Today I moved one of my wordpress powered site to a VPS. But when online users reached about 50, the pages began to load very slow and then at last the pages wouldn't load. All I get now is a HTTP 500 error there. Anyone knows what causes the problem? What should I do now? I'm so sad. It's a unmanaged VPS, 540MB RAM, running Apache and MySQL.
Here's the error.log: WordPress database error MySQL server has gone away for query... Code (markup):
I contact the support. Thay answered my ticket: Have you tuned the Apache MaxClients directive to limit the number of connections Apache will service at once? If Apache is trying to launch too many processes, your VPS will start using swap to stay up and performance will drop off. Code (markup): I still dont know what to do next.
Check the .htaccess file. Usually this is something like modrewrite or another function that isn't supported.