Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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2.5
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None
Description
The documentation for the causal_reads parameter for readwritesplit has the following note:
Note: This feature requires MariaDB 10.2.16 or newer to function. In addition to this, the session_track_system_variables parameter must be set to last_gtid.
https://mariadb.com/kb/en/mariadb-maxscale-25-readwritesplit/#causal_reads
This seems to imply that you should do something like this:
SET GLOBAL session_track_system_variables='last_gtid'; |
and:
[mariadb]
|
session_track_system_variables=last_gtid
|
However, in 10.3 and later, this system variable has a non-empty default value that some users may want to keep: autocommit,character_set_client,character_set_connection,character_set_results,time_zone.
Therefore, it may be more appropriate for users to set it like this:
SET GLOBAL session_track_system_variables=CONCAT(@@global.session_track_system_variables, ',last_gtid'); |
and:
[mariadb]
|
session_track_system_variables=autocommit,character_set_client,character_set_connection,character_set_results,time_zone,last_gtid
|
Maybe it would be more appropriate for the documentation to say something like this?:
Note: This feature requires MariaDB 10.2.16 or newer to function. In addition to this, the session_track_system_variables parameter must include last_gtid in its list of tracked system variables.