Managing Serviceguard 12th Edition, March 2006

Understanding Serviceguard Software Components
Serviceguard Architecture
Chapter 3 61
to the object manager and receive responses from it. This daemon may
not be running on your system; it is used only by clients of the object
manager.
cmomd accepts connections from clients, and examines queries. The
queries are decomposed into categories (of classes) which are serviced by
various providers. The providers gather data from various sources,
including, commonly, the cmclconfd daemons on all connected nodes,
returning data to a central assimilation point where it is filtered to meet
the needs of the exact client query. This daemon is started by inetd(1M).
There are entries in the /etc/inetd.conf file.
Cluster SNMP Agent Daemon: cmsnmpd
This daemon is used by the Serviceguard graphic interface (Serviceguard
Manager) to obtain information about the cluster. This daemon produces
the Cluster MIB. Details on the cluster MIB can be found on URL
http://docs.hp.com/hpux/ha under the Frequently Asked Questions area.
This will only be running if the /etc/rc.config.d/cmsnmpagt file has
been edited to autostart this subagent. For proper execution, the
cmsnmpd has to start before the Serviceguard cluster comes up.
Service Assistant Daemon: cmsrvassistd
This daemon forks and execs any script or processes as required by the
cluster daemon, cmcld. There are two type of forks that this daemon
carries out:
• Executing package run and halt scripts
• Launching services
For services, cmcld monitors the service process and, depending on the
number of service retries, cmcld either restarts the service through
cmsrvassistd or it causes the package to halt and moves the package to
an available alternate node.
Quorum Server Daemon: qs
The quorum server daemon provides tie-breaking services when needed
during cluster re-formation. The quorum server runs on a system
external to the cluster, and it is started by the user, not by Serviceguard.
It is normally started out of /etc/inittab, which means that it
automatically re-spawns if it fails or is killed.