502 Bad Gateway nginx with high traffic server

[isomonkpiss]

Hello Guys,

i have a dedicated server with plesk 12,5

64 ram

using php 5.5.9 with fastcgi and wordpress application.

my Problem is that when i have over 400 People same Time then i have an error with 502 Bad Gateway nginx.

i checked all the plesk docs about this issue but no solution.

i thng realy that Plesk is not for high Traffic Server build.

What can i do to Increase Performance and allow high Traffic with no nignx errors?

I have all configs to default. opcache maybe the Problem?

 

[JürgenT]

More Output !

Look in /var/log/* particularly nginx error log

 

[isomonkpiss]

there are no erros abour nginx

i have plesk with one site on dedicated.. my question is how can i increase Plesk to use all the resources for this ONE Site.

what can i do?

any config tip?

thank you

 

[IgorG]

Any related errors from nginx log files at least? Do you have the same problem with another php handler or php version?