mysql has two pid files I just finished re-building my (5.7) slave from a hot backup. When I issue
 systemctl start mysqld

it just &quot;sat&quot; there for over 20 minutes. It usually takes less than 10 seconds for the service to start. When I look at my server status, I see two mysql processes
mysql     1938     1  0 15:25 ?        00:00:00 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
mysql     1940     1 99 15:25 ?        00:11:48 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
root      4024  3122  0 15:37 pts/0    00:00:00 grep --color=auto mysqld

I stopped and restarted my service and there are two different PIDs showing up again
 [root@bi-db002-prd ~]# systemctl status mysqld -l
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: activating (start) since Mon 2020-08-17 15:46:45 UTC; 45s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 7066 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
  Control: 7088 (mysqld)
   CGroup: /system.slice/mysqld.service
           ├─7088 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
           └─7092 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

Aug 17 15:46:45 bi-db002-prd systemd[1]: Starting MySQL Server...

I have never seen that. Is there something incorrect with my configuration?
yes this is normal, mysql can so handle multiple requests, like apache webserver or firfox which do the same.
actually 2 is quite low, , if the number of requests/connections increases so will the number of proce4sses(till max Connections is reached). Two means that you and a free process are at the moment  connected