There is a new commit to YCSB:
This fixes performance problems in the HBase DB adapter. In my own
tests I found that my short scans, which were configured to read
100-column rows, 1-300 in zipfian, went from 60ms to 35ms.
Also there is column selection pushdown enabled, which will improve
the speed of any tests that are doing single column gets on a wide row
(eg: readallfields=false, fieldcount=X).
This is all due to changing how YCSB uses the Result object. Check
out the commit for some hints. I have a longer email and patch about
this stuff coming really soon.