title: Apache can't create more than 400 workers
body: <p>I have a webserver that should handle about 800 simultaneous connections. 
  For this I have configured Apache 2.4 in worker mode (on Centos 6) with this values:</p>
  
  <p>
      ServerLimit                 40
      StartServers                25
      MaxClients                  1000
      MinSpareThreads             25
      MaxSpareThreads             75
      MaxRequestWorkers           1000
      ThreadsPerChild             25
      MaxConnectionsPerChild      0
  </p>
  
  <p>However, when I check the server-status I can not see more than 400 workers simultaneously.
  In error_log file I can see this: "[mpm_worker:error] [pid 2559:tid 140190319810368] AH00286: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting", but increasing this value has no effect. (with stop/start apache after each change in configuration file).
  I checked the ulimits and for apache user the value of nproc is 2048.
  I mention that Apache was compiled by me and I didn't set explicitly any limit at compilation time.</p>
  
  <p>What could be the cause of this limitation?</p>