After install Percona Server 5.7 via yum repos, the cnf files look like:
[root@marcos-albe-centos7-001 ~]# tail -n +1 /etc/percona-server.conf.d/*
==> /etc/percona-server.conf.d/mysqld.cnf <==
# Percona Server template configuration
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
# Disabling symbolic-links is recommended to prevent assorted security risks
==> /etc/percona-server.conf.d/mysqld_safe.cnf <==
# The Percona Server 5.7 configuration file.
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
# For explanations see
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
nice = 0
Notice how socket paths differ (/var/lib/mysql/mysql.sock vs /var/run/mysqld/mysqld.sock).
In a systemd linux it took the one under [mysqld]
[root@marcos-albe-centos7-001 ~]# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.29-32 Percona Server (GPL), Release 32, Revision 56bce88
Copyright (c) 2009-2020 Percona LLC and/or its affiliates
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> select @@socket;
| @@socket |
| /var/lib/mysql/mysql.sock |
1 row in set (0.00 sec)