Adding max_connections to mysql configuration file my.cnf does not take effect

1. my.cnf is set to max_connections = 2000, but the maximum number of connections is 214

2. Solution:
Add LimitNOFILE=65535 to the [Service] section in the mysql service file mysqld.service
vi /lib/systemd/system/mysqld.service

3. Restart the service and check

The maximum number of database connections
show variables like '%max_connections%';

The maximum number of connections used
show global status like 'Max_used_connections';

The thread status used
show status like 'Threads%';

4. Display the threads that the user is running
show processlist;

5. Database performance status
1) QPS amount
Com_select: The total number of query statements executed by MySQL from the last time it was started to the current
show global status where variable_name='Com_select';

2) TPS amount
Com_commit: The total number of commit statements executed by MySQL from the last time it was started to the current
show global status where variable_name='Com_commit';