Ok, thank you Ryan. I'm glad that what I'm seeing is expected behavior, although it is a little surprising.
As Kyle asked in a parallel reply on this thread: is it possible for the client to distinguish between these different scenarios where a notfound can be returned? My initial thought is that when a node is being added, clients can do reads with r=1 and retry GETs that 404...? On Monday, May 2, 2011 at 8:14 PM, Ryan Zezeski wrote: > Greg, > > Your expectations are fair, just because you added a node doesn't mean Riak > should return notfounds. Unfortunately, we aren't quite there yet. This is a > side effect of how Riak currently implements handoff in that it immediately > updates/gossips the ring causing many partitions to handoff immediately. If a > request comes in that relies on these partitions then it will get a notfound > and perform read repair. You're situation is multiplied by the fact that you > are going from 3 nodes to 4. More vnode shuffling occurs because of the small > cluster size. > > We're well aware of this and have it on our radar for improvement in a future > release. > > All this said, you data will be eventually consistent. That is, all your data > will eventually be handed off and things will work as normal. It's only > during the handoff that you _may_ encounter notfounds. In this case it would > be best to add a new node to your cluster at lowest load times and if you can > spare additional hardware a few more nodes to start with is an even easier > option. > > -Ryan > > On Mon, May 2, 2011 at 9:48 PM, Greg Nelson <gro...@dropcam.com> wrote: > > Hello riak users! > > > > I have a 4 node cluster that started out as 3 nodes. ring_creation_size = > > 2048, target_n_val is default (4), and all buckets have n_val = 3. > > > > When I joined the 4th node, for a few minutes some GETs were returning 'not > > found' for data that was already in riak. Eventually the data was returned, > > due to read repair I would assume. Is this expected? It seems that 'not > > found' and read repairs should only happen when something goes wrong, like > > a node goes down. Not when adding a node to the cluster, which is supposed > > to be part of normal operation! > > > > Any help or insight is appreciated! > > > > Greg > > _______________________________________________ > > riak-users mailing list > > riak-users@lists.basho.com > > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > > > >
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