Monitoring cluster and application service status can help
identify and resolve problems in the cluster environment. The
following tools assist in displaying cluster status
information:
-
The Cluster Status Tool
-
The clustat utility
 |
Important |
| |
Members that are not running the cluster software cannot
determine or report the status of other members of the cluster.
|
Cluster and service status includes the following
information:
The following tables describe how to analyze the status
information shown by the Cluster Status
Tool and the clustat utility.
| Member Status |
Description |
| Member |
| The node is part of the cluster. |
| Note: A node can be a member of a cluster; however, the node
may be inactive and incapable of running services. For example, if
rgmanager is not running on the node, but
all other cluster software components are running in the node, the
node appears as a Member in the Cluster Status Tool. However, without rgmanager running, the node does not appear in the
clustat display. |
|
| Dead |
The member system is unable to participate as a cluster member.
The most basic cluster software is not running on the node. |
Table 4-1. Member Status for the Cluster Status Tool
| Member Status |
Description |
| Online |
The node is communicating with other nodes in the cluster. |
| Inactive |
| The node is unable to communicate with the other nodes in the
cluster. If the node is inactive, clustat
does not display the node. If rgmanager is
not running in a node, the node is inactive. |
| Note: Although a node is inactive, it may still appear as a
Member in the Cluster Status Tool. However, if the node is
inactive, it is incapable of running services. |
|
Table 4-2. Member Status for clustat
| Service Status |
Description |
| Started |
The service resources are configured and available on the
cluster system that owns the service. |
| Pending |
The service has failed on a member and is pending start on
another member. |
| Disabled |
The service has been disabled, and does not have an assigned
owner. A disabled service is never restarted automatically by the
cluster. |
| Stopped |
The service is not running; it is waiting for a member capable
of starting the service. A service remains in the stopped state if
autostart is disabled. |
| Failed |
The service has failed to start on the cluster and cannot
successfully stop the service. A failed service is never restarted
automatically by the cluster. |
Table 4-3. Service Status
The Cluster Status Tool displays the
current cluster status in the Services area
and automatically updates the status every 10 seconds.
Additionally, you can display a snapshot of the current cluster
status from a shell prompt by invoking the clustat utility. Example 4-1 shows
the output of the clustat utility.
# clustat
Member Status: Quorate, Group Member
Member Name State ID
------ ---- ----- --
tng3-2 Online 0x0000000000000002
tng3-1 Online 0x0000000000000001
Service Name Owner (Last) State
-------- ----- ----- ------ -----
webserver (tng3-1 ) failed
email tng3-2 started
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Example 4-1. Output of clustat
To monitor the cluster and display status at specific time
intervals from a shell prompt, invoke clustat with the -i time option, where time specifies the number of seconds between
status snapshots. The following example causes the clustat utility to display cluster status every 10
seconds:
