Someone asked you how much the number of concurrent websites? It can withstand the number of concurrent How much? How to answer it?
To your load balancing server to see it!
ss antigen | grep -i est | wc -l
Then the number of concurrent websites can afford is how much? Need to use tools to measure, operation and maintenance personnel with ab, webbench, etc., there is a little more professional loadrunner. Here the record about ab usage: