Tyler, Thanks for the explanation. The objective is not to have a perfectly balanced US-East and SG DC clusters. SG DC cluster is just a backup cluster and hence has lesser nodes than US-East cluster. What we are trying to figure out is the imbalance between the 6 nodes within US-East itself. I'll try to correct the 6 nodes with US-East to proper racks and check.
In addition, as I mentioned earlier, do you see any issues with the dynamic snitch attribute score? I see that node has high score, but what value of dynamic_snitch_badness_threshold should I set so that other replicas can get the traffic? ( that node has >50% higher score than all other nodes ) On Fri, Nov 1, 2013 at 10:04 PM, Tyler Hobbs <ty...@datastax.com> wrote: > > On Fri, Nov 1, 2013 at 5:07 AM, Rakesh Rajan <rakes...@gmail.com> wrote: > >> >> 1) By alternating racks, do you mean to alternate racks between all nodes >> in a single DC v/s multiple DCs? AWS EastCoast has 4 AZs >> and Singapore has 2 AZs. So is the final solution something like this: >> ip11 - East Coast - m1.xlarge / us-east-1b - Token: 0 >> ip21 - Singapore - m1.xlarge / ap-southeast-1a - Token: 1001 >> ip12 - East Coast - m1.xlarge / us-east-*1c* - >> Token: 28356863910078205288614550619314017621 >> ip13 - East Coast - m1.xlarge / us-east-*1d* - >> Token: 56713727820156410577229101238628035241 >> ip22 - Singapore - m1.xlarge / ap-southeast-1b - >> Token: 56713727820156410577229101238628036241 >> ip14 - East Coast - m1.xlarge / us-east-*1a* - >> Token: 85070591730234615865843651857942052863 >> ip15 - East Coast - m1.xlarge / us-east-*1b* - >> Token: 113427455640312821154458202477256070484 >> ip23 - Singapore - m1.xlarge / ap-southeast-*1a* - >> Token: 113427455640312821154458202477256071484 >> ip16 - East Coast - m1.xlarge / us-east-*1c* - >> Token: 141784319550391026443072753096570088105 >> >> Is this what you had suggested? >> > > That would be more balanced than your current setup, but it would still be > unbalanced, especially the ap-southeast DC. To have a perfectly balanced > cluster with multiple racks, you need to a) have the same number of nodes > on each rack, and b) alternate racks within each DC. Your new layout would > meet requirement (b), but not (a). This is why I suggest using the same > rack for all nodes. > > > -- > Tyler Hobbs > DataStax <http://datastax.com/> >
