Since yesterday, my WP (3.3.2) site often displays 500 and 503 errors. On the server error log, I've found two entries which happens often, and I believe these are the cause of the errors.
[warn] (103)Software caused connection abort: mod_fcgid: ap_pass_brigade failed in handle_request function
[warn] mod_fcgid: can't apply process slot for /var/www/vhosts/example.com/httpdocs/index.php
I didn't make any large changes to my site including plugins and themes, so I've been wondering if it's a problem of WordPress side or the server side. It would be great if anyone points me to right direction to solve it.