Here is a heads up on some work I've been doing of late. My goal is to make region assignment simpler, faster, more reliable
and maintainable making it so we are able to handle many more regions
more efficiently (improve mttr, and lessen impact of compactions), and
to eventually look into quorum-based master service.
In HBASE-10569, I posted a patch that makes a HMaster also a HRegionServer. I've also done work so that we can co-locate the meta region with the master server. These changes are based on one of the agreements per the discussion in HBASE-5487, the master re-design.
We should be able to do a rolling restart on to this new basis (I'm
working on it).
Putting the master and regionserver processes together and making it
so meta and master are also together is a step toward making it easier doing region assignment without using ZK, another agreement from HBASE-5487. Thanks.