large ring_creation_size

Alexander Sicular siculars at gmail.com
Wed May 16 21:07:10 EDT 2012


There are reasonable limits. And also for architecture. If I understand you correctly, yours is not reasonable. Although you have jbod's on each physical server does not mean you should run "12 riak nodes on a given physical node." there are other resource limits than just disk io. In this instance you are running into an os limitation in the number of file descriptors, aka max open files including sockets.

If you absolutely want to do it your way, which I absolutely do not recommend, I would run many virtual machines on top of each physical device from its own disk. But like I said, even then I wouldn't. 

Constructively, I think the largest recommended ring size is 1024 in practice. 

-Alexander 

@siculars on twitter
http://siculars.posterous.com

Sent from my iRotaryPhone

On May 16, 2012, at 20:47, Sam Lang <samlang at gmail.com> wrote:

> 
> Hello,
> 
> I have a 10 node cluster with 12 disks/devices per node.  I have setup riak in a jbod environment with separate riak nodes per device, resulting in 120 riak nodes total.  Based on the documentation, I set the ring_creation_size to 4096, which gives me ~34 partitions/node and allows me to expand the cluster in the future.  With this value, soon after starting the 12 riak nodes on a given physical node, I get "Too many processes" errors and the riak nodes fail.  Decreasing the value of ring_creation_size to 1024 (giving me ~8 partitions per riak node) prevents the riak nodes from failing, but then expanding the cluster becomes a problem (30 physical nodes would result in only ~3 partitions per node).
> 
> Is there a reasonable limit on the value of ring_creation_size?  
> _______________________________________________
> riak-users mailing list
> riak-users at lists.basho.com
> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com




More information about the riak-users mailing list