Services such as Apache (web server) can need restarting from time to time. Most of these services can be managed via the Plesk control panel.
Step 1-From your Plesk control panel select Tools & Settings from the Server Management section.
Step 2-Select Services Management from the Server Management section.
Step 3-You will see a list of the services you can manage. You can use the icons to the right of these to start, stop or restart the service.