DHCP Performance (was: Large leases file and long startup time)

[Jason Antman]

We're starting to get into some more depth troubleshooting DHCP
performance issues - not just startup, but running as well. Our DHCP
server (yes, singular) supports a network with approx. 15,000 users, all
DHCP'ed. During peak times (usually once or twice a day), we see upwards
of 2-3k requests in a 15-30 minute interval.

We've been running DHCPerf
(http://www.nominum.com/services/measurement_tools.php) against a
testing box, and we're seeing pretty poor performance - something on the
order of only 1 request per second being handled within a 4 second window.

Does anyone else out there have an idea of the load that their dhcpd
instance is handling? Has anyone else with sustained loads around 1-3
RPS had issues? Is anyone else running something on the order of 400+
subnets and 10000+ clients?

Thanks,
Jason Antman

Rutgers University

Jason Antman wrote:
> Hello,
>
> We're running DHCPd (currently 3.0.5) to serve a bunch of networks that
> are mostly static, some dynamic. At the moment, it's 431 subnets, 1762
> clients. We're currently using 3.0.5 with Masney's LDAP patch, but have
> been having some serious startup time issues - on the order of 5
> minutes. I did some investigation with static configs (compiled exactly
> from what's in LDAP) and the time is more or less the same. It appears
> that the bottleneck is reading the leases file, which is on the order of
> 2.3M on our production boxes (with only about 10% max of our clients
> active).
>
> Has anyone else found similar issues? Is there any conceivable solution
> - reading the leases file from a database, or storing it in something
> more optimized than a text file?
>
> Thanks for any advice,
> Jason Antman
>
>