Once mysqld starts, following message is logged int mysqld.err:
InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
This message means that mysqld fails to set thread priority, but not just because mysql user has no capability set in /etc/security/capability.conf (that is not relevant for the case at all), but because /usr/sbin/mysqld capabilities aren't set after installation.
Fixed by using setcap: setcap cap_ipc_lock,cap_sys_nice=ep /usr/sbin/mysqld
but every reinstall (recompilation) of mysqld binary resets this to default, so have to manually set after each mysqld rebuild.
Steps to Reproduce:
1. emerge dev-db/mariard
2. run getcap /usr/sbin/mysqld, this will print empty output (no capabilities)
3. start mysqld and check logs or check output of getpcaps $(pgrep mysql).
no mysqld capabilities set after reinstalling mariadb.
mysqld capabilities should be set by ebuild.
The bug has been closed via the following commit(s):
Author: Thomas Deutschmann <firstname.lastname@example.org>
AuthorDate: 2020-05-23 21:13:46 +0000
Commit: Thomas Deutschmann <email@example.com>
CommitDate: 2020-05-23 21:44:54 +0000
sys-cluster/galera: bump to v26.4.4
Package-Manager: Portage-2.3.99, Repoman-2.3.22
Signed-off-by: Thomas Deutschmann <firstname.lastname@example.org>
sys-cluster/galera/Manifest | 1 +
sys-cluster/galera/galera-26.4.4.ebuild | 81 +++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+)
Wrong bug linked.
No, setcap would be the wrong solution. See https://dev.mysql.com/doc/refman/8.0/en/innodb-parameters.html#sysvar_innodb_page_cleaners how to proper configure the system if you want to make use of this feature.