systemd: Ignore exit code of [email protected] instantiations

[TwizzyDizzy]

Recently, the support for systemd based status checking has been implemented.

Due to the way MariaDB Community Edition implements the locking during a mariabackup in comparison to MariaDB Enterprise Edition, it is possible, that during a mariabackup some instantiations of [email protected] will fail because the check for wsrep_ready briefly reports OFF.

This leads to the units failing and impeding the overall system state as seen by systemctl status:

● HOSTNAME
    State: degraded
    Units: 331 loaded (incl. loaded aliases)
     Jobs: 0 queued
   Failed: 1 units
    Since: Thu 2024-08-15 16:25:35 CEST; 4 weeks 1 day ago
  systemd: 252-32.el9_4.6
  Tainted: local-hwclock
   CGroup: /

and

root@HOSTNAME / # systemctl --failed
  UNIT                                                            LOAD   ACTIVE SUB    DESCRIPTION                            
● [email protected]:9220-192.168.0.0:34154.service loaded failed failed mysqlchk service (192.168.0.0:34154)

We therefore propose to not honor the exit code of the instantiations of [email protected].

Cheers Thomas

[fraenki]

Merged, thanks!