I am running several services in Amazon Web Services (AWS), with three application servers per service instance. Each of these services has an Elastic Load Balancer (ELB) in front of it, to distribute traffic among the three application servers. I have Zabbix agents running on each of the application servers; Zabbix hosts have been defined for these application servers and I am able to monitor them without a problem. The Amazon ELBs are configured with a DNS CNAME as an entry point and each one has a single TCP port open on it, which is then distributed across the three application servers on the backend.

I need to be able to monitor the TCP port open on the load balancer and the data it returns in order to be able to determine if the service as a whole is up or down. Since we are load balancing across three application servers, as long as one application server is up and running, the service presented through the load balancer will be operational.

The problem I have is that I cannot create Zabbix hosts that do not have interfaces. When I remove all interfaces from the host definition, I get the following error message, when I try to save the host:

Since this is an Amazon ELB, it cannot run a Zabbix agent and it does not present SNMP, JMX or IPMI ports for monitoring. A series of simple TCP port checks, plus curl scripts to check response data for an "amiup" page will be sufficient to determine if there is at least one healthy server behind the load balancer. The load balancer itself will be running health checks on the servers behind it, which will add or remove hosts that are healthy. The Zabbix Server will be able to execute the simple checks I have in mind, but I cannot save the host in order.

I can save the host with a Zabbix Agent interface definition of 127.0.0.1:10050, but I am concerned that this will be confused with the Zabbix Agent that runs on the Zabbix Server.

How can I properly create hosts that can be used to monitor load balancer ports with simple checks?