Hi, the epoll limit in new linux kernels can cause problems because of insufficient error checking in httpd. The most obvious problem was fixed in https://issues.apache.org/bugzilla/show_bug.cgi?id=46467 in MPM prefork, but mod_cgi, mod_proxy_connect, and the other MPMs should also check for errors in apr_pollset_create/add.
Patch is at https://issues.apache.org/bugzilla/attachment.cgi?id=23105 For the documentation: This means that the limit in /proc/sys/fs/epoll/max_user_instances needs to be twice the number of MaxClients to handle the worst case of every process doing a proxy CONNECT or cgi request. Cheers, Stefan
