Trigger on slave only - mysql

Question

I am trying to run a trigger on slave for RBR (https://mariadb.com/kb/en/library/running-triggers-on-the-slave-for-row-based-events/).
I have created a table on master like this:
CREATE TABLE `t1` (
`id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`mobile` varchar(20) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
On slave, I had this trigger:
CREATE TRIGGER t1_obfus AFTER INSERT ON `t1`
FOR EACH ROW
UPDATE `t1`
SET `mobile` = LEFT(MD5(NEW.`mobile`), 20);
which did not work. I got the following error on SHOW SLAVE STATUS:
Last_SQL_Error: Could not execute Write_rows_v1 event on table d1.t1; Can't update table 't1' in stored function/trigger because it is already used by statement which invoked this stored function/trigger., Error_code: 1442; handler error HA_ERR_GENERIC; the event's master log mariadb-bin.000004, end_log_pos 454
Then I modified the trigger to:
CREATE TRIGGER t1_obfus BEFORE INSERT ON `t1`
FOR EACH ROW
UPDATE `t1`
SET NEW.`mobile` = LEFT(MD5(NEW.`mobile`), 20)
WHERE id = NEW.id;
but it still did not work. Then I created a new table on slave:
CREATE TABLE t1_2 (
id BIGINT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
mobile VARCHAR(20)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
and modified my trigger to:
CREATE TRIGGER t1_obfus BEFORE INSERT ON `t1_2`
FOR EACH ROW
INSERT INTO `t1_2` (id, mobile)
VALUES (NEW.id,LEFT(MD5(NEW.`mobile`), 20));
Now the replication started working but there is no data in the table t1_2. How do I fix this?

Answer 1

If you use row-based replication, triggers on the slave won't work.
As described in the official documentation:
Blockquote
If you want triggers to execute on both the master and the slave—perhaps because you have different triggers on the master and slave—you must use statement-based replication. However, to enable slave-side triggers, it is not necessary to use statement-based replication exclusively. It is sufficient to switch to statement-based replication only for those statements where you want this effect, and to use row-based replication the rest of the time.