If you happen to scan the web server log files of your dedicated server, as I have often recommend, you might come across a message saying something like, “[notice] Graceful restart requested, doing restart”. The first important thing to know about this message is the word “notice”. This means that it is not an error, but is simply letting you know that the restart occurred.
The second important thing to know is that a graceful restart is different from a regular restart or reloading of Apache HTTP Server. According to Apache documentation, the “graceful signal causes the parent process to advise the children to exit after current request”. In other words, as each child connected to an HTTP request ends its session, Apache will stop it and then replace it with a child running the new configuration settings. As such, Apache will not go down completely, and service to your websites should continue uninterrupted.
In order to initiate a graceful restart, type:
# apachectl -k graceful
But what if you did not tell Apache to restart but still see multiple restarts in the log? Chances are, you are running software, such as cPanel that automatically restarts Apache when configurations are changed. This might occur when a new site is created, an old one is deleted, or any number of other settings are changed.
If multiple graceful restarts occur so often that it causes problems on the server, you may have an actual problem that requires investigation. It may be a web script or other program that depends on Apache processes behaving badly. For more information about graceful restarts other ways to start and stop Apache, see the latest documentation.