| 2023-06-20 09:48:49 |
Ihtisham ul Haq |
description |
Consider the following
Router Priority Chassis
r_a 5 gtw06
r_a 4 gtw05
r_a 3 gtw04
r_a 2 gtw03
r_a 1 gtw02
Note the r_a doesn't have any priority on gtw01 but now if we stop gtw06(using ovn-appctl exit) due to maintenance reasons, afterwards the situation becomes:
Router Priority Chassis
r_a 5 gtw05
r_a 4 gtw04
r_a 3 gtw03
r_a 2 gtw02
r_a 1 gtw01
So basically neutron slides down the priorities for that router, when it detects that chassis(gtw06) is down, and I believe it does that to avoid moving the active LRP more then once, as the router is already failed over to prioity 4(gtw05), and when the gtw06 goes down and afterwards it only updates gtw05 to priority 5 and similarly for the other priorities<5.
And the issue arises because of that is when we have many priority 5 routers on gtw06, and the rescheduling(due to failover of the chassis) doesn't result in a balanced distribution of the routers. And to resolve that we currently have to run another external script to rebalances the LRPs.
I am not yet sure if that is case by design and the operator has to make sure they routers are rebalanced manually or if there is better solution here so we have rebalanced the LRP while keeping in mind to have least amount of failovers for the LRP.
Neutron version: Yoga |
Consider the following
Router Priority Chassis
r_a 5 gtw06
r_a 4 gtw05
r_a 3 gtw04
r_a 2 gtw03
r_a 1 gtw02
Note the r_a doesn't have any priority on gtw01 but now if we stop gtw06(using ovn-appctl exit) due to maintenance reasons, afterwards the situation becomes:
Router Priority Chassis
r_a 5 gtw05
r_a 4 gtw04
r_a 3 gtw03
r_a 2 gtw02
r_a 1 gtw01
So basically neutron promotes the priorities for that router, when it detects that chassis(gtw06) is down, and I believe it does that to avoid moving the active LRP more then once, as the router is already failed over to priority 4(gtw05), and when the gtw06 goes down and afterwards it only updates gtw05 to priority 5 and similarly for the other priorities<5.
And the issue arises because of that is when we have many priority 5 routers on gtw06, and the rescheduling(due to failover of the chassis) doesn't result in a balanced distribution of the routers. And to resolve that we currently have to run another external script to rebalances the LRPs.
I am not yet sure if that is case by design and the operator has to make sure they routers are rebalanced manually or if there is better solution here so we have rebalanced the LRP while keeping in mind to have least amount of failovers for the LRP.
Neutron version: Yoga |
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