4.1.0 HP PolyServe Matrix Server administration guide (T5392-96073, October 2010)

and enablement of the service and device monitors associated with the virtual host
also contribute to a server’s health calculation. When a server is completely “healthy,”
all of the services associated with the virtual host are up and enabled.
When certain events occur on the server where a virtual host is located, the
ClusterPulse process will attempt to fail over the virtual host to another server
configured for that virtual host. For example, if the server goes down, ClusterPulse
will check the health of the other servers and then determine the best location for the
virtual host.
ClusterPulse uses the following virtual-host activeness policy to determine the server
where it will make a virtual host active. In conjunction with this policy, the decisions
that you make when configuring a virtual host and the service or device monitors
associated with it help determine whether virtual host failover occurs, the interface
to which the virtual host will fail over, and what happens when operations are restored
on the original server.
Virtual host activeness policy
The policy described here is accurate for this release but it may change in future
releases. The virtual host activeness policy is as follows:
1. If the virtual host is disabled, it is not made active anywhere.
2. ClusterPulse considers the list of servers that are both up and enabled and that
are configured for the virtual host. The network interface that the virtual host is
associated with must also be both up and enabled for hosting. Note the following:
• A server that has not finished joining the cluster (see “Server access to the
SAN” on page 241) is not considered up for the purpose of activating the
device monitor.
• A server is considered down if it loses coordinated communication with the
cluster (for example, the server crashed or was shut down, Matrix Server
was shut down on that server, the server failed to schedule a cluster group
communication process for an extended period of time, the server disabled
the NIC being used for cluster network traffic, and so on).
• The PanPulse process controls whether a network interface is marked up or
down. When PanPulse determines that an interface currently hosting a virtual
host is down, ClusterPulse will begin searching for another server on which
to locate the virtual host.
3. ClusterPulse narrows the list to those servers without inactive, down, or disabled
Matrix Server device monitors. If there are no servers that meet this criteria, the
virtual host is not made active anywhere.
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