3.5.1 Matrix Server Administration Guide

Chapter 12: Configure Virtual Hosts 216

• A server is considered down if it loses coordinated communication

with the matrix (for example, the server crashed or was shut down,

Matrix Server was shut down on that server, the server failed to

schedule a matrix group communication process for an extended

period of time, the server disabled the NIC being used for matrix

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.

4. If the virtual host is currently active on a server and that virtual host

has the

NOFAILBACK policy, then this active server is moved to the

head of the list of preferred servers to be considered.

5. From this list, ClusterPulse tries to find a server with all services up

and enabled. If ClusterPulse finds a server meeting these conditions, it

will use it, preferring servers earlier in the list of servers configured

for the virtual host.

6. If there are no servers with completely healthy services, ClusterPulse

picks a server that has at least one service up and enabled. If the

services have different priorities, ClusterPulse uses a server where a

service with the highest available priority is up. If ClusterPulse finds a

server meeting these conditions, it will use it, preferring servers earlier

in the list of servers configured for the virtual host.

7. If there are no servers with an up and enabled service and the virtual

host is configured with the “Always active” option, ClusterPulse picks

any server from the list.

8. The selected server will have one interface that was configured for this

virtual host. The virtual host will be active on this interface. If

ClusterPulse cannot locate a server meeting these conditions, it does

not place the virtual host anywhere.