Hello, Please see comments under your
1) Use GossipingPropertyFileSnitc: http://www.datastax.com/documentation/cassandra/1.2/cassandra/architecture/architectureSnitchGossipPF_c.html - much easier to manage 2) All nodes in the same cluster must have the same cluster name: http://www.datastax.com/documentation/cassandra/1.2/cassandra/configuration/configCassandra_yaml_r.html 3) Run repair at the very end if you would like, rebuild should take care of this for you. No need to do it when you are going from Simple (with 1 DC) to Network (with 1 dc). Not sure you need to do step 2 actually. 4) Yes, all Keyspaces should be updated as a part of this process. Hope that helps. Jonathan Lacefield Solutions Architect, DataStax (404) 822 3487 <http://www.linkedin.com/in/jlacefield> <http://www.datastax.com/what-we-offer/products-services/training/virtual-training> On Sun, Mar 16, 2014 at 10:39 PM, Matthew Allen <matthew.j.al...@gmail.com>wrote: > Hi all, > > New to this list, so apologies in advance if I in inadvertently break some > of the guidelines. > > We currently have 2 geographically separate Cassandra/Application clusters > (running in active/warm-standby mode), that I am looking to enable > replication between so that we can have an active/active configuration. > > I've got the process working in our Labs, using > http://www.datastax.com/documentation/cassandra/1.2/cassandra/operations/ops_add_dc_to_cluster_t.htmlas > a guide, but still have many questions (to verify that what I have done > is correct), so I'm trying to break down my questions into various emails. > > Our Setup > --------------- > - Our replication factor is currently set to 5 in both sites (NSW and > VIC). Each site has 9 nodes. > - We use a read/write quorum of ONE > - We have autoNodeDiscovery set to off in our app ( in anticipation of > multi-site replication), so that it only points to its local Cassandra > cluster > - The 2 sites have a 16-20ms latency > > The Plan > ------------- > 1. Update and restart each node in active Cluster (NSW) 1 at a time to get > it to use NetworkTopologySnitch in preparation of addition of standby > cluster. > - update cassandra-topologies.yaml file with settings as below so NSW > Cluster is aware of NSW only > - update cassandra.yaml to use PropertyFileSnitch > - restart node > > # Cassandra Node IP=Data Center:Rack > xxx.yy.zzz.144=DC_NSW:rack1 > xxx.yy.zzz.145=DC_NSW:rack1 > xxx.yy.zzz.146=DC_NSW:rack1 > xxx.yy.zzz.147=DC_NSW:rack1 > xxx.yy.zzz.148=DC_NSW:rack1 > ... and so forth for 9 nodes > > 2. Update App Keyspace to use NetworkTopologySnitch with {'DC_NSW':5} > > 3. Stop and blow away the standby cluster (VIC) and start afresh, > - assign new tokens NSW+100 > - set auto_bootstrap: false > - update seeds to point to mixture of VIC and NSW nodes. > - update cassandra-topologies.yaml file with below so VIC Cluster is > aware of VIC and NSW. > - Leave cassandra cluster down > > # Cassandra Node IP=Data Center:Rack > xxx.yy.zzz.144=DC_NSW:rack1 > xxx.yy.zzz.145=DC_NSW:rack1 > xxx.yy.zzz.146=DC_NSW:rack1 > xxx.yy.zzz.147=DC_NSW:rack1 > xxx.yy.zzz.148=DC_NSW:rack1 > ... and so forth for 9 nodes > > aaa.bb.ccc.144=DC_VIC:rack1 > aaa.bb.ccc.145=DC_VIC:rack1 > aaa.bb.ccc.146=DC_VIC:rack1 > aaa.bb.ccc.147=DC_VIC:rack1 > aaa.bb.ccc.148=DC_VIC:rack1 > ... and so forth for 9 nodes > > 4. Update each node in active Cluster (NSW) 1 at a time. > - update cassandra-topologies.yaml file with settings as below so NSW > Cluster is aware of VIC and NSW. > > # Cassandra Node IP=Data Center:Rack > xxx.yy.zzz.144=DC_NSW:rack1 > xxx.yy.zzz.145=DC_NSW:rack1 > xxx.yy.zzz.146=DC_NSW:rack1 > xxx.yy.zzz.147=DC_NSW:rack1 > xxx.yy.zzz.148=DC_NSW:rack1 > ... and so forth for 9 nodes > > aaa.bb.ccc.144=DC_VIC:rack1 > aaa.bb.ccc.145=DC_VIC:rack1 > aaa.bb.ccc.146=DC_VIC:rack1 > aaa.bb.ccc.147=DC_VIC:rack1 > aaa.bb.ccc.148=DC_VIC:rack1 > ... and so forth for 9 nodes > > 5. Update App Keyspace to use NetworkTopologySnitch with > {'DC_NSW':5,'DC_VIC':5}. > > 6. Start standby cluster (VIC). > - run a nodetool rebuild on each node. > > Some questions > ----------------------- > - Does the Cluster Name on both clusters need to be the same ? > - Do I need to run a repair as part of Step 2 (after changing from Simple > to NetworkTopologyStrategy) ? > - Does the system keyspace snitch need to be updated to use > NetworkTopologyStrategy as well ? As currently in the Lab it display as > follows (please see 0.00% ownership below), or is this normal ? > - Can the different sites run different minor versions ? 1.2.9 <-> > 1.2.15, with a view to upgrading the other site to 1.2.15 ? > > System > Datacenter: DC_NSW > ========== > Address Rack Status State Load > Owns Token > > 0 > xxx.yy.zzz.65 rack1 Up Normal 433.42 KB > 50.00% -9223372036854775808 > xxx.yy.zzz.66 rack1 Up Normal 459.3 KB > 50.00% 0 > > > Datacenter: DC_VIC > ========== > Address Rack Status State Load > Owns Token > > 100 > aaa.bb.ccc.65 rack1 Up Normal 429.34 KB > 0.00% -9223372036854775708 > aaa.bb.ccc.66 rack1 Up Normal 391.3 KB > 0.00% 100 > > Thanks > > Matt >
