I think your request is described in https://issues.apache.org/jira/browse/HBASE-3373
Practically speaking, the scenario below can hardly occur (in trunk, at least). If the tables are created with pre-split regions, the regions would be round-robin distributed. If the tables are created with single region, subsequent write operations would cause the region split. Balancer would offload young regions to other servers - see HBASE-3609 <https://issues.apache.org/jira/browse/HBASE-3609>which is not in 0.90 branch. Refer to http://zhihongyu.blogspot.com/2011/04/load-balancer-in-hbase-090.html for details. Cheers On Fri, May 20, 2011 at 12:25 AM, Schubert Zhang <[email protected]> wrote: > I have a question about HBase balancer. > > In release 0.90.x, it seems the balancer only regards the number of regions > and balance these regions into every regionserver. > > If we have two tables (A and B) now, each have 100 regions. > Then, a extreme situation is: > > RegionsServer1: 100 regions, which all belong to table A > RegionsServer2: 100 regions, which all belong to table B > > If my application access table B heavy, the almost all opetations hit > RegionsServer2, it is not balance. > > I have a idea about the balance policy: > (1) Firstly balance for each table > (2) Then, overall balance. > > > Schubert >
