On Monday, March 7, 2011 at 7:57 AM, Sylar Shen wrote: Yes, an odd number is the best practice. > What I concerned is that the numbers of monitors when the scalability > gets bigger. > For now, I think 3 is OK, too. But I will have more servers to be > added in the future(more than 100 servers). That's unlikely to be a problem for you. The monitors don't have too handle too many messages; they handle the cluster state but generally each OSD is going to send them (small) messages a couple times a second -- or possibly much less often. > And I would like to know the proportions of each role(MDS,OSD,MON) in a cluster. Because in the future, we will have more servers to build and test. 3 monitors should be sufficient for any cluster you are likely to build (I don't know what he maximum is, but it's a lot). Configurations with 1 MDS are a lot more stable than configurations with multiple MDSes, so I'd start with that and if you find that you need to handle more metadata ops, you can add more -- adding MDSes to a running cluster is fairly simple. And put in all the OSDs you need to handle your storage size and bandwidth needs! :) -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
