IT mysqltest role and role2 failed

[aytrack]

Bug Report

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1. Minimal reproduce step (Required)

#30204 was change the login user identify
in ci https://ci.pingcap.net/blue/organizations/jenkins/tidb_ghpr_integration_common_test/detail/tidb_ghpr_integration_common_test/8049/pipeline

run test [role] err: sql:SHOW GRANTS FOR current_user() USING `replication`;: failed to run query 
SHOW GRANTS FOR current_user() USING `replication`;around line 216,
we need(291):
SHOW GRANTS FOR current_user() USING `replication`;
Grants for joe@localhost
GRANT USAGE ON *.* TO 'joe'@'localhost'
GRANT UPDATE ON role.* TO 'joe'@'localhost'
GRANT SELECT,DELETE ON role.t_external TO 'joe'@'localhost'
GRANT 'replication'@'%', 'wp_administrators'@'%' TO 'joe'@'localhost'
but got(291):
SHOW GRANTS FOR current_user() USING `replication`;
Grants for joe@127.0.0.1
GRANT USAGE ON *.* TO 'joe'@'localhost'
GRANT UPDATE ON role.* TO 'joe'@'localhost'
GRANT SELECT,DELETE ON role.t_external TO 'joe'@'localhost'
GRANT 'replication'@'%', 'wp_administrators'@'%' TO 'joe'@'localhost'\n\n"

run test [role2] err: sql:SHOW GRANTS FOR CURRENT_USER() USING r1;: failed to run query 
"SHOW GRANTS FOR CURRENT_USER() USING r1;\" \n around line 23, \nwe need(139):
SHOW GRANTS FOR CURRENT_USER() USING r1
Grants for u1@localhost
GRANT 'r1'@'%' TO 'u1'@'localhost'
GRANT USAGE ON *.* TO 'u1'@'localhost'
but got(139):
SHOW GRANTS FOR CURRENT_USER() USING r1;
Grants for u1@127.0.0.1
GRANT 'r1'@'%' TO 'u1'@'localhost'
GRANT USAGE ON *.* TO 'u1'@'localhost'"

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

[aytrack]

and this may lead to grant_dynamic failed because the u1@localhost already exists.

[2021-11-30T09:10:03.016Z] time="2021-11-30T17:10:02+08:00" level=error msg="run test [grant_dynamic] err: sql:CREATE USER 'u1'@'localhost' IDENTIFIED BY '123';: run \"CREATE USER 'u1'@'localhost' IDENTIFIED BY '123';\" at line 5 err Error 1396: Operation CREATE USER failed for 'u1'@'localhost'"

[bb7133]

Is this related to the concurrent execution of mysql test?

[morgo]

It is caused by an output difference:

• Grants for u1@localhost

• Grants for u1@127.0.0.1

Functionality is the same.

I'll take a look.

[github-actions]

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