default dhcp lease time of 120s is too short

[Brent Eagles]

The default dhcp lease time is fairly short (120s). Is this simply a hold-over from the time before force_dhcp_release was the default and dhcp_release was expected throughout or is there another reason for the default to be so brief?

[Nathanael Burton (mathrock)]

Suggest default of 24 hours.

[Salvatore Orlando (salvatore-orlando)]

It should also be considered that a DHCP request initiated by the host in most cases is the only way for reconfiguring the host upon IP, DNS or static route changes.

At least from the neutron perspective, while 120 seconds is probably too little, 24 hours would probably be unpractical.
I think 10 minutes might be a reasonable default lease time for neutron; DHCP traffic would be a fifth of what it is today, and host reconfiguration upon IP changes would take no more than 10 minutes.

[Darragh O'Reilly (darragh-oreilly)]

Neutron has increased it to 24hr with https://review.openstack.org/#/c/37580/13/neutron/common/config.py

[kesten broughton (dathomir)]

Sorry for the misplaced post, but is there anyway to unsubscribe to the
Openstack Neutron details list?

A month ago i found some list to subscribe to and now get bugs related to
openstack neutron.
I tried the usual channels where my Openstack dev, security counts are
managed but the source of the neutron details was not listed.
The notifications only allow me to unsubscribe to each launchpad bug
individually.
I tried searching gmail for a welcome email from this list.

I get about 15 emails a day non-digest like this
[Bug 1317654] Re: default dhcp lease time of 120s is too short

thanks

kesten

On Mon, May 12, 2014 at 12:17 PM, Salvatore Orlando <
<email address hidden>> wrote:

> It should also be considered that a DHCP request initiated by the host
> in most cases is the only way for reconfiguring the host upon IP, DNS or
> static route changes.
>
> At least from the neutron perspective, while 120 seconds is probably too
> little, 24 hours would probably be unpractical.
> I think 10 minutes might be a reasonable default lease time for neutron;
> DHCP traffic would be a fifth of what it is today, and host reconfiguration
> upon IP changes would take no more than 10 minutes.
>
> ** Also affects: neutron
> Importance: Undecided
> Status: New
>
> ** Changed in: neutron
> Importance: Undecided => Low
>
> ** Changed in: neutron
> Importance: Low => Medium
>
> --
> You received this bug notification because you are subscribed to
> neutron.
> https://bugs.launchpad.net/bugs/1317654
>
> Title:
> default dhcp lease time of 120s is too short
>
> Status in OpenStack Neutron (virtual network service):
> New
> Status in OpenStack Compute (Nova):
> New
>
> Bug description:
> The default dhcp lease time is fairly short (120s). Is this simply a
> hold-over from the time before force_dhcp_release was the default and
> dhcp_release was expected throughout or is there another reason for
> the default to be so brief?
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/neutron/+bug/1317654/+subscriptions
>

[Joe Gordon (jogo)]

Nova should align its default with neutron

[Salvatore Orlando (salvatore-orlando)]

Thanks Darragh for fixing my faulty memory.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/93591
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=23790183d20f59ddcb6025e8497aa16e443bb929
Submitter: Jenkins
Branch: master

commit 23790183d20f59ddcb6025e8497aa16e443bb929
Author: mathrock <email address hidden>
Date: Wed May 14 11:55:33 2014 -0400

    Default dhcp lease time of 120s is too short

    As part of reasonable-defaults, increase the default DHCP
    lease time to a more sane value of 24 hours. This change
    also aligns Nova with the current default DHCP lease time
    in Neutron.

    DocImpact: This changes the default dhcp_lease_time from
    120 seconds to 86400 seconds (24 hours). If the Icehouse
    or previous release behavior is desired, set the config
    dhcp_lease_time to 120.

    Change-Id: Ia666ff31f299c57d46605705e9ebea21630e0722
    Closes-Bug: #1317654