MySQL 4G memory server configuration optimization

[mysqld] 
 port = 3306 
 serverid = 1 
 socket = /tmp/mysql.sock 
 skip-locking 
#Avoid external locking of MySQL, reduce the chance of errors and enhance stability. 
skip-name-resolve 
#Disable MySQL from performing DNS resolution on external connections. Using this option can eliminate the time it takes for MySQL to perform DNS resolution. But please note that if this option is turned on, all remote host connection authorizations must use the IP address method, otherwise MySQL will not be able to process the connection request normally!
back_log = 384 
The value of the #back_log parameter indicates how many requests can be stored in the stack in a short period of time before MySQL temporarily stops responding to new requests. If the system has many connections in a short period of time, you need to increase the value of this parameter, which specifies the size of the listening queue for incoming TCP/IP connections. Different operating systems have their own limitations on this queue size. Attempting to set back_log higher than your operating system's limit will have no effect. The default value is 50. For Linux systems, it is recommended to set this parameter to an integer less than 512.
key_buffer_size = 256M 
#key_buffer_size specifies the buffer size used for indexing. Increasing it can get better index processing performance. For servers with around 4GB of memory, this parameter can be set to 256M or 384M. Note: If this parameter value is set too high, the overall efficiency of the server will be reduced!
max_allowed_packet = 4M 
 thread_stack = 256K 
 table_cache = 128K 
 sort_buffer_size = 6M 
#Query the buffer size that can be used when sorting. Note: The allocated memory corresponding to this parameter is exclusive to each connection. If there are 100 connections, the total sort buffer size actually allocated is 100 × 6 = 600MB. Therefore, for servers with around 4GB of memory, the recommended setting is 6-8M.
read_buffer_size = 4M 
#The buffer size that can be used for read query operations. Like sort_buffer_size, the allocated memory corresponding to this parameter is also exclusive to each connection.
join_buffer_size = 8M 
#The buffer size that can be used for joint query operations. Like sort_buffer_size, the allocated memory corresponding to this parameter is also exclusive to each connection.
myisam_sort_buffer_size = 64M 
 table_cache = 512 
 thread_cache_size = 64 
 query_cache_size = 64M 
#Specify the size of the MySQL query buffer. You can observe in the MySQL console that if the value of Qcache_lowmem_prunes is very large, it indicates that the buffer is often insufficient; if the value of Qcache_hits is very large, it indicates that the query buffer is used very frequently. If the value is small, it will affect the efficiency. In this case, you can consider not using the query buffer; Qcache_free_blocks, if the value is very large, it indicates that there are a lot of fragments in the buffer.
tmp_table_size = 256M 
 max_connections = 768 
#Specify the maximum number of connection processes allowed by MySQL. If the error message "Too Many Connections" often appears when accessing the forum, you need to increase the value of this parameter.
max_connect_errors = 10000000 
 wait_timeout = 10 
#Specify the maximum connection time for a request. For a server with about 4GB of memory, it can be set to 5-10. 
thread_concurrency = 8 
#The value of this parameter is the number of logical CPUs on the server*2. In this example, the server has 2 physical CPUs, and each physical CPU supports HT hyperthreading, so the actual value is 4*2=8
 skip-networking 
#Enabling this option can completely shut down the TCP/IP connection mode of MySQL. If the WEB server accesses the MySQL database server via a remote connection, do not enable this option! Otherwise the connection will not work!
table_cache=1024 
#The larger the physical memory, the larger the setting. The default is 2402, and the best setting is 512-1024 innodb_additional_mem_pool_size=4M 
#Default is 2M 
 innodb_flush_log_at_trx_commit=1 
#Set to 0 to wait until the innodb_log_buffer_size queue is full before storing them all together. The default value is 1 
 innodb_log_buffer_size=2M 
#Default is 1M 
 innodb_thread_concurrency=8 
#Set it to the number of CPUs on your server. The default value is usually 8. 
 key_buffer_size=256M 
#The default is 218, adjust to 128 for the best tmp_table_size=64M 
#The default is 16M, adjust to 64-256 for the best read_buffer_size=4M 
#Default is 64K 
 read_rnd_buffer_size=16M 
#Default is 256K 
 sort_buffer_size=32M 
#Default is 256K 
 thread_cache_size=120 
#Default is 60 
 query_cache_size=32M