Hbase quickly count number of rows

There are two ways  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

hbase shell

>count '<tablename>'

Example

>count 'employee'

6 row(s) in 0.1110 seconds

Use RowCounter in HBase RowCounter is in build 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.Its very helpfull when hbase table have huge data stored

Scenario #2
If hbase table size is large,then execute inbuilt RowCounter map reduce job: Login to hadoop machine with valid user and execute:
/$HBASE_HOME/bin/hbase org.apache.hadoop.hbase.mapreduce.RowCounter '<tablename>'
Example:
 /$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