Using HBase scanner heartbeat
A scanner heartbeat check enforces a time limit on the execution of scan RPC requests. This helps prevent scans from taking too long and causing a timeout at the client.
When the server receives a scan RPC request, a time limit is calculated
to be half of the smaller of two values:
hbase.rpc.timeout (which both default to 60000
milliseconds, or one minute). When the time limit is reached, the server
returns the results it has accumulated up to that point. This result set
may be empty. If your usage pattern includes that scans will take longer
than a minute, you can increase these values.
To make sure the timeout period is not too
short, you can configure
hbase.cells.scanned.per.heartbeat.check to a minimum
number of cells that must be scanned before a timeout check occurs. The
default value is 10000. A smaller value causes timeout checks to occur