DCs can be stood up with snapshotted data.
Stand up a new cluster with your old cluster snapshots: https://docs.datastax.com/en/cassandra/2.1/cassandra/operations/ops_snapshot_restore_new_cluster.html Then link the DCs together. Disclaimer: I've never done this in real life. On Wed, Feb 21, 2018 at 9:25 AM, Nitan Kainth <nitankai...@gmail.com> wrote: > New dc will be faster but may impact cluster performance due to streaming. > > Sent from my iPhone > > On Feb 21, 2018, at 8:53 AM, Leena Ghatpande <lghatpa...@hotmail.com> > wrote: > > We do use LOCAL_ONE and LOCAL_Quorum currently. But these 8 nodes need to > be in 2 different DC< so we would end up create additional 2 new DC and > dropping 2. > > are there any advantages on adding DC over one node at a time? > > > ------------------------------ > *From:* Jeff Jirsa <jji...@gmail.com> > *Sent:* Wednesday, February 21, 2018 1:02 AM > *To:* user@cassandra.apache.org > *Subject:* Re: Best approach to Replace existing 8 smaller nodes in > production cluster with New 8 nodes that are bigger in capacity, without a > downtime > > You add the nodes with rf=0 so there’s no streaming, then bump it to rf=1 > and run repair, then rf=2 and run repair, then rf=3 and run repair, then > you either change the app to use local quorum in the new dc, or reverse the > process by decreasing the rf in the original dc by 1 at a time > > -- > Jeff Jirsa > > > > On Feb 20, 2018, at 8:51 PM, Kyrylo Lebediev <kyrylo_lebed...@epam.com> > wrote: > > > > I'd say, "add new DC, then remove old DC" approach is more risky > especially if they use QUORUM CL (in this case they will need to change CL > to LOCAL_QUORUM, otherwise they'll run into a lot of blocking read repairs). > > Also, if there is a chance to get rid of streaming, it worth doing as > usually direct data copy (not by means of C*) is more effective and less > troublesome. > > > > Regards, > > Kyrill > > > > ________________________________________ > > From: Nitan Kainth <nitankai...@gmail.com> > > Sent: Wednesday, February 21, 2018 1:04:05 AM > > To: user@cassandra.apache.org > > Subject: Re: Best approach to Replace existing 8 smaller nodes in > production cluster with New 8 nodes that are bigger in capacity, without a > downtime > > > > You can also create a new DC and then terminate old one. > > > > Sent from my iPhone > > > >> On Feb 20, 2018, at 2:49 PM, Kyrylo Lebediev <kyrylo_lebed...@epam.com> > wrote: > >> > >> Hi, > >> Consider using this approach, replacing nodes one by one: > https://mrcalonso.com/2016/01/26/cassandra-instantaneous-in- > place-node-replacement/ > > <https://mrcalonso.com/2016/01/26/cassandra-instantaneous-in-place-node-replacement/> > Cassandra instantaneous in place node replacement | Carlos ... > <https://mrcalonso.com/2016/01/26/cassandra-instantaneous-in-place-node-replacement/> > mrcalonso.com > At some point everyone using Cassandra faces the situation of having to > replace nodes. Either because the cluster needs to scale and some nodes are > too small or ... > > >> > >> Regards, > >> Kyrill > >> > >> ________________________________________ > >> From: Leena Ghatpande <lghatpa...@hotmail.com> > >> Sent: Tuesday, February 20, 2018 10:24:24 PM > >> To: user@cassandra.apache.org > >> Subject: Best approach to Replace existing 8 smaller nodes in > production cluster with New 8 nodes that are bigger in capacity, without a > downtime > >> > >> Best approach to replace existing 8 smaller 8 nodes in production > cluster with New 8 nodes that are bigger in capacity without a downtime > >> > >> We have 4 nodes each in 2 DC, and we want to replace these 8 nodes with > new 8 nodes that are bigger in capacity in terms of RAM,CPU and Diskspace > without a downtime. > >> The RF is set to 3 currently, and we have 2 large tables with upto > 70Million rows > >> > >> What would be the best approach to implement this > >> - Add 1 New Node and Decomission 1 Old node at a time? > >> - Add all New nodes to the cluster, and then decommission old nodes ? > >> If we do this, can we still keep the RF=3 while we have 16 nodes > at a point in the cluster before we start decommissioning? > >> - How long do we wait in between adding a Node or decomissiing to > ensure the process is complete before we proceed? > >> - Any tool that we can use to monitor if the add/decomission node is > done before we proceed to next > >> > >> Any other suggestion? > >> > >> > >> --------------------------------------------------------------------- > >> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > >> For additional commands, e-mail: user-h...@cassandra.apache.org > >> > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > > For additional commands, e-mail: user-h...@cassandra.apache.org > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > > For additional commands, e-mail: user-h...@cassandra.apache.org > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > >
