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
|
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:
