grant drop database on db1 to user1, drop database failed, but drop database on cluster ok

[qmdt]

Hi， When I try to figure out the drop privilege of clickhouse cluster ,I find that a user could not drop database with tables in it with "drop database" privilege,the server returns error said "DB::Exception: user1: Not enough privileges. To execute this query it's necessary to have grant DROP TABLE ON db1.testtb1". But when excute the drop database SQL with "on cluster", it did work, which means the tables in the database are dropped too. I think thats strange. my steps are below:

1.# create role create role1 on cluster default_cluster;

2. create user

   create user1 on cluster default_cluster;

3. create database

   create database db1 on cluster default_cluster;

4. create table

   CREATE TABLE db1.testtb1 ( id String, price Float64, create_time DateTime ) ENGINE = ReplicatedMergeTree('/clickhouse/db1/tables/{shard}/testtb1', '{replica}') PARTITION BY toYYYYMM(create_time) ORDER BY id SETTINGS index_granularity = 8192

5. grant drop database privilege to role

   grant drop database to role1 on cluster default_cluster;

6. grant role to user

   grant role1 to user1 on cluster default_cluster;

7. login one of the servers in the cluster with user1,and excute the drop command: drop database db1;

and the results were : Received exception from server (version 21.3.4): Code: 497. DB::Exception: Received from xxxxx DB::Exception: user1: Not enough privileges. To execute this query it's necessary to have grant DROP TABLE ON db1.testtb1.

8.excute the command with "on cluster" : drop database db1 on cluster default_cluster;

it works,the database db1 and the table testtb1 are all dropped on any server of the cluster. I think this is strange， if it can‘t be excuted on one server ,how could it be excuted on cluster ? As I did in my steps, the "drop database" privilege should be the same on all server，I think step8 should have the same result as step7.

my clickhouse version is 21.3.4,I use the tcp interface,all default settings, THANKS FOR ANY HELP.

[qmdt]

Is there anyone who can explain this ? thanks