Why does my Netbeans Xdebug session timeout after period of inactivity

Find php.ini and add the following line to the xdebug section.

xdebug.remote_cookie_expire_time = 3600

The number is the time in seconds for the cookie to remain active, which defaults to 3600 (1 hour). I set it to 36000 (10 hours), which works fine and encourages me to restart the process occasionally to free memory. You can set it to 0 (unlimited) if you want, although I found that caused odd freezes here and there.

Remember to restart Apache for the change to kick in.

This is probably related to your Apache-Configuration.

The probable cause is a configured timeout that defines after what period of time the server ends the process if nothing happens ... makes sense usually, but when debugging you might be just busy taking a look at something.

My setup is somewhat different from yours but maybe I can help you.

In the apache-folder /sites-available are located the files that configure your domain-related virtual hosts. Within the -Tags of your Domain and protocol I put

<IfModule mod_fcgid.c>
     AddHandler fcgid-script .fcgi
     IdleTimeout 300
     IPCConnectTimeout 20
     IPCCommTimeout 120
     IdleScanInterval 120

That increased in my case the available period of time until the timeout would be triggered from 40 to 120 seconds.

Then (of course) restart your apache.

Maybe that helps.