Hey team, When using DVR + HA, we endup with all routers beeing deployed on the computes (the DVR part) and 3 routers on dvr_snat nodes (for HA). The question is why 3 for snats? I know that this is the max_l3_agents_per_router config parameter, but 2 seems enough? On the other side, DHCP agent default (dhcp_agents_per_network) is 1, while this is also a precious service provided in the tenant network. So, is there any downside on having only 2 agents for routers? Thanks in advance, Arnaud.
Sorry, forgot to add neutron header Kind regards, Arnaud Le 20 octobre 2021 17:28:39 GMT+02:00, Arnaud Morin <arnaud.morin@gmail.com> a écrit :
Hey team,
When using DVR + HA, we endup with all routers beeing deployed on the computes (the DVR part) and 3 routers on dvr_snat nodes (for HA).
The question is why 3 for snats? I know that this is the max_l3_agents_per_router config parameter, but 2 seems enough?
On the other side, DHCP agent default (dhcp_agents_per_network) is 1, while this is also a precious service provided in the tenant network.
So, is there any downside on having only 2 agents for routers?
Thanks in advance,
Arnaud.
Hi, On Thu, Oct 21, 2021 at 07:34:43AM +0200, Arnaud wrote:
Sorry, forgot to add neutron header
Kind regards, Arnaud
Le 20 octobre 2021 17:28:39 GMT+02:00, Arnaud Morin <arnaud.morin@gmail.com> a écrit :
Hey team,
When using DVR + HA, we endup with all routers beeing deployed on the computes (the DVR part) and 3 routers on dvr_snat nodes (for HA).
The question is why 3 for snats? I know that this is the max_l3_agents_per_router config parameter, but 2 seems enough?
On the other side, DHCP agent default (dhcp_agents_per_network) is 1, while this is also a precious service provided in the tenant network.
So, is there any downside on having only 2 agents for routers?
TBH I don't think there is any downside to have only 2 agents hosting each router (SNAT in case of DVR). Actually this is what we are e.g. testing in the neutron-ovs-tempest-dvr-ha-multinode-full job as we have only 2 nodes there.
Thanks in advance,
Arnaud.
-- Slawek Kaplonski Principal Software Engineer Red Hat
Thanks slawek, Actually, we dig a little bit into code: https://review.opendev.org/c/openstack/neutron/+/64553 In patchet 59, a discussion between Carl and Assaf seems to be the decision of having 3: - "An additional standby could help certain topologies though I'm sure." - "Fair enough" Cheers, On 21.10.21 - 08:49, Slawek Kaplonski wrote:
Hi,
On Thu, Oct 21, 2021 at 07:34:43AM +0200, Arnaud wrote:
Sorry, forgot to add neutron header
Kind regards, Arnaud
Le 20 octobre 2021 17:28:39 GMT+02:00, Arnaud Morin <arnaud.morin@gmail.com> a écrit :
Hey team,
When using DVR + HA, we endup with all routers beeing deployed on the computes (the DVR part) and 3 routers on dvr_snat nodes (for HA).
The question is why 3 for snats? I know that this is the max_l3_agents_per_router config parameter, but 2 seems enough?
On the other side, DHCP agent default (dhcp_agents_per_network) is 1, while this is also a precious service provided in the tenant network.
So, is there any downside on having only 2 agents for routers?
TBH I don't think there is any downside to have only 2 agents hosting each router (SNAT in case of DVR). Actually this is what we are e.g. testing in the neutron-ovs-tempest-dvr-ha-multinode-full job as we have only 2 nodes there.
Thanks in advance,
Arnaud.
-- Slawek Kaplonski Principal Software Engineer Red Hat
Hi, On czwartek, 21 października 2021 11:37:09 CEST Arnaud Morin wrote:
Thanks slawek,
Actually, we dig a little bit into code: https://review.opendev.org/c/openstack/neutron/+/64553
In patchet 59, a discussion between Carl and Assaf seems to be the decision of having 3: - "An additional standby could help certain topologies though I'm sure." - "Fair enough"
WOW, You dig deep to find that :) Thx a lot.
Cheers,
On 21.10.21 - 08:49, Slawek Kaplonski wrote:
Hi,
On Thu, Oct 21, 2021 at 07:34:43AM +0200, Arnaud wrote:
Sorry, forgot to add neutron header
Kind regards, Arnaud
Le 20 octobre 2021 17:28:39 GMT+02:00, Arnaud Morin
<arnaud.morin@gmail.com> a écrit :
Hey team,
When using DVR + HA, we endup with all routers beeing deployed on the computes (the DVR part) and 3 routers on dvr_snat nodes (for HA).
The question is why 3 for snats? I know that this is the max_l3_agents_per_router config parameter, but 2 seems enough?
On the other side, DHCP agent default (dhcp_agents_per_network) is 1, while this is also a precious service provided in the tenant network.
So, is there any downside on having only 2 agents for routers?
TBH I don't think there is any downside to have only 2 agents hosting each router (SNAT in case of DVR). Actually this is what we are e.g. testing in the neutron-ovs-tempest-dvr-ha-multinode-full job as we have only 2 nodes there.>
Thanks in advance,
Arnaud.
-- Slawek Kaplonski Principal Software Engineer Red Hat
participants (3)
-
Arnaud
-
Arnaud Morin
-
Slawek Kaplonski