Hi OVN,
May be another question on top. :)
>From [1] In the HA_Chassis_Group Table:
ref_chassis: set of weak reference to Chassis
The set of Chassis that reference this HA chassis group. To
determine the correct Chassis, find the chassisredirect type
Port_Binding that references this HA_Chassis_Group. This
Port_Binding is derived from some particular logical router.
Starting from that LR, find the set of all logical switches and
routers connected to it, directly or indirectly, across router
ports that link one LRP to another or to a LSP. For each LSP in
these logical switches, find the corresponding Port_Binding and
add its bound Chassis (if any) to ref_chassis.
What is meant by "indirectly" in the above text? And why do we need it to keep
track of indirect connections?
Because for us that results in a long(possibly full) list of compute chassis in
the `ref_chassis` for each LRP, which hurts us during recompute as Max
mentioned below. :)
Thanks!
[1] https://www.ovn.org/support/dist-docs/ovn-sb.5.html
Kind regards,
Ihtisham ul Haq
-----Original Message-----
From: discuss <ovs-discuss-boun...@openvswitch.org> On Behalf Of Max André
Lamprecht via discuss
Sent: Wednesday, May 31, 2023 4:40 PM
To: ovs-discuss@openvswitch.org
Subject: [ovs-discuss] northd: amount of ref_chassis in ha_chassis_group
Hi,
We noticed in a large openstack cluster (~500 Chassis) that during a
VIP(attached with a floating ip) failover it takes up to 50 seconds until the
traffic gets routed to the correct port.
That is caused due to the slow Logical_Flow update in the southbound db. Before
that update happens all the FIP traffic will be still forwarded to the previous
vip port.
inc_proc_eng|INFO|node: northd, recompute (forced) took 20502ms
inc_proc_eng|INFO|node: lflow, recompute (forced) took 802ms
This lflow gets updated by northd. During debugging we discovered that northd
spends a large amount of time at recomputing ref_chassis in the
HA_Chassis_Group table.
ovnsb_db_run (inlined)
-handle_port_binding_changes (inlined)
- 10.53% build_ha_chassis_group_ref_chassis (inlined)
8.84% add_to_ha_ref_chassis_info (inlined)
0.69% hmap_next (inlined)
Maybe this is special to our environment because we have a few external
stretched l2 networks represented as Logical_Switch.
To these Logical_Switches there are many Logical_Router_Ports attached. e.g.
~3500 LRPs are attached to one LS.
compute vm -> internal net -> router -> external net(type=localnet) > N Routers
C1 -> LS1 -> R1 -> LS2 -> R2..RN -> LS2..LSN -> C2..CN
Currently we can see that northd adds about ~500 Chassis to each ref_chassis
column. I think that this is too much and not nessasary. Pls correct me if I´m
wrong :)
If I see this right ref_chassis is only taken to decide where to build the BFD
sessions to.
Is there a reason why this needs to be referenced across chassisredirect ports
and further?
Does it make sense that we stop the whole lookup process in
build_lrouter_groups__() if we have a lrp with a chassis-redirect-port set?
Thanks for your time
Max
Diese E Mail enthält möglicherweise vertrauliche Inhalte und ist nur für die
Verwertung durch den vorgesehenen Empfänger bestimmt.
Sollten Sie nicht der vorgesehene Empfänger sein, setzen Sie den Absender bitte
unverzüglich in Kenntnis und löschen diese E Mail.
Hinweise zum Datenschutz finden Sie hier<https://www.datenschutz.schwarz/>.
This e-mail may contain confidential content and is intended only for the
specified recipient/s.
If you are not the intended recipient, please inform the sender immediately and
delete this e-mail.
Information on data protection can be found
here<https://www.datenschutz.schwarz/>.
_______________________________________________
discuss mailing list
disc...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
Diese E Mail enthält möglicherweise vertrauliche Inhalte und ist nur für die
Verwertung durch den vorgesehenen Empfänger bestimmt.
Sollten Sie nicht der vorgesehene Empfänger sein, setzen Sie den Absender bitte
unverzüglich in Kenntnis und löschen diese E Mail.
Hinweise zum Datenschutz finden Sie hier<https://www.datenschutz.schwarz/>.
This e-mail may contain confidential content and is intended only for the
specified recipient/s.
If you are not the intended recipient, please inform the sender immediately and
delete this e-mail.
Information on data protection can be found
here<https://www.datenschutz.schwarz/>.
_______________________________________________
discuss mailing list
disc...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
