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.
DNS powerdns remote backend, serving names for services backend ip addresses.
Collector Send cluster information to the collector. Only one node in the cluster sends. This role fails over transparently.
Voir aussi
Daemon management¶
Start¶
$ om daemon start
On systems using systemd, the start is delegated to the systemd opensvc-agent unit, which triggers a om daemon start.
Stop¶
$ om 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 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 daemon stop followed by a om daemon start.