Need help with mysql configuration


I’ve xtradb cluster version 8.0 and i am using mysqltuner script to enhance the performance. Now i’ve the below message from mysqltuner…Can some one explain what to do?

General recommendations:
Run OPTIMIZE TABLE to defragment tables for better performance
Restrict Host for user@% to user@SpecificDNSorIp
Reduce your overall MySQL memory footprint for system stability
Adjust your join queries to always utilize indexes
Increase table_open_cache gradually to avoid file descriptor limits
Read this before increasing table_open_cache over 64:
Beware that open_files_limit (16364) variable
should be greater than table_open_cache ( 1024)
Variables to adjust:
*** MySQL’s maximum memory usage is dangerously high ***
*** Add RAM before increasing MySQL buffer variables ***
query_cache_size (>= 8M)
join_buffer_size (> 16.0M, or always use indexes with joins)
table_open_cache (> 1024)

Hello @elkhedewy,
Each one of those lines tells you what to do. There’s a lot there. OPTIMIZE TABLE will rebuild a table to remove empty free space; users with ‘%’ are considered a security risk; MySQL might be using too much memory so you’ll need to lower max_connections or reduce buffer pool size; optimize your queries (that’s a whole huge topic).
If you want more specific recommendations beyond what mysqltuner is telling you, I recommend you engage our support team. They can provide the specific commands/recommendations to you based on better evidence than this simple perl script.