Role
The poller daemon launches check plugins as requested by schedulers. When the check is finished it returns the result to the schedulers. Pollers can be tagged for specialized checks (ex. Windows versus Unix, customer A versus customer B, DMZ). There can be many pollers for load-balancing or hot standby spare roles.
Other daemon connexions
The poller get its configuration from the Arbiter daemon, by default on its 7771 port.
The configuration is the realm scheduler list where the poller will have to connect.
DMZ Poller
It's possible to set poller in a DMZ zone, and the schedulers into the LAN. In this situation, the goal is to avoid DMZ (poller) to LAN (schedulers) connexions. In this case, it's possible to set the poller as passive. In this case, the scheduler will open a connexion to the poller.
This is the recommanded setup in a DMZ.
Only checks for host in this DMZ will be launched by this poller.
Data
The poller get command from the schedulers.
It do not known about hosts or checks. It only get commands to execute, and the commands are created by the schedulers.
It's important to note that the plugins launched by the pollers will have a direct access to the monitored hosts, and they will need to get data from them.
Poller connexions summary
| source | Destination | Port | Protocol | Note |
|---|---|---|---|---|
| Poller | Scheduler | 7768 | HTTPS |