For my own documentation, copied from here.
The following command which you will find everywhere out in the cloud is as follows:
sudo netstat -ltnp | grep ‘:80’ (it is important to note that apache was hanging and it did not matter what port I decided to investigate)
This would return the following:
tcp6 0 0 :::80 :::* LISTEN 1047/apache2
Then I ran the following command:
sudo kill -9 1047 (the pid that appears on your particular instance)
I was able to restart Apache and everything was groovy until I rebooted.