I have installed mysql 5.5.58 on centos 6.9 in which I plan to mount cacti to monitor my network, I have installed php 5.4.45 and apache 2.4 the problem is that when starting the cacti installation process, the wizard tells me that I must make some modifications in the file my.cnf that is inside /etc/my.cnf, the problem is that I make the mentioned changes but mysql apparently does not seem to take them into account since the cacti installer keeps showing me that the changes have not been carried out, look why this happened and apparently mysql ignores the changes made to the files that have writable permissions in some way I realized that the permissions were modified and had 777 permissions and recommended modifying them to 644, perform this modification but mysql still does not take into account the new configurations. my my.cnf file is as follows.
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
symbolic-links=0
#Semisynchronous Replication
#http://dev.mysql.com/doc/refman/5.5/en/replication-semisync.html
#uncomment next line on MASTER
;plugin-load=rpl_semi_sync_master=semisync_master.so
#uncomment next line on SLAVE
;plugin-load=rpl_semi_sync_slave=semisync_slave.so
#Other options for Semisynchronous Replication
;rpl_semi_sync_master_enable=1
;rpl_semi_sync_master_timeout=10
;rpl_semi_sync_slave_enable=1
#http://dev.mysql.com/doc/refman/5.5/en/performance/-schema.html
;performance_schema
[mysqld safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
#Cacti configurations
max_heap_table_size = 100M
max_allowed_packet = 16M
tmp_table_size = 64M
innobd_file_per_table = ON
innobd_buffer_pool_size = 450M
innobd_doublewrite = OFF
innobd_additional_mem_pool_size = 80M
#include all files rom the config directory
!include etc/my.cnf.d