HA peer split-brain recovery?

[TranceforLife]

Hi Guys,

l came across this nice article where Mivaldi explains what is peer split-brain

https://live.paloaltonetworks.com/t5/General-Topics/What-is-Peer-Split-Brain/m-p/19825#U19825

I have a question. 

We don't have HA1 backup link configured and our Heartbeat Backup (mgmt port) were  not reachable between to PAs. This is all to the switch issue between the devices. Passive node went to Active. So peer split-brain occurred. Just to confirm when HA1 heartbeat recovered ( say network connection is restored between the devices) will my "Active" node become back to "Passive". If you can clear this would be great. Logs below:

2016-08-25 00:59:39.706 +0100 Error: ha_ping_peer_miss(src/ha_ping.c:756): Missed 1 ping timeouts out of 3 (ha1)
2016-08-25 00:59:39.706 +0100 Error: ha_ping_peer_miss(src/ha_ping.c:756): Missed 1 ping timeouts out of 3 (mgmt)
2016-08-25 00:59:40.706 +0100 Error: ha_ping_peer_miss(src/ha_ping.c:756): Missed 2 ping timeouts out of 3 (ha1)
2016-08-25 00:59:40.706 +0100 Error: ha_ping_peer_miss(src/ha_ping.c:756): Missed 2 ping timeouts out of 3 (mgmt)
2016-08-25 00:59:41.707 +0100 Error: ha_ping_peer_miss(src/ha_ping.c:756): Missed 3 ping timeouts out of 3 (ha1)
2016-08-25 00:59:41.707 +0100 Error: ha_ping_peer_miss(src/ha_ping.c:763): We have missed 4 pings from the peer for group 1 (ha1), restarting connection
2016-08-25 00:59:41.709 +0100 Warning: ha_event_log(src/ha_event.c:47): HA Group 1: HA1 connection down
2016-08-25 00:59:41.709 +0100 Warning: ha_event_log(src/ha_event.c:47): HA Group 1: All HA1 connections down

Thx,

Myky

[jdelio · Accepted solution]

@TranceforLife,

Sorry for any confusion.. 

As far as which unit will become active after communication has been restored to both members.. the following applies:

1. If you want to control which member becomes active first, you have to configure the Preemtive settings in Device > High Availability > General > Election Settings. 
Note: The member with the Lower number has Priority in the HA Pair.

2. If you do not configure this, then it would be whichever member is determined to be available first, which is basically a random thing.

In general, if you would like to control this behavior, then that is why the Preemtive settings are there for. 

[TranceforLife]

Cool. Thx