Cisco Cisco Email Security Appliance X1050 Guía Del Usuario
38-3
Cisco AsyncOS 8.5.5 for Email Security User Guide
Chapter 38 Centralized Management Using Clusters
Cluster Organization
Figure 38-1
Cluster Level Hierarchy
Within each level there will be one or more specific members for which settings may be configured; these
are referred to as modes. A mode refers to a named member at a specified level. For example, the group
“usa” represents one of two group modes in the diagram.
are referred to as modes. A mode refers to a named member at a specified level. For example, the group
“usa” represents one of two group modes in the diagram.
While levels are a general term, modes are
specific; modes are always referred to by name. The cluster depicted in
has six modes.
Although settings are configured at a given level, they are always configured for a specific mode. It is
not necessary to configure settings for all modes within a level. The cluster mode is a special case.
Because there can only be one cluster, all settings configured for the cluster mode can be said to be
configured at the cluster level.
not necessary to configure settings for all modes within a level. The cluster mode is a special case.
Because there can only be one cluster, all settings configured for the cluster mode can be said to be
configured at the cluster level.
You should normally configure most settings at the cluster level. However, settings that have been
specifically configured at lower levels will override settings configured at higher levels. Thus, you can
override cluster-mode settings with group-mode or machine-mode settings.
specifically configured at lower levels will override settings configured at higher levels. Thus, you can
override cluster-mode settings with group-mode or machine-mode settings.
For example, you might start by configuring the Good Neighbor Table in cluster mode; all machines in
the cluster would use that configuration. Then, you might also configure this table in machine mode for
machine
the cluster would use that configuration. Then, you might also configure this table in machine mode for
machine
newyork
. In this case, all other machines in the cluster will still use the good neighbor table
defined at the cluster level, but the machine
newyork
will override the cluster settings with its individual
machine mode settings.
The ability to override cluster settings for specific groups or machines gives you a lot of flexibility.
However, if you find yourself configuring many settings individually in machine mode, you will lose
much of the ease of administration that clusters were intended to provide.
However, if you find yourself configuring many settings individually in machine mode, you will lose
much of the ease of administration that clusters were intended to provide.
Initial Configuration Settings
For most features, when you begin to configure settings for a new mode, those settings will initially be
empty by default. There is a distinction between empty settings and having no settings in a mode. As an
example, consider a very simple cluster composed of one group and one machine. Imagine that you have
an LDAP query configured at the cluster level. There are no settings configured at the group or machine
levels:
empty by default. There is a distinction between empty settings and having no settings in a mode. As an
example, consider a very simple cluster composed of one group and one machine. Imagine that you have
an LDAP query configured at the cluster level. There are no settings configured at the group or machine
levels:
newyork.example.com
losangeles.example.com
toronto.example.com
canada
usa
americas
Machine Level
Group Level
Cluster Level
Cluster
(ldap queries: a, b, c)
Group
Machine