28.3 Starting and Stopping Apache

If configured with YaST (see Section 28.2.2, Configuring Apache with YaST), Apache is started at boot time in runlevels 3 and 5 and stopped in runlevels 0, 1, 2, and 6. You can change this behavior using YaST's runlevel editor or the command line tool chkconfig.

To start, stop, or manipulate Apache on a running system, use the init script /usr/sbin/rcapache2 (refer to Section 14.2.2, Init Scripts for a general information about init scripts.). The rcapache2 command takes the following parameters:

status

Checks whether Apache is started.

start

Starts Apache if it is not already running.

startssl

Starts Apache with SSL support if it is not already running. For more information about SSL support, refer to Section 28.6, Setting Up a Secure Web Server with SSL.

stop

Stops Apache by terminating the parent process.

restart

Stops and then restarts Apache. Starts the Web server if it was not running before.

try-restart

Stops then restarts Apache only if it has been running before.

reload or graceful

Stops the Web server by advising all forked Apache processes to first finish their requests before shutting down. As each process dies, it is replaced by a newly started one, resulting in complete restart of Apache.

HINT: rcapache2 reload is the preferred method of restarting Apache in production environments, for example, to activate a change in the configuration, because it allows all clients to be served without causing connection break-offs.

restart-graceful

Starts a second Web server that immediately serves all incoming requests. The previous instance of the Web server continues to handle all existing requests for a defined period of time configured with GracefulShutdownTimeout.

rcapache2 restart-graceful is either useful when upgrading to a new version or when having changed configuration options that require a restart. Using this option ensures a minimum server downtime.

GracefulShutdownTimeout needs to be set, otherwise restart-graceful will result in a regular restart. If set to zero, the server will wait indefinitely until all remaining requests have been fully served.

A graceful restart can fail in case the original Apache instance is not able to clear all necessary ressources. In this case, the command will result in a graceful stop.

stop-graceful

Stops the Web server after a defined period of time configured with GracefulShutdownTimeout in order to ensure that existing requests can be finished.

GracefulShutdownTimeout needs to be set, otherwise stop-graceful will result in a regular restart. If set to zero, the server will wait indefinitely until all remaining requests have been fully served.

configtest or extreme-configtest

Checks the syntax of the configuration files without affecting a running Web server. Because this check is forced every time the server is started, reloaded, or restarted, it is usually not necessary to run the test explicitly (if a configuration error is found, the Web server is not started, reloaded, or restarted). The extreme-configtest options starts the Web server as user nobody and actually loads the configuration, so more errors can be detected. Note that although the configuration is loaded, it is not possible to test the SSL setup, because the SSL certificates cannot be read by nobody.

probe

Probes for the necessity of a reload (checks whether the configuration has changed) and suggests the required arguments for the rcapache2 command.

server-status and full-server-status

Dumps a short or full status screen, respectively. Requires either lynx or w3m installed as well as the module mod_status enabled. In addition to that, status must be added to APACHE_SERVER_FLAGS in the file /etc/sysconfig/apache2.