Daemon¶
Roles¶
The agent daemon spawns threads to handle its different roles:
- Listener Listens for peer daemon, collector, om node and svcmgr requests.
- Monitor Handle cluster-wide service start and failover decisions and actions.
- Scheduler Periodically run node and services schedulers.
- Heartbeat threads Check if peers are alive and exchange node and service information. Run the quorum race on split-brain.
- Collector Send cluster information to the collector. Only one node in the cluster sends. This role fails over transparently.
See also
Daemon management¶
Start¶
$ om node daemon start
On systems using systemd, the start is delegated to the systemd opensvc-agent unit, which triggers a om node daemon start.
Stop¶
$ om node daemon stop
The node advertizes its entering maintenance mode, so peer nodes will preserve the node's last known data until the node.maintenance_grace_period expires.
Restart¶
$ om node daemon restart
The node advertizes its entering maintenance mode, so peer nodes will preserve the node's last known data until the maintenance_grace_period expires.
On systems using systemd, the restart is delegated to the systemd opensvc-agent unit, which triggers a om node daemon stop followed by a om node daemon start.