Multiple DHCP server processes

[markd]

> we have considered also such solution, but unfortunately it is not acceptable 
> - we need that changes take effect immediately (often the scenario is the 
> following - the person who makes onsite customer installations or 
> troubleshootings  calls our operator and asks him to change some parameters 
> for this customer which requires dhcpd restart and he can not wait for 
> scheduled intervals).

There are options in between "immediate" and every half hour.

We also have regular changes that require restart.  We queue them,
and a job runs every 5 minutes and only restarts if there's something
in the queue.  The field people have to wait on average a couple
minutes.  This keeps the thrashing way down, since in our setup
there are sometimes dozens of requests within a minute or two,
and other times, none for hours.

Mark