The current ganglia reporter doesn't set metric expiration time (dmax). The metrics of all finished applications are indefinitely left displayed in ganglia web. The dmax parameter allows user to set the lifetime of the metrics. The default value is 0 for compatibility with previous versions.

Author: Ekasit Kijsipongse <ekasitk@gmail.com>

Closes #11127 from ekasitk/ganglia-dmax.