When I installed Percona XtraDB Cluster 5.7 on CentOS 7.6, I noticed that the /var/log/mysqld.log file has -rwxr-xr-x DAC rights with a mysqld_log_t type owned by mysql:mysql. This seemed excessive (both because I can’t think of a reason to have execute rights on a log file and because it’s almost unheard of for a log file to be world readable) so I installed 5.7 community from the Oracle repo to compare. In that version the label and ownership are the same, but the DAC is -rw-r----- which seems more appropriate for a log file to me.
Does anyone know why the log file in Percona’s fork would be executable or DAC world readable? If it’s necessary, I can rely on other compensating controls, but if it’s not my defense in depth instincts would like to set those rights to match the Oracle version. In the absence of a reason, has anyone had any issues making this change (i.e. the rights are actually necessary) or is it one of those things that got set that way during a troubleshoot and never got set back? If I had a nickel for every one of those…