Q. Can I restart my Apache server on Linux?

Ans: Yes, you can restart your Apache server without affecting or killing other existing processes. For this, you should use the graceful restart command.

But this is possible, only if you have a VPS or a dedicated server hosting as you need to execute the commands through the root server

COMMAND:
service httpd graceful 

Graceful restart command will not kill any existing apache processes.

If you wish to kill the existing http processes and restart your apache server then use the following command:-

service httpd stop
service httpd startssl

Apache can also be restarted, along with any other service, from WHM. Simply log in, and select the service you wish to restart under the “restart services” section.