3.5.1 Matrix Server Administration Guide

Chapter 12: Configure Virtual Hosts 218

You can use the following Advanced settings to affect how ClusterPulse

selects the network interface for failover.

• The Event Severity setting allows you to specify whether ClusterPulse

should consider the existence of monitor events (such as a script

failure or timeout) when it chooses a network interface for failover. If

the events are considered, the network interface for the affected server

becomes less desirable.

• For service monitors, you can assign a priority to each monitor (the

Service Priority setting). If ClusterPulse cannot locate an interface

where all services are “up” on the underlying server, it selects an

interface where the highest priority service is “up” on the underlying

server.

Specify Failback Behavior of the Virtual Host

When you configure a virtual host, you can specify the failback action

that the virtual host will take following a failover to a backup server.

There are two options:

AUTOFAILBACK and NOFAILBACK.

AUTOFAILBACK is the default for virtual hosts. (Some PolyServe products

may provide entities that use

NOFAILBACK as the default.)

AUTOFAILBACK

AUTOFAILBACK is intended to return the virtual host to its original

configuration, or as close to it as possible. After the virtual host fails over

to a backup server, ClusterPulse watches the health of the servers higher

in the list for that virtual host. When the health of one of these servers is

equal to or greater than the backup server where the virtual host currently

resides, the virtual host automatically attempts to fail over to that server.

NOFAILBACK

NOFAILBACK is intended to minimize failovers. The virtual host remains

active on the backup server until a healthier server (it’s health is greater

than the backup server) becomes available, at which point the virtual host

will fail over to that server.

For example, consider a two-node matrix that is configured with its

primary on node 1 and backup on node 2, and that uses the

NOFAILBACK

option. Three service monitors are configured on the virtual host. When a