ApsaraDB RDS:Use the session management feature

A percent sign (%) appears in the Access Source column when a session runs through a stored procedure. To reproduce this behavior:

1. In the ApsaraDB RDS console, create a database and a standard account, then grant permissions on the database to the standard account. For details, see Create an account.

2. Connect to the instance using the test_user account through the CLI. For details, see Use a client or the CLI to connect to an ApsaraDB RDS for MySQL instance.

3. Switch to the testdb database and create a stored procedure:

      -- Switch to the testdb database.
      USE testdb;
   
      -- Create a stored procedure.
      DELIMITER $$
      DROP PROCEDURE IF EXISTS `das` $$
      CREATE DEFINER=`test_user`@`%` PROCEDURE `das`()
      BEGIN
      SELECT * FROM information_schema.processlist WHERE Id = CONNECTION_ID();
      END $$
      DELIMITER;

4. Connect to the instance using a privileged account. For details, see Step 2: Connect to an ApsaraDB RDS for MySQL instance.

5. Call the stored procedure.

   Expected output: The HOST column displays %:2065 because the stored procedure was defined with DEFINER='test_user'@'%', and the session inherits this host value when the procedure runs under a privileged account.

      -- Switch to the testdb database.
      USE testdb;
   
      -- Call the stored procedure.
      CALL das();

      +--------+-----------+--------+--------+---------+------+-----------+-------------------------------------------------------------------------+
      | ID     | USER      | HOST   | DB     | COMMAND | TIME | STATE     | INFO                                                                    |
      +--------+-----------+--------+--------+---------+------+-----------+-------------------------------------------------------------------------+
      | 487818 | test_user | %:2065 | testdb | Query   |    0 | executing | SELECT * FROM information_schema.processlist WHERE Id = CONNECTION_ID() |
      +--------+-----------+--------+--------+---------+------+-----------+-------------------------------------------------------------------------+