Add scope without service restart, possible? (Follow-up)

Fri May 29 16:28:02 UTC 2020

Thank you all for the very informative replies.

I have to admit that I don't have experience with dual servers with
failover setup so if you could share more info, that'll be really great.
Maybe not only for me but for others also.

But just wanted to get this off my mind - so if I have 2 servers in
failover mode, I could update configs in the Primary server and restart
dhcpd service on it but will not have service downtime to DHCP clients
(existing and new)?

@Steve van der Burg, really interested to know more how you push new
configs to both servers (manual or automated?) and then the servers test
them and, if they pass, restart on alternate minutes.

@Patrick Trapp, I really think a lot of us here could benefit from your
workflow.

Thank you

Jef

On Sat, May 23, 2020 at 5:44 AM <dhcp-users-request at lists.isc.org> wrote:

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> Today's Topics:
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>    1. Re: Add scope without service restart, possible? (Simon Hobson)
>    2. RE: Add scope without service restart, possible?
>       (Steve van der Burg)
>    3. Re: Add scope without service restart, possible? (Patrick Trapp)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 22 May 2020 20:22:14 +0100
> From: Simon Hobson <dhcp1 at thehobsons.co.uk>
> To: Users of ISC DHCP <dhcp-users at lists.isc.org>
> Subject: Re: Add scope without service restart, possible?
> Message-ID: <B329B452-5475-4929-B042-85BAAFCE3CAB at thehobsons.co.uk>
> Content-Type: text/plain; charset=us-ascii
>
> Cayab, Jefrey E. <jcayab at gmail.com> wrote:
>
> > Wanted to check if it's possible to add new DHCP scope to a running
> DHCPd service and to take effect without restart the service? Is there a
> reload equivalent that can take in the updated config?
>
> Not with the ISC server. However, a restart should be very quick for any
> reasonable configuration - and if you use dual servers with failover, then
> no interruption in service to end devices.
>
> Simon
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 22 May 2020 19:30:10 +0000
> From: Steve van der Burg <Steve.vanderBurg at lhsc.on.ca>
> To: Users of ISC DHCP <dhcp-users at lists.isc.org>
> Subject: RE: Add scope without service restart, possible?
> Message-ID:
>         <
> YQXPR01MB2326AD7B94E1161FC4EE51BFBAB40 at YQXPR01MB2326.CANPRD01.PROD.OUTLOOK.COM
> >
>
> Content-Type: text/plain; charset="us-ascii"
>
> I run a pair of servers with all leases (~40k active right now, out of
> ~370k defined) in failover pools and routinely change the configs and
> restart with no interruption to service, as Simon just indicated.
>
> I push new configs to both servers and then the servers test them and, if
> they pass, restart on alternate minutes (primary on even minutes, for
> example, and secondary on odd minutes).
>
> ...Steve
>
> -----Original Message-----
> From: dhcp-users <dhcp-users-bounces at lists.isc.org> On Behalf Of Simon
> Hobson
> Sent: Friday,May 22,2020 3:22 PM
> To: Users of ISC DHCP <dhcp-users at lists.isc.org>
> Subject: Re: Add scope without service restart, possible?
>
> CAUTION: This email originated from outside the organization. Do not click
> links or open attachments unless you recognize the sender and know the
> content is safe.
>
> Cayab, Jefrey E. <jcayab at gmail.com> wrote:
>
> > Wanted to check if it's possible to add new DHCP scope to a running
> DHCPd service and to take effect without restart the service? Is there a
> reload equivalent that can take in the updated config?
>
> Not with the ISC server. However, a restart should be very quick for any
> reasonable configuration - and if you use dual servers with failover, then
> no interruption in service to end devices.
>
> Simon
>
> _______________________________________________
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> ------------------------------
>
> Message: 3
> Date: Fri, 22 May 2020 21:44:15 +0000
> From: Patrick Trapp <ptrapp at nex-tech.com>
> To: Users of ISC DHCP <dhcp-users at lists.isc.org>
> Subject: Re: Add scope without service restart, possible?
> Message-ID:
>         <
> DM6PR12MB3577A9078E41E04A79D0A2D9E6B40 at DM6PR12MB3577.namprd12.prod.outlook.com
> >
>
> Content-Type: text/plain; charset="us-ascii"
>
> I can second that. We run a pair of servers plus a staging server. We make
> changes and test the code on the staging server. If it passes, we sync to a
> git server. We run a script that causes the production servers to pull the
> new config from git and restart, one at a time.
> ________________________________
> From: dhcp-users <dhcp-users-bounces at lists.isc.org> on behalf of Steve
> van der Burg <Steve.vanderBurg at lhsc.on.ca>
> Sent: Friday, May 22, 2020 2:30 PM
> To: Users of ISC DHCP <dhcp-users at lists.isc.org>
> Subject: RE: Add scope without service restart, possible?
>
> CAUTION: This email originated from outside of the company. Do not click
> links or open attachments unless you recognize the sender and know the
> content is safe.
>
> I run a pair of servers with all leases (~40k active right now, out of
> ~370k defined) in failover pools and routinely change the configs and
> restart with no interruption to service, as Simon just indicated.
>
> I push new configs to both servers and then the servers test them and, if
> they pass, restart on alternate minutes (primary on even minutes, for
> example, and secondary on odd minutes).
>
> ...Steve
>
> -----Original Message-----
> From: dhcp-users <dhcp-users-bounces at lists.isc.org> On Behalf Of Simon
> Hobson
> Sent: Friday,May 22,2020 3:22 PM
> To: Users of ISC DHCP <dhcp-users at lists.isc.org>
> Subject: Re: Add scope without service restart, possible?
>
> CAUTION: This email originated from outside the organization. Do not click
> links or open attachments unless you recognize the sender and know the
> content is safe.
>
> Cayab, Jefrey E. <jcayab at gmail.com> wrote:
>
> > Wanted to check if it's possible to add new DHCP scope to a running
> DHCPd service and to take effect without restart the service? Is there a
> reload equivalent that can take in the updated config?
>
> Not with the ISC server. However, a restart should be very quick for any
> reasonable configuration - and if you use dual servers with failover, then
> no interruption in service to end devices.
>
> Simon
>
> _______________________________________________
> ISC funds the development of this software with paid support
> subscriptions. Contact us at https://www.isc.org/contact/ for more
> information.
>
> dhcp-users mailing list
> dhcp-users at lists.isc.org
> https://lists.isc.org/mailman/listinfo/dhcp-users
>
> This email is directed in confidence solely to the person named above and
> may contain confidential, privileged or personal health information. Please
> be aware that this email may also be released to members of the public
> under Ontario's Freedom of Information and Protection of Privacy Act if
> required. Review, distribution, or disclosure of this email by anyone other
> than the person(s) for whom it was originally intended is strictly
> prohibited. If you are not an intended recipient, please notify the sender
> immediately via a return email and destroy all copies of the original
> message. Thank you for your cooperation.
> _______________________________________________
> ISC funds the development of this software with paid support
> subscriptions. Contact us at https://www.isc.org/contact/ for more
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