[Kea-users] recover from split brain?

[Chad Catlett]

On 2/8/22 14:12, David Ramsey wrote:
> Lab testing I've done shows that the Active/Standby HA configuration 
> works well if one or the other DHCP servers fails completely.  
> Automatic takeover and recovery work nicely.
>
> If an Active/Standby HA implementation were to go "split brain" with 
> core network severed between DHCP servers, however, both would go 
> active and the lease DBs would no longer be in sync.
>
> How to recover from that when the network is restored?  I know there 
> are a ton of variables involved - lease times, how long network was 
> segmented, # subscribers, etc.... but I am wrestling with what would 
> be the optimal approach/logic to consolidate and recover ?
>
> Help?
>
> Thanks folks, --David
>
>
>
>

The admin docs[0] do a fairly decent job of explaining how HA failover 
situations are recovered from. The amount of time it takes is directly 
related to the dhcp statemachine timers, which are influenced by your 
settings.


0: 
https://kea.readthedocs.io/en/kea-2.1.2/arm/hooks.html#scope-transition-in-a-partner-down-case


Chad

-- 
Chad Catlett
chad at catlett.info