Hi list members, I have an issue with Apache's HTTP-Server 2.4. It says 'Resource temporarily unavailable: AH00159: fork: Unable to fork new process'. I know, there are some hits with Google, but there is no solution to me. Systemd knows about a task limit of 6000. mpm_prefork_module is set to 'ServerLimit 4000' and 'MaxRequestWorkers 4000'. ulimits are set to unlimited. I also see in the kernel log 'cgroup: fork rejected by pids controller in /system.slice/apache2.service'. But this does not correlate with the httpd's messages from above, that comes only from time to time. Why does this thing stop forking at about 3000 processes? I have a (not just one) Red Hat 6 in parallel, that one does.
Thanks, Martin.

