This one of the most important articles about the clustered Zabbix monitoring. It’s about common terminology and architecture.
When there is a classical server with a set of proxies, there is a strict host-> server or host -> proxy relation. This is done by setting the proxy attribute to a host in Zabbix configuration panels.
But when we have a cluster, then we would like to bound a host to a set of servers or proxies. And this is what “monitoring domains” for.
So, a “monitoring domain” is an identifier of set of proxies and servers which should be used to process a certain host.
A monitoring domain name may look just like an ordinary internet domain name “service.example.org” or you may use any kind of string which is valid for domain name like “server_farm1_major_hosts”, however the first one looks better.
Let’s look from a user’s perspective to “monitoring domains”.
Say, one got a server in the central office and two proxies in two branches.
In a classic configuration this might be a server and two proxies.
Hosts from branch1 are bound to proxy1 just as hosts in the branch2 are set to be monitored from proxy in branch2. All hosts from central office doesn’t have a proxy set, so they are monitored directly by the server.
In a clustered architecture for such a case you would want to define three domains – central_office, branch1 and branch2. Since cluster is an option thenm, perhaps, there are reasons for making redundant structure.