On May 11, 2010, at 10:07 AM, Germain Maurice wrote: > I'd like to know how works Riak when my bucket has n_val = 3 and only 2 > physical nodes. > Does Riak make 3 copies of the bucket over the 2 nodes or it maintains only 2 > copies of my bucket on the cluster ? > The data partitioning is done on they key level not the bucket level. An n_val of three will result in 3 vnodes/partitions holding replicas of the data. One of your nodes would control two of the three partitions.
> I'm doing tests of riak and i find some things weird. > > I have a two nodes cluster and a bucket with n_val = 3. > I put more than 1 600 000 documents in the bucket and it takes less than 200 > GB with Innostore. > I shut down the second node with "q()." in a "riak console". > Firstly, there was no synchronisation of data on the first node, i assume > it's better because very similar to a node crash. > Secondly, when i did a read request on a document with : > - ?r=1 -> success > - ?r=2 -> success > - ?r=3 -> fail This is due to the fact that 2 of the 3 vnodes were able to respond with your data, but not the third because your took down the node that had 1 of the 3 partitions. > > An other question, "n replicas" means "1 + n copies" or "n copies" of the > bucket ? > N replicas means N instances of the key will exist throughout the cluster. Grant Schofield Developer Advocate Basho Technologies > I really appreciate if you can explain me this behavior ? > > Thank you > Best Regards, > -- > Germain Maurice > Administrateur Système/Réseau > Tel : +33.(0)1.42.43.54.33 > > http://www.linkfluence.net > > > _______________________________________________ > riak-users mailing list > riak-users@lists.basho.com > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
