> > But one more question, should i use num_tokens : 8 (i would follow > datastax recommendation) and allocate_tokens_for_local_replication_factor=3 > (which is max RF among my keyspaces) for new clusters which i'm going to > setup?
16 is probably where it's at. Test beforehand though. > Is the Allocation algorithm, now recommended algorithm and mature enough > to replace the Random algorithm? if its so, it should be the default one at > 4.0? Let's leave that discussion to the other thread on the dev list. On Sat, 22 Sep 2018 at 20:35, onmstester onmstester <onmstes...@zoho.com> wrote: > Thanks, > Because all my clusters are already balanced, i won't change their config > But one more question, should i use num_tokens : 8 (i would follow > datastax recommendation) and allocate_tokens_for_local_replication_factor=3 > (which is max RF among my keyspaces) for new clusters which i'm going to > setup? > Is the Allocation algorithm, now recommended algorithm and mature enough > to replace the Random algorithm? if its so, it should be the default one at > 4.0? > > > ---- On Sat, 22 Sep 2018 13:41:47 +0330 *kurt greaves > <k...@instaclustr.com <k...@instaclustr.com>>* wrote ---- > > If you have problems with balance you can add new nodes using the > algorithm and it'll balance out the cluster. You probably want to stick to > 256 tokens though. > To reduce your # tokens you'll have to do a DC migration (best way). Spin > up a new DC using the algorithm on the nodes and set a lower number of > tokens. You'll want to test first but if you create a new keyspace for the > new DC prior to creation of the new nodes with the desired RF (ie. a > keyspace just in the "new" DC with your RF) then add your nodes using that > keyspace for allocation tokens *should* be distributed evenly amongst > that DC, and when migrate you can decommission the old DC and hopefully end > up with a balanced cluster. > Definitely test beforehand though because that was just me theorising... > > I'll note though that if your existing clusters don't have any major > issues it's probably not worth the migration at this point. > > On Sat, 22 Sep 2018 at 17:40, onmstester onmstester <onmstes...@zoho.com> > wrote: > > > I noticed that currently there is a discussion in ML with > subject: changing default token behavior for 4.0. > Any recommendation to guys like me who already have multiple clusters ( > > 30 nodes in each cluster) with random partitioner and num_tokens = 256? > I should also add some nodes to existing clusters, is it possible > with num_tokens = 256? > How could we fix this bug (reduce num_tokens in existent clusters)? > Cassandra version: 3.11.2 > > Sent using Zoho Mail <https://www.zoho.com/mail/> > > > >
