kudu的副本数量是在表上设置，可以通过命令查看
# sudo -u kudu kudu cluster ksck $master
...
Summary by table
Name | RF | Status | Total Tablets | Healthy | Recovering | Under-replicated | Unavailable
----------------------------------------------------------+----+---------+---------------+---------+------------+------------------+-------------
impala::test_db.test_table | 3 | HEALTHY | 4 | 4 | 0 | 0 | 0
...
其中RF即replication factor；
副本数量只能在创建表时指定，创建后不能修改，并且副本数量必须为奇数
By default, Kudu tables created through Impala use a tablet replication factor of 3. To specify the replication factor for a Kudu table, add a TBLPROPERTIES clause to the CREATE TABLE statement as shown below where n is the replication factor you want to use:
A replication factor must be an odd number.
Changing the kudu.num_tablet_replicas table property using ALTER TABLE currently has no effect.
参考：
https://kudu.apache.org/docs/kudu_impala_integration.html