Right now I implement row count over ResultScanner like this
ResultScanner
for (Result rs = scanner.next(); rs != null; rs = scanner.next()) { number++; }
To count the Hbase table record count on a proper YARN cluster you have to set the map reduce job queue name as well:
hbase org.apache.hadoop.hbase.mapreduce.RowCounter -Dmapreduce.job.queuename= < Your Q Name which you have SUBMIT access> < TABLE_NAME>