Mailing List Archive

[lvs-users] thoughts on making IPVS sync multicast address adjustable
Has any thought been giving to making the multicast address IPVS sync
daemons use to sync state be configurable?

224.0.0.81 is in the link local multicast subnet. Our hope is to have
the IPVS directors be distributed in multiple L3 networks so the
multicast traffic would have to be routed between them. This wouldn't
be a problem except for the choice of this link-local subnet is
treated specially by network vendors. Routing devices do not want to
route this and according to my network folks it would cause it to hit
the control plane and cause excessive usage on the routers where an
alternate multicast subnet would not.

Looking at the code it would appear some what trivial to change this
to a proc setting but I do not know the context or history of the
choice behind 224.0.0.81 as the address to be hard coded.
Interestingly the IANA assignments document shows the .81 address as
being in a reserved range.

Our configuration idea is to have a small pool of directors all acting
as master and backup (running both daemons). We will anycast with
BGP/exabgp the VIP addresses to live on all of the directors which
would live on several subnets.

I appreciate any thoughts or feedback on this idea or experiences with
using the existing address at scale.

Thanks,
Phillip Moore

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Re: [lvs-users] thoughts on making IPVS sync multicast address adjustable [ In reply to ]
Hi Phillip,

On Tue, Jun 30, 2015 at 03:59:12PM -0500, Phillip Moore wrote:
> Has any thought been giving to making the multicast address IPVS sync
> daemons use to sync state be configurable?
>
> 224.0.0.81 is in the link local multicast subnet. Our hope is to have
> the IPVS directors be distributed in multiple L3 networks so the
> multicast traffic would have to be routed between them. This wouldn't
> be a problem except for the choice of this link-local subnet is
> treated specially by network vendors. Routing devices do not want to
> route this and according to my network folks it would cause it to hit
> the control plane and cause excessive usage on the routers where an
> alternate multicast subnet would not.
>
> Looking at the code it would appear some what trivial to change this
> to a proc setting but I do not know the context or history of the
> choice behind 224.0.0.81 as the address to be hard coded.
> Interestingly the IANA assignments document shows the .81 address as
> being in a reserved range.
>
> Our configuration idea is to have a small pool of directors all acting
> as master and backup (running both daemons). We will anycast with
> BGP/exabgp the VIP addresses to live on all of the directors which
> would live on several subnets.
>
> I appreciate any thoughts or feedback on this idea or experiences with
> using the existing address at scale.

I would be happy to review patches from you (or anyone else) to add the
feature you describe above. I would guess that it should be configured via
the netlink mechanism IPVS uses for other portions of its configuration.

_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/

LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org
Send requests to lvs-users-request@LinuxVirtualServer.org
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
Re: [lvs-users] thoughts on making IPVS sync multicast address adjustable [ In reply to ]
Hello,

On Tue, 30 Jun 2015, Phillip Moore wrote:

> Has any thought been giving to making the multicast address IPVS sync
> daemons use to sync state be configurable?
>
> 224.0.0.81 is in the link local multicast subnet. Our hope is to have
> the IPVS directors be distributed in multiple L3 networks so the
> multicast traffic would have to be routed between them. This wouldn't
> be a problem except for the choice of this link-local subnet is
> treated specially by network vendors. Routing devices do not want to
> route this and according to my network folks it would cause it to hit
> the control plane and cause excessive usage on the routers where an
> alternate multicast subnet would not.
>
> Looking at the code it would appear some what trivial to change this
> to a proc setting but I do not know the context or history of the
> choice behind 224.0.0.81 as the address to be hard coded.
> Interestingly the IANA assignments document shows the .81 address as
> being in a reserved range.
>
> Our configuration idea is to have a small pool of directors all acting
> as master and backup (running both daemons). We will anycast with
> BGP/exabgp the VIP addresses to live on all of the directors which
> would live on several subnets.
>
> I appreciate any thoughts or feedback on this idea or experiences with
> using the existing address at scale.

I planned a change for sync code to configure message
size. But waited the merge window, so I can try this weekend
to implement also this feature: IP, PORT, TTL, the
224.0.0.81:8848/1 being default. As Simon suggests, may be
with new attributes for the IPVS_CMD_ATTR_DAEMON message.
I can try it to support IPv6 too.

Regards

--
Julian Anastasov <ja@ssi.bg>

_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/

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Send requests to lvs-users-request@LinuxVirtualServer.org
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
Re: [lvs-users] thoughts on making IPVS sync multicast address adjustable [ In reply to ]
Hi Julian,

Were you saying you might could make this change as part of other
changes you are already working on? If so awesome! I would be happy
to help in anyway you would find helpful. If not I will endeavor to
accomplish this on my own.

Thanks,
Phillip Moore

On Wed, Jul 1, 2015 at 2:33 AM, Julian Anastasov <ja@ssi.bg> wrote:

> I planned a change for sync code to configure message
> size. But waited the merge window, so I can try this weekend
> to implement also this feature: IP, PORT, TTL, the
> 224.0.0.81:8848/1 being default. As Simon suggests, may be
> with new attributes for the IPVS_CMD_ATTR_DAEMON message.
> I can try it to support IPv6 too.
>
> Regards
>
> --
> Julian Anastasov <ja@ssi.bg>

_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/

LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org
Send requests to lvs-users-request@LinuxVirtualServer.org
or go to http://lists.graemef.net/mailman/listinfo/lvs-users
Re: [lvs-users] thoughts on making IPVS sync multicast address adjustable [ In reply to ]
Hello,

On Tue, 7 Jul 2015, Phillip Moore wrote:

> Hi Julian,
>
> Were you saying you might could make this change as part of other
> changes you are already working on? If so awesome! I would be happy
> to help in anyway you would find helpful. If not I will endeavor to
> accomplish this on my own.

I'm almost ready with the patch, will send soon
in case you want to test it. But for final submission it
will need more time because other patches for IPVS wait
net-next to open...

Regards

--
Julian Anastasov <ja@ssi.bg>

_______________________________________________
Please read the documentation before posting - it's available at:
http://www.linuxvirtualserver.org/

LinuxVirtualServer.org mailing list - lvs-users@LinuxVirtualServer.org
Send requests to lvs-users-request@LinuxVirtualServer.org
or go to http://lists.graemef.net/mailman/listinfo/lvs-users