Hi @rdesoju,
A list of events can be found here: SolOS-TR Message Bus Management Syslog Events
From what you’re requesting I would start by looking at the events under SYSTEM → SYSTEM_AD and SYSTEM → SYSTEM_HA. For example I think you might be interested in SYSTEM_HA_REDUN_GROUP_NODE_JOINED
I would also recommend you take a look at events under VPN → VPN_AD so you’re aware of message spool, endpoint usage, etc. at the individual vpn level.
Hope that helps!
-Marc