the optimal value of the ring_creation_size

Tom Zeng tom at
Mon Apr 22 17:30:45 EDT 2013

Ok thanks Joe.  We plan to switch to the Multi backend, so will use 512.

On Mon, Apr 22, 2013 at 5:17 PM, Joe Caswell <jcaswell at> wrote:

> Tom,
>   There is no hard and fast rule for the "best value."  The optimal value
> for your situation will need to take into account the physical resources
> available both in your starting cluster as well as your planned end-state
> cluster.  If you plan to use secondary indexing, the maximum
> ring_creation_size you should consider is 512.
>   There will be a separate concurrent vnode_proxy process for each vnode,
> and a process for each backend for each vnode.  Each backend will need open
> file handles and RAM for caching objects.  The backend configuration
> section of the docs should help plan your backed settings
>   Your planning must also include failure scenarios.  If any of your nodes
> crash, the surviving nodes will each start more vnodes to cover the missing
> node(s).   The 10 vnodes per node recommendation is to ensure that the
> vnodes from any single failed node can be divided among enough surviving
> nodes to not leave one node handling significantly more load than the
> other, but this also is not a hard and fast rule.
> At this time changing number of partitions in the ring does require a
> complete rebuild of the cluster,  we do have dynamic ring sizing on the
> product roadmap, but there is no release date set for that feature.
> Joe Caswell
> From: Tom Zeng <tom at>
> Date: Sunday, April 21, 2013 9:38 PM
> To: <riak-users at>
> Subject: the optimal value of the ring_creation_size
> Hi,
> I am wondering what's the best value for ring_creation_size, the default
> is 64. According to the docs 64 will work for a cluster of no more than 6
> nodes (64 /10), and ring_creation_size of 128 will allow cluster of up to
> 12 mode.  I am wondering what kind of overhead of is associated with a
> large ring_creation_size.  Since changing the ring_creation_size will
> result in rebuilding the cluster(destuctive), would a larger value make
> more sense and allow scaling by adding more nodes?
> Thanks,
> Tom
> --
> Tom Zeng
> Director of Engineering
> Intridea, Inc. |
> tom at
> (o) 888.968.4332 x519
> (c) 240-643-8728
> _______________________________________________ riak-users mailing list
> riak-users at
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