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MySQL Replication and Read Replica Configuration

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Enable and Test Read Replica Lag

1. Configure Slow Query Logging:
   SET GLOBAL slow_query_log = 1;
   SET GLOBAL slow_query_log_file = '/path/to/slow_query.log';
   SET GLOBAL long_query_time = 1;
   
2. Create a Lag:
   SELECT SLEEP(2); -- This query will sleep for 2 seconds
   

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Test Logging

1. Enable General and Slow Query Logging:
   SET GLOBAL general_log = 1;
   SET GLOBAL slow_query_log = 1;
   SET GLOBAL long_query_time = 2;
   SET GLOBAL log_output = 'FILE';
   
2. Modify Parameter Group:
   • You cannot modify the parameter settings of a default DB parameter group. Instead, create and modify a custom DB parameter group if the parameter is modifiable.
   Steps to modify the DB parameter group:
   1. Open the Amazon RDS console.
   2. Choose Databases from the navigation pane.
   3. Select the instance you want to associate with the DB parameter group.
   4. Choose Modify.
   5. From the Database options section, select the DB parameter group you want to associate with the DB instance.

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Manage Replication Delay

1. Stop Replication:
   CALL mysql.rds_stop_replication;
   
2. Set Replication Delay:
   CALL mysql.rds_set_source_delay(120); -- Set delay to 120 seconds
   
3. Start Replication:
   CALL mysql.rds_start_replication;
   

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Show Logs

1. General Log:
   SELECT * FROM mysql.general_log;
   
2. Slow Query Log:
   SELECT * FROM mysql.slow_log;
   

Feel free to adjust the paths, parameters, or steps based on your specific requirements or environment!