httpd service restart error:(98)Address already in use: AH00072: make_sock: could not bind t o address 0.0.0.0:80

Recently, on one of the ec2 instance, there was a httpd restart problem, where the below error was thrown

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$ sudo service httpd restart
Stopping httpd:                                            [FAILED]
Starting httpd: (98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
AH00015: Unable to open logs
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After checking for folder/file level permissions, I followed the suggestions made in one blog post. However, that did not help and I could not kill the httpd process. Later, I suspected that httpd.pid file was not writable. Turned out that that file did not exist (that is another investigation altogether). I created two files in <apache_home>/logs folder

$touch httpd
$vi httpd.pid
<pid>

Once I had done that then I was able to stop and start httpd process again.