Apache Global Configuration Apache MPM (multi-processing modul) Common Directives

Apache Architecture

StartServers - No of Child Server Process created when starting Apache. - As the number of processes is dynamically controlled depending on the load, there is usually little reason to adjust this parameter.

Minimum Spare Servers -Minimum no of Child Server Process will remain exist even Apache got nothing to do (idle) -Tuning of this parameter should only be necessary on very busy sites

Maximum Spare Servers -Maximum no of Child Server Process will remain exist even Apache got nothing to do (idle) -Tuning of this parameter should only be necessary on very busy sites

Max Clients -The MaxClients directive sets the limit on the number of simultaneous requests that will be served -Any connection attempts over the MaxClients limit will normally be queued -Once a child process is freed at the end of a different request, the connection will then be serviced.

ServerLimit -This directive sets the maximum configured value for MaxClients for the lifetime of the Apache process. -If ServerLimit is set to a value much higher than necessary, extra, unused shared memory will be allocated -Highly recommend using the default setting unless you fully understand how it will interact with your Apache build and MaxClients setting.

MaxRequestsPerChild -The MaxRequestsPerChild directive sets the limit on the number of requests that an individual child server process will handle. -After MaxRequestsPerChild requests, the child process will die. - If MaxRequestsPerChild is 0, then the process will never expire.

Keep-Alive Timeout -The number of seconds Apache will wait for a subsequent request before closing the connection. -Once a request has been received, the timeout value specified by the Timeout directive applies.

Max Keep-Alive Requests -The MaxKeepAliveRequests directive limits the number of requests allowed per connection when KeepAlive is on. -If it is set to 0, unlimited requests will be allowed. -Its recommend that this setting be kept to a high value for maximum server performance.

Timeout -Amount of time the server will wait for certain events before failing a request -Example: -In mod_cgi, the length of time to wait for output from a CGI script -When reading data from the client, the length of time to wait for a TCP packet to arrive if the read buffer is empty