HBASE-12604 Backport HBASE-12128 (Cache configuration and RpcController selection for Table in Connection) to 0.98
HBASE-12631 Backport HBASE-12576 (Add metrics for rolling the HLog if there are too few DNs in the write pipeline) to 0.98
Update POM and CHANGES.txt for 0.98.9
Merge remote-tracking branch 'remotes/origin/0.98' into 0.98