Hbase region servers load balancing in a cluster with disparate nodes

[#1]

In our CDH 5.5 cluster, we have about 12 region servers nodes out of which 4 nodes are 8 cores and the remaining are 16 cores. We have noticed those 4 nodes are always busy during our load. Is it possible to assign weights to these low powered 4 nodes such that they will house let say 50% less regions compared to other set of nodes.

[#2 · Accepted solution]

Short Answer: No, not possible to balance with respect to cpu/memory resources out of the box today to my knowledge.

Longer Answer: You can write a custom balancer either external to hbase or using the hbase balancer protocol. Using the region_mover.rb as an example you can write your own jruby that can be run by the shell. Unfortunately, ultimately you will likely be better off without the underpowered nodes in the cluster than you are with them in.  Perhaps keep them in for HDFS storage and run just YARN there?