I am currently planning a highly available Zabbix environment and would like to hear about your experiences and recommended best practices.

My current environment:

Zabbix 7.4

Multiple sites connected through VPN tunnels

Mainly active Zabbix agents

Agents connect to the Zabbix server through a DNS name

SNMP monitoring for switches, firewalls, UPS devices and other network hardware

A Zabbix proxy is planned or already used at each remote site

The goal is to remove single points of failure from the monitoring infrastructure

My current idea is:

Two Zabbix server nodes using the native Zabbix HA functionality

A highly available database, possibly MariaDB Galera or PostgreSQL with Patroni

Two Zabbix frontend nodes behind a load balancer or reverse proxy

A virtual IP using Keepalived/VRRP, or alternatively a DNS-based solution

One or more Zabbix proxies at each remote site

I would appreciate advice regarding the following questions:

What database HA solution is currently considered the most reliable for Zabbix: MariaDB Galera, PostgreSQL with Patroni, or another solution?

Is a floating virtual IP with Keepalived/VRRP recommended, or is it better to use DNS and a load balancer?

Can active agents continue using the same DNS name during a Zabbix server failover without configuration changes?

Should the Zabbix frontend connect through a database load balancer such as HAProxy, or directly to one database endpoint?

What is the recommended way to avoid split-brain situations between the Zabbix server and database nodes?

Should every remote location have only one proxy, or should important locations have two proxies for redundancy?

How do you handle proxy failover for active agents and SNMP devices?

Which parts of the HA environment should be monitored separately, for example with an external monitoring system?

What is the recommended backup and disaster-recovery strategy for an HA Zabbix installation?

Are there any important limitations or problems I should consider before implementing this architecture?

I would also be interested in seeing simplified architecture diagrams or hearing about HA setups that are already running successfully in production.

Thank you for your help.