Exec class has a field: "private Configuration conf = HBaseConfiguration.create()"
Client side generates an Exec instance of the class, each initiated Statistics request by ExecRPCInvoker
Is so HBaseConfiguration.create for each request needs to call
When the server side deserialize the Exec Called once HBaseConfiguration.create in,
HBaseConfiguration.create is a time consuming operation.
"private Configuration conf = HBaseConfiguration.create()";
This code is only useful for testing code (org.apache.hadoop.hbase.coprocessor.TestCoprocessorEndpoint.testExecDeserialization),
other places with the Exec class, pass a Configuration come,
so no need to "conf" field a default value.