My hunch is the bigger your cluster the less impact it will have, as each node takes part in smaller and smaller % of total queries. Considering that compaction is always happening, I'd wager if you've got a big cluster (as you say you do) you'll probably be ok running several cleanups at a time.
I'd say start one, see how your perf is impacted (if at all) and go from there. If you're running a proper snitch you could probably do an entire rack / AZ at a time. On Thu, Oct 8, 2015 at 3:08 PM sai krishnam raju potturi < pskraj...@gmail.com> wrote: > We plan to do it during non-peak hours when customer traffic is less. That > sums up to 10 nodes a day, which is concerning as we have other data > centers to be expanded eventually. > > Since cleanup is similar to compaction, which is CPU intensive and will > effect reads if this data center were to serve traffic. Is running cleanup > in parallel advisable?? > > On Thu, Oct 8, 2015, 17:53 Jonathan Haddad <j...@jonhaddad.com> wrote: > >> Unless you're close to running out of disk space, what's the harm in it >> taking a while? How big is your DC? At 45 min per node, you can do 32 >> nodes a day. Diverting traffic away from a DC just to run cleanup feels >> like overkill to me. >> >> >> >> On Thu, Oct 8, 2015 at 2:39 PM sai krishnam raju potturi < >> pskraj...@gmail.com> wrote: >> >>> hi; >>> our cassandra cluster currently uses DSE 4.6. The underlying >>> cassandra version is 2.0.14. >>> >>> We are planning on adding multiple nodes to one of our datacenters. This >>> requires "nodetool cleanup". The "nodetool cleanup" operation takes >>> around 45 mins for each node. >>> >>> Datastax documentation recommends running "nodetool cleanup" for one >>> node at a time. That would be really long, owing to the size of our >>> datacenter. >>> >>> If we were to divert the read and write traffic away from a particular >>> datacenter, could we run "cleanup" on multiple nodes in parallel for >>> that datacenter?? >>> >>> >>> http://docs.datastax.com/en/cassandra/2.0/cassandra/operations/ops_add_node_to_cluster_t.html >>> >>> >>> thanks >>> Sai >>> >>
