Gentle shutdown feature

[Shawn Routhier]

In the 4.3.0 release cycle we added a feature to gently shutdown
clients and servers when they received SIGINT and SIGTERM
signals.  This feature was included in the changes back ported to 
4.1-ESV and 4.2 and has two side effects that may affect users.
This was done to allow any writes to the lease files to complete
before the process stops.

When a client receives a SIGINT or SIGTERM signal  the new
behavior is to send a release message to the server.

When a server receives a SIGINT or SIGTERM signal "if" failover 
is in use then when the server is restarted it may go through recover
wait for a number of seconds (determined by the server's MCLT
setting)  before becoming usable.


In both of these cases the previous functionality can be gotten
by halting the process with a different signal, for example
"kill -9 <pid>"

We have received a report objecting to this feature
and we are determining the best course of action.

1) Are you already making use of this feature?  Or would it
not be an issue if we disabled it?

2) Has this feature caused issues for you?

3) Any other useful comments about this issue?

Shawn Routhier
ISC DHCP