Hbase quickly count number of rows

Question

Right now I implement row count over ResultScanner like this

for (Result rs = scanner.next(); rs != null; rs = scanner.next()) {
    number++;
}         


        

Answer 1

Two ways Worked for me to get count of rows from hbase table with Speed

Scenario #1

If hbase table size is small then login to hbase shell with valid user and execute

>count ''

Example

>count 'employee'

6 row(s) in 0.1110 seconds

Scenario #2

If hbase table size is large,then execute inbuilt RowCounter map reduce job: Login to hadoop machine with valid user and execute:

/$HBASE_HOME/bin/hbase org.apache.hadoop.hbase.mapreduce.RowCounter ''

Example:

 /$HBASE_HOME/bin/hbase org.apache.hadoop.hbase.mapreduce.RowCounter 'employee'

     ....
     ....
     ....
     Virtual memory (bytes) snapshot=22594633728
                Total committed heap usage (bytes)=5093457920
        org.apache.hadoop.hbase.mapreduce.RowCounter$RowCounterMapper$Counters
                ROWS=6
        File Input Format Counters
                Bytes Read=0
        File Output Format Counters
                Bytes Written=0