Daniel, See this post ( http://lists.basho.com/pipermail/riak-users_lists.basho.com/2017-August/019488.html) and the links in it for some more details on issues with the core claim algorithm. The fix is in the pending release 2.2.5 which Russell is adding the finishing touches to at the moment.
However, the fix may not immediately resolve your problem - the fix is about preventing this situation, not necessarily about resolving it once it has been created. Also the issue we saw that would lead to this, would not (I think) be triggered by adding a single node - unless the cluster already had the problem. So it is possible, although you are seeing the warning now, you had the issue when your originally created the cluster, and the change is just persisting the issue. For instance going from nothing straight to a 6-node with a ring-size of 128 would create this problem. As a workaround there is the core claim v3 algorithm which can be turned on, and you can see if this offers a better cluster plan without violations. I can't right now remember how to trigger v3 claim algorithm though - google letting me down. Ultimately, this may not be such a crisis. The error is through whenever the cluster cannot guarantee a "target_n_val" of 4. So if you have an n_val of 3 - you're not necessarily at risk of data loss. To know you will have to look at your ring via riak attach (see bullet point 2 in http://docs.basho.com/riak/kv/2.2.3/using/running-a- cluster/#add-a-second-node-to-your-cluster). If you can figure out the violations from your ring, you may be able to resolve by leaving the node that has the violations, and then re-adding it. Sorry, I'm a bit rushed - but I hope this helps get you started. Martin On 14 December 2017 at 19:49, Daniel Miller <dmil...@dimagi.com> wrote: > I have a 6 node cluster (now 7) with ring size 128. On adding the most > recent node I got the WARNING: Not all replicas will be on distinct nodes. > After the initial plan I ran the following sequence many times, but always > got the same plan output: > > sudo riak-admin cluster clear && \ > sleep 10 && \ > sudo service riak start && \ > sudo riak-admin wait-for-service riak_kv && \ > sudo riak-admin cluster join riak@hqriak20.internal && \ > sudo riak-admin cluster plan > > > The plan looked the same every time, and I eventually committed it because > the cluster capacity is running low: > > > Success: staged join request for 'riak@riak29.internal' to > 'riak@riak20.internal' > =============================== Staged Changes > ================================ > Action Details(s) > ------------------------------------------------------------ > ------------------- > join 'riak@riak29.internal' > ------------------------------------------------------------ > ------------------- > > > NOTE: Applying these changes will result in 1 cluster transition > > ############################################################ > ################### > After cluster transition 1/1 > ############################################################ > ################### > > ================================= Membership > ================================== > Status Ring Pending Node > ------------------------------------------------------------ > ------------------- > valid 17.2% 14.1% 'riak@riak20.internal' > valid 17.2% 14.8% 'riak@riak21.internal' > valid 16.4% 14.1% 'riak@riak22.internal' > valid 16.4% 14.1% 'riak@riak23.internal' > valid 16.4% 14.1% 'riak@riak24.internal' > valid 16.4% 14.8% 'riak@riak28.internal' > valid 0.0% 14.1% 'riak@riak29.internal' > ------------------------------------------------------------ > ------------------- > Valid:7 / Leaving:0 / Exiting:0 / Joining:0 / Down:0 > > WARNING: Not all replicas will be on distinct nodes > > Transfers resulting from cluster changes: 18 > 2 transfers from 'riak@riak28.internal' to 'riak@riak29.internal' > 3 transfers from 'riak@riak21.internal' to 'riak@riak29.internal' > 3 transfers from 'riak@riak23.internal' to 'riak@riak29.internal' > 3 transfers from 'riak@riak24.internal' to 'riak@riak29.internal' > 4 transfers from 'riak@riak20.internal' to 'riak@riak29.internal' > 3 transfers from 'riak@riak22.internal' to 'riak@riak29.internal' > > > My understanding is that if some replicas are not on distinct nodes then I > may have permanent data loss if a single physical node is lost (please let > me know if that is not correct). Questions: > > How do I diagnose which node(s) have duplicate replicas? > What can I do to fix this situation? > > Thanks! > Daniel > > > P.S. I am unable to get anything useful out of `riak-admin diag`. It > appears to be broken on the version of Riak I'm using (2.2.1). Here's the > output I get: > > $ sudo riak-admin diag > RPC to 'riak@hqriak20.internal' failed: {'EXIT', > {undef, > [{lager, > > get_loglevels, > [],[]}, > > {riaknostic,run, > 1, > [{file, > > "src/riaknostic.erl"}, > > {line,118}]}, > {rpc, > > '-handle_call_call/6-fun-0-', > 5, > [{file, > > "rpc.erl"}, > > {line,205}]}]}} > > _______________________________________________ > riak-users mailing list > riak-users@lists.basho.com > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > > -- ***** Email confidentiality notice ***** This message is private and confidential. If you have received this message in error, please let us know and remove it from your system.
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