HP Serviceguard manual Service Assistant Daemon cmserviced, Quorum Server Daemon qs

Generic resources allows custom defined monitors to be integrated. It provides better control, options, and flexibility in terms of getting and setting the status of a resource.

This daemon is used by the Serviceguard commands cmgetresource(1m) and cmsetresource(1m) to get or set the status/value of a simple/extended generic resource configured in a package and is local to a node. This daemon runs on every node on which cmcld is running.

Service Assistant Daemon: cmserviced

This daemon forks and execs any scripts or processes 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 cmserviced or it causes the package to halt and moves the package to an available alternate node.

Quorum Server Daemon: qs

Using a Quorum Server is one way to break a tie and establish a quorum when the cluster is re-forming; the other way is to use a cluster lock. See “Cluster Quorum to Prevent Split-Brain Syndrome” and “Cluster Lock ” (page 46).

The Quorum Server, if used, runs on a system external to the cluster and is started by the system administrator, not by Serviceguard. It is normally started from /etc/inittab with the respawn option, which means that it automatically restarts if it fails or is killed. All members of the cluster initiate and maintain a connection to the Quorum Server; if it dies, the Serviceguard nodes will detect this and then periodically try to reconnect to it. If there is a cluster re-formation while the Quorum Server is down and tie-breaking is needed, the re-formation will fail and all the nodes will halt (system reset). For this reason it is important to bring the Quorum Server back up as soon as possible.

For more information about the Quorum Server software and how it works, see the latest version of the HP Serviceguard Quorum Server release notes at http://www.hp.com/go/ hpux-serviceguard-docs under HP Serviceguard Quorum Server Software

Network Manager Daemon: cmnetd

This daemon monitors the health of cluster networks, and performs local LAN failover. It also handles the addition and deletion of relocatable package IP addresses for both IPv4 and IPv6.

Lock LUN Daemon: cmdisklockd

If a lock LUN is being used, cmdisklockd runs on each node in the cluster and is started by cmcld when the node joins the cluster.

Utility Daemon: cmlockd

Runs on every node on which cmcld is running (though currently not actually used by Serviceguard on HP-UX systems).

Cluster WBEM Agent Daemon: cmwbemd

This daemon collaborates with the Serviceguard WBEM provider plug-in module (SGProviders) and WBEM services cimserver to provide notification (WBEM Indications) of Serviceguard cluster events to Serviceguard WBEM Indication subscribers that have registered a subscription with the cimserver. For example, an Indication is sent when the cluster configuration changes, or when a Serviceguard package has failed.

Serviceguard Architecture 43