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

Use RowCounter in HBase RowCounter is a mapreduce job to count all the rows of a table. This is a good utility to use as a sanity check to ensure that HBase can read all the blocks of a table if there are any concerns of metadata inconsistency. It will run the mapreduce all in a single process but it will run faster if you have a MapReduce cluster in place for it to exploit.

$ hbase org.apache.hadoop.hbase.mapreduce.RowCounter 

Usage: RowCounter [options] 
     [          
        --starttime=[start] 
        --endtime=[end] 
        [--range=[startKey],[endKey]] 
        [ ...]
    ]