Hi Marco, Please see my responses inline below.
-- Hector On Thu, Feb 27, 2014 at 3:04 AM, Marco <ma...@mashape.com> wrote: > Hi everybody, > > I have a couple of questions regarding the performance requirements for a > 12TB Riak cluster, specifically: Have you taken the default replication factor of 3 here, or is this the sum of your data? > 1) I wonder if four servers, each one with the following spec, can handle > it: 6 cores at 2.20GHz (15MB cache), 16GB of memory, and two 3TB HDD in a > Raid 1 configuration. And if not, what would be the recommended number of > machines we should provision. These machines are physical machines. We > execute one or two M/R jobs per day, the scripts are written in Erlang. For production Riak deployments, we generally recommend a cluster with 5 nodes or greater. [0] Beyond that, some decisions around backend, overall capacity, and access patterns (anything outside of M/R) need to be taken into consideration before validating a set of hardware specifications. A high level guide of the decisions in the process are outlined here: - http://docs.basho.com/riak/latest/ops/building/planning/system-planning/ - http://docs.basho.com/riak/latest/ops/building/planning/cluster/ > 2) Since we have two HDD per server in a Raid 1 configuration, I also wonder > if we can safely set the replication factor to one, since the data is > already stored twice: if we lose an HDD, we still got the data on the other > one thanks to the Raid 1 conf. RAID 1 would cut your per node disk capacity in half (1.5TB), so at 4 nodes, your overall cluster capacity would only be 6TB. For the N=1 question, I guess the best way to answer it is that Riak maintains replicas within the system to facilitate high availability. Any node or disk outage (or even scheduled maintenance) is going to cause replicas to be unavailable in your cluster. This is generally not desirable in any clustered configuration. > Thanks [0] http://basho.com/why-your-riak-cluster-should-have-at-least-five-nodes/ > _______________________________________________ > 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
