[ale] Linux-HA to convert a slave to a master

[Jim Lynch]

Jim Kinney wrote:
> Yep. Ping is not a reliable test. Better to actually use the slave to 
> probe the master for the same functionality the master is supposed to 
> be serving. Likewise setup a watchdog process on the master to look at 
> the slave for a confirmation file. If it's present, all is ok. If it's 
> missing, restart the process and flag a counter. Wait an appropriate 
> restart time and retest the slave for confirmation. If it still 
> missing, signal the slave for imminent shutdown and call a halt.
To make it work without conflicts, have the slave power the offending 
master off.

Jim.