* Jimmy Hess:
On Wed, Jul 20, 2011 at 9:31 AM, Nick Colton <ncolton@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@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