I meant migrating to gosspsnitch during adding new dc. New dc will be empty so all the data will be streamed based on snitch property chosen
Sent from my iPhone > On Jun 7, 2018, at 12:23 PM, Jeff Jirsa <jji...@gmail.com> wrote: > > 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/201406.mbox/%3cca+vsrlopop7th8nx20aoz3as75g2jrjm3ryx119deklynhq...@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! >>>>> >>>>> >>>>> >>>> >>> >> >
