dhcpd stops issuing leases with sporadic "no available billing: lease limit reached in all matching classes"

[Glenn Satchell]

Hi Richard

Can you post your dhcpd.conf and messages from the logs?

regards,
-glenn

On 05/07/10 16:07, Richard Laager wrote:
> Every day or so, our dhcpd starts logging "no available billing: lease
> limit reached in all matching classes". It'll do this for varying
> lengths of time... I believe we've seen 30 minutes to 6 hours. Customers
> on certain networks will effectively see DHCP as "down" (i.e. they don't
> get leases). Other networks served by the same instance of dhcpd,
> however, get leases fine during this time.
>
> When this first started happening, we didn't catch it right away and it
> would sometimes start working again on its own. When we did catch it,
> we'd restart dhcpd and it'll immediately work again. Now, we have a
> watchdog script running from cron every minute to tail the logs and
> restart dhcpd (when this error message shows up) to workaround this
> issue.
>
> We were running fine for several years on a system with Ubuntu "Dapper"
> 6.06 and what we believe was dhcpd 3.0.6 rebuilt from the dhcpd package
> from Ubuntu "Hardy" 8.04. Why were we using a backport instead of the
> dhcpd 3.0.3 that shipped with Dapper? We were having some sort of issue.
> We think it may be the same as the issue we were having now, but it's
> been at least a couple of years and nobody remembers for sure.
>
> The old DHCP server suffered the "loss" of both hard drives
> simultaneously. (They started returning lots of read errors and/or bad
> data so the RAID card dropped one and the filesystem went read-only.) We
> replaced the drives and installed Ubuntu "Lucid" 10.04, which shipped
> with dhcpd 3.1.3. We were able to grab the conf and leases files from
> the old server before replacing the drives. The new install appeared to
> work fine, until a day or so later when this error started showing up.
>
> We tried rebuilding the 3.0.6 package from Hardy, but that did not
> resolve the issue. Then, we rebuilt the 4.1.1 package from Debian
> experimental. That has the same issue.
>
> I believe that 3.0.6 was using a more generic error (perhaps just "no
> available billing"), so our watchdog script wouldn't trigger properly.
> And we can't change the script to check for "no available billing", as
> that seems to occur normally (when someone tries to get a lease when
> they already have as many as they're allowed?).
>
> I believe this is a bug as the behavior varies across a restart of
> dhcpd. However, I can't be sure what is going on.
>
> What should I do next?
>
> Thanks,
> Richard
>