rsyslog fails to start on boot with "Start request repeated too quickly" error

Issue

• The rsyslog service fails to start automatically during system boot or after a logrotate event, even though it can be started manually without issue.

  • The systemctl status rsyslog command shows Active: failed (Result: procotol), (code=killed, signal=HUP) as exit reason and an error message: Start request repeated too quickly.

    × rsyslog.service - System Logging Service
         Loaded: loaded (/usr/lib/systemd/system/rsyslog.service; enabled; preset: enabled)
         Active: failed (Result: protocol) since Tue 2025-08-26 10:19:33 JST; 1min 14s ago
           Docs: man:rsyslogd(8)
                 https://www.rsyslog.com/doc/
        Process: 2068 ExecStart=/usr/sbin/rsyslogd -n $SYSLOGD_OPTIONS (code=killed, signal=HUP)   <<===
       Main PID: 2068 (code=killed, signal=HUP)
            CPU: 804us
    
     8月 26 10:19:33 myrhel9 systemd[1]: rsyslog.service: Scheduled restart job, restart counter is at 5.
     8月 26 10:19:33 myrhel9 systemd[1]: Stopped System Logging Service.
     8月 26 10:19:33 myrhel9 systemd[1]: rsyslog.service: Start request repeated too quickly.   <<===
     8月 26 10:19:33 myrhel9 systemd[1]: rsyslog.service: Failed with result 'protocol'.
     8月 26 10:19:33 myrhel9 systemd[1]: Failed to start System Logging Service.