Does Maxscale 6.1.3 prevent the reassembly of user variables?

Hello

We see a slight difference between version 10.3.27-MariaDB-0 + deb10u1-log and version 10.5.12-MariaDB-1: 10.5.12 + maria ~ buster-log.
Unless it is from the maxscale layer.

– Reproduce with

CREATE DEFINER=`cluster`@`%` PROCEDURE `test_proc`(IN myinparam INT, OUT myoutparam INT)

    SQL SECURITY INVOKER

BEGIN

  SELECT myinparam;

  Set myoutparam = myinparam * 2;

  -- SELECT myinparam * 2 INTO myoutparam; -- same behavior

  SELECT myinparam, myoutparam;

END

– Test script

SET @myvar = 10;

SELECT 'before', @myvar;

CALL melolo_test.test_proc(123, @myvar);

SELECT 'after', @myvar;

– case tested
>>> MariaDB 10.3 solo
1.1- host local(user 'cluster') with PROC DEFINER (cluster@%) <=> mariadb (10.3.27) => OK
> before 10
> after 256

1.2- host local(user 'cluster') with PROC DEFINER (admin@%) <=> mariadb (10.3.27) => OK
> before 10
> after 256

>>>> MariaDB 10.5 by Mascale 6.1.3
2.1- host local(user 'cluster') with PROC DEFINER (cluster@%) <=> maxscale 6.1.3 <=> cluster (10.5.12) => KO
> before 10
> after 10

2.2- host local(user 'cluster') with PROC DEFINER (admin@%) <=> maxscale 6.1.3 <=> cluster (10.5.12) => KO
> before 10
> after 10

2.3- host local(user 'admin') with PROC DEFINER (cluster@%) <=> maxscale 6.1.3 <=> cluster (10.5.12) => KO
> before 10
> after 10

2.4- host local(user 'admin') with PROC DEFINER (admin@%) <=> maxscale 6.1.3 <=> cluster (10.5.12) => KO
> before 10
> after 10

>>>> MariaDB 10.5 directement node master
3.1- host local(user 'cluster') with PROC DEFINER (cluster@%) <=> node master (10.5.12) => OK
> before 10
> after 256

3.2- host local(user 'cluster') with PROC DEFINER (admin@%) <=> node master (10.5.12) => OK
> before 10
> after 256

3.3- host local(user 'admin') with PROC DEFINER (cluster@%) <=> node master (10.5.12) => OK
> before 10
> after 256

3.4- host local(user 'admin') with PROC DEFINER (admin@%) <=> node master (10.5.12) => OK
> before 10
> after 256

Regardless of the user <=> definer couple:

• the script does not return the correct result by Maxscale
• the script returns the correct result without passing Maxscale

Would Maxscale block user variables?
To do this, I completed the tests by repeating the script below on directly on the master node and via maxscale

1) First pass
>>>> MariaDB 10.5 directement sur le node master avec le user admin

SELECT '@myvar_from_nodeMaster', @myvar_from_node7, '@myvar_from_maxscale', @myvar_from_maxscale;

> '@myvar_from_nodeMaster', null, '@myvar_from_maxscale', null;

SET @myvar_from_nodeMaster = 654321;

SELECT '@myvar_from_nodeMaster', @myvar_from_nodeMaster, '@myvar_from_maxscale', 

@myvar_from_maxscale;

>'@myvar_from_nodeMaster', 654321, '@myvar_from_maxscale', null;

>>>> MariaDB 10.5 by Mascale 6.1.3 avec le user admin

SELECT '@myvar_from_node7', @myvar_from_node7, '@myvar_from_maxscale', @myvar_from_maxscale;

> @myvar_from_node7, null, @myvar_from_maxscale, null

set @myvar_from_maxscale = 123456;

SELECT '@myvar_from_node7', @myvar_from_node7, '@myvar_from_maxscale', @myvar_from_maxscale;

> @myvar_from_node7, null, @myvar_from_maxscale, 123456

2) Second pass
>>>> MariaDB 10.5 directement node master avec le user admin

SELECT '@myvar_from_nodeMaster', @myvar_from_nodeMaster, '@myvar_from_maxscale', @myvar_from_maxscale;

>'@myvar_from_nodeMaster', 654321, '@myvar_from_maxscale', null;
>>>> MariaDB 10.5 by Mascale 6.1.3 avec le user admin

SELECT '@myvar_from_nodeMaster', @myvar_from_nodeMaster, '@myvar_from_maxscale', @myvar_from_maxscale;

> @myvar_from_node7, null, @myvar_from_maxscale, 123456

Although we always connect with the same user, the variables remain watertight between the 2 connection spaces ...

Is there a way around this?

Thank you in advance for your return