The scheduler daemon manages the dispatching of checks and actions to the poller and reactionner daemons respectively. The scheduler daemon is also responsible for processing the check result queue, analyzing the results, doing correlation and following up actions accordingly (if a service is down, ask for a host check). It does not launch checks or notifications. It just keeps a queue of pending checks and notifications for other daemons of the architecture (like pollers or reactionners). This permits distributing load equally across many pollers. There can be many schedulers for load-balancing or hot standby roles. Status persistence is achieved using a retention module.
The scheduler daemon open the 7768 port. It will get from it the configuration from the Arbiter daemon at each configuration change.
It will also get on this port the jobs from the other daemons (poller, reactionner and broker). The other daemons are consuming action and data from the scheduler.
In one specific case, the scehduler open connexions to another daemons. This case is when there is a passive poller. this case will be saw on the poller part.
This daemon is hosting the whole configuration. It have access to the whole contact list, but only a part of the realm hosts.
| Source | Destination | Port | Protocol | Note |
|---|---|---|---|---|
| Scheduler | Poller | 7771 | HTTPS | Only if there is a passive poller. |