Some experiences on MySQL Optimization on Linux host

Recently, the company's servers are always faulty. Sometimes the access speed is too slow to handle. I am just getting started with Linux, but I can't find the problem. I am so bored. First, I want to modify the mysql configuration file to check whether it is a database problem. cnf, which can only be learned after being instructed by others -(*). the cnf file is renamed to my. cnf login into/etc, to see their own database, the mysql-medium.cnf is renamed after login, in my. in cnf [mysqld], mysqldumpslow is added to record the slow mysql query statement. After running the statement for a few days, a record is not found and the record is lost. The permission and other statements have been changed, or not.

Later I thought about whether the problem was caused by max_connections. Running show variables in mysql found that max_connections only had 100, changed to 500, and then restarted mysql. It seems that there have been no problems in the past few days. I hope I have not found the cause of the error.