high performance open source DHCP solution?

Florian Weimer fweimer at bfk.de
Mon Jul 25 10:59:44 UTC 2011


* Jimmy Hess:

> On Wed, Jul 20, 2011 at 9:31 AM, Nick Colton <ncolton at allophone.net> wrote:
>> We were seeing similar issues with low leases, moved the dhcpd.leases file
>> to a ramdisk and went from ~200 leases per second to something like 8,000
>> leases per second.
>
> Yes, blame RFC2131's requirement that a DHCP server is to ensure that
> any lease is committed to persistent storage, strictly before a DHCP
> server is allowed to send the response to the request; a fully
> compliant DHCP server with sufficient traffic is bound by the disk I/O
> rate of underlying storage backing its database.

Come on, group commits are not that difficult to implement.  With them,
you should be able to obtain 8 kHZ leases on a single spindle (assuming
the per-client data is just a few hundred bytes), without violating the
RFC requirement.

-- 
Florian Weimer                <fweimer at bfk.de>
BFK edv-consulting GmbH       http://www.bfk.de/
Kriegsstraße 100              tel: +49-721-96201-1
D-76133 Karlsruhe             fax: +49-721-96201-99




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