Let's try to find a way to move MTA to hbase-server. Putting it in hbase-balancer is a bit weird (Why is the MetaTableAccessor in the balancer module?).
MetaTableAccessor (MTA) is in hbase-balancer because the favored nodes (FN) feature wants to write to meta.
The FN feature (
HBASE-7932 which arrived in hbase-0.96.0) I believe is unused. The idea of maintaining locality across a crash is a good one but having to enable a different balancer to default to enable FN operation has made it so the feature has been let rot. HBASE-21014 makes an appeal for integrating FN into the default stochastic balancer. HBASE-15531 is an old effort that actually tried to integrate FN into stochastic balancer but stalled out.