Failover on a large DHCP system
Nicholas F Miller
Nicholas.Miller at Colorado.EDU
Fri May 8 17:00:33 UTC 2009
> On Fri, May 08, 2009 at 10:09:29AM -0600, Nicholas F Miller wrote:
> > With constant restarts of DHCP and the need for
> > failover to redistribute the pools on restarts I think the server
> load and
> > disk access would be too high.
> The disk access footprint between failover restarts is only the
> "changes" to the database. It doesn't remirror the lease db every
> reconnect - they only update each other with any new bindings that
> ocurred during the blackout.
> With huge numbers of leases, it can be a problem however, as it causes
> both servers to traverse the entire lease database (in memory) right
With around 72,000 leases at any given time and 677 pools, should we
just continue using our current restart methodology or try to
implement omshell as a way to add/remove the hosts? Since omshell
writes its changes to the leases file, the changes will survive a
restart, ignoring the config. This could lead to some interesting
troubleshooting if something were to go awry.
Nicholas Miller, ITS, University of Colorado at Boulder
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