There is a company website with more than 6,000 IP visits per month. The server configuration has been changed to a 4G memory centos server. Apache 2.4 is used as the website server. The website uses pseudo-static access through the proxy server reverse proxy. It has just been online for about 5 minutes. , apache quickly fills up the memory, making the server inaccessible. However, the mysql server configured with the same configuration is normal and only takes up less than 1G of memory. What optimizations need to be done on apache in this situation? Or what monitoring methods are there?