Actually, I just found this bug: https://issues.basho.com/show_bug.cgi?id=992
So it looks like the r=1 idea won't work. On Monday, May 2, 2011 at 8:36 PM, Greg Nelson wrote: > 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 <[email protected]> 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 > > > [email protected] > > > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > > > > > > > >
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