Why my server was stopped automatically

last -x | head | tac 

Output:

shutdown system down 4.14.62-65.117.a Mon Feb 28 06:00 - 08:25 (67+02:24) reboot system boot 4.14.62-65.117.a Fri May 6 08:25 - 09:08 (00:43) runlevel (to lvl 3) 4.14.62-65.117.a Fri May 6 08:25 - 09:08 (00:43) ec2-user pts/0 ip-68-79-10-91.u Fri May 6 08:35 still logged in 

When checking dmesg log, I found this:

/var/log/dmesg.old:389:[ 4.908827] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input3 /var/log/dmesg.old:390:[ 4.920486] ACPI: Power Button [PWRF] /var/log/cron:486:Feb 22 07:01:01 ip-68-79-20-2Feb 28 06:00:38 ip-68-79-20-21 crond[2845]: (CRON) INFO (Shutting down) /var/log/dmesg:386:[ 2.691395] input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input3 /var/log/dmesg:387:[ 2.698372] ACPI: Power Button [PWRF]