassandra/user/1498y74hn7/moving-cassa >>> ndra-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! >>> >>> >>> >>> >> >
