I don't know about "new snitch protocol" (there is no snitch protocol), but in the case of ec2snitch and gossipingpropertyfilesnitch (do not extrapolate this to any other combination), you can switch them 1:1 before the move, and everything should be fine, as long as care is taken to make the property file match the aws region/az discovered.
If there were other snitches involved (especially SimpleSnitch), things get much more complicated. On Thu, Jun 7, 2018 at 9:18 AM, Nitan Kainth <nitankai...@gmail.com> wrote: > 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! >>>> >>>> >>>> >>>> >>> >> >
