[MDEV-30719] Documentation vor variable slave_run_triggers_for_rbr is not complete Created: 2023-02-23  Updated: 2023-03-24  Resolved: 2023-03-24

Status: Closed
Project: MariaDB Server
Component/s: Documentation, Replication
Fix Version/s: N/A

Type: Task Priority: Minor
Reporter: Oli Sennhauser Assignee: Ian Gilfillan
Resolution: Fixed Votes: 0
Labels: documentation, replication, slave

Issue Links:
Relates
relates to MDEV-5095 Executing triggers on slave in row-ba... Closed

 Description   

It is not visible from documentation if this variable slave_run_triggers_for_rbr is dynamic or not:

https://mariadb.com/kb/en/replication-and-binary-log-system-variables/#slave_run_triggers_for_rbr

Our experiment says: yes it is:

SQL> show global variables like 'slave_run%';
-----------------------------------+

Variable_name Value

-----------------------------------+

slave_run_triggers_for_rbr NO

-----------------------------------+
SQL> set global slave_run_triggers_for_rbr=LOGGING;
Query OK, 0 rows affected (0.000 sec)
SQL> show global variables like 'slave_run%';
-----------------------------------+

Variable_name Value

-----------------------------------+

slave_run_triggers_for_rbr LOGGING

-----------------------------------+
MDEV-5095 from Oleksandr points to the same direction
https://jira.mariadb.org/browse/MDEV-5095
If it really is changing in practice we will find out later in this PoC.

 Comments   
Comment by Oli Sennhauser [ 2023-02-23 ]

It seems not to be so easy or not consistent:

MariaDB [test]> SET GLOBAL slave_run_triggers_for_rbr = ON;
ERROR 1231 (42000): Variable 'slave_run_triggers_for_rbr' can't be set to the value of 'ON'

MariaDB [test]> SET GLOBAL slave_run_triggers_for_rbr = LOGGING;
Query OK, 0 rows affected (0.000 sec)

Comment by Oli Sennhauser [ 2023-02-23 ]

OK. My bad. Sorry! RTFM would help:

MariaDB [(none)]> SET GLOBAL slave_run_triggers_for_rbr = yes;
Query OK, 0 rows affected (0.000 sec)

Comment by Ian Gilfillan [ 2023-03-24 ]

Thanks, this has been added. It is also always possible to get this information from the Information Schema:

SELECT * FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES 
  WHERE VARIABLE_NAME LIKE 'slave_run%'\G
 
*************************** 1. row ***************************
 
        VARIABLE_NAME: SLAVE_RUN_TRIGGERS_FOR_RBR
 
...
 
            READ_ONLY: NO
 
...

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