Dell PowerConnect W Clearpass 100 Software 3.9 Deployment Guide - Page 439

Cluster Troubleshooting, Restart Cluster Services, View Log Files

Page 439 highlights

Immediately after the cluster is destroyed, both nodes will have the same database and configuration state. However, changes on one node will no longer be replicated to the other node as the cluster is no longer functioning. Cluster Troubleshooting When building a cluster, use the recommended values for the downtime threshold, keep-alive rate and configuration sync rate. You should only change these values if you have a specific requirement and have verified that different values can be used to meet that requirement. To avoid unexpected failover of the cluster, ensure that the network connection to the nodes of the cluster is always available. Use high quality network equipment, including cables, and secure physical access to the servers to prevent accidental dislodgement of cables. If network access to the cluster is intermittent, this may indicate a possible hardware failure on the current primary node. In this situation, you may either use the Swap Primary Server command to make the secondary node the new primary node, or you can cause the cluster to failover to the secondary by disconnecting the primary node. Brief network outages are permissible and will not cause failover, provided that the network outage is shorter than the downtime threshold of the cluster. During a failover from the primary to the secondary node, the network services provided by the cluster will be unavailable. The time that the cluster will be offline is bounded by the downtime threshold. This can be used to calculate the expected availability of the cluster. The Restart Cluster Services and Stop Cluster Services command links on the Cluster Maintenance page may be used to test failover conditions by simulating a cluster failure. Avoid using these commands when you are accessing the cluster using its virtual IP address, as the virtual IP address may become unavailable. The View Log Files command link allows the internal state of the cluster to be viewed. This may be useful if debugging a problem related to the cluster. The log files may be exported to a zip file. If you require support about a cluster-related problem, include a copy of the exported cluster log files with your support request. ClearPass Guest 3.9 | Deployment Guide High Availability Services | 439

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ClearPass Guest 3.9
|
Deployment Guide
High Availability Services
|
439
Immediately after the cluster is destroyed, both nodes will have the same database and configuration state.
However, changes on one node will no longer be replicated to the other node as the cluster is no longer
functioning.
Cluster Troubleshooting
When building a cluster, use the recommended values for the downtime threshold, keep-alive rate and
configuration sync rate. You should only change these values if you have a specific requirement and have
verified that different values can be used to meet that requirement.
To avoid unexpected failover of the cluster, ensure that the network connection to the nodes of the cluster
is always available. Use high quality network equipment, including cables, and secure physical access to the
servers to prevent accidental dislodgement of cables.
If network access to the cluster is intermittent, this may indicate a possible hardware failure on the current
primary node. In this situation, you may either use the Swap Primary Server command to make the
secondary node the new primary node, or you can cause the cluster to failover to the secondary by
disconnecting the primary node.
Brief network outages are permissible and will not cause failover, provided that the network outage is
shorter than the downtime threshold of the cluster.
During a failover from the primary to the secondary node, the network services provided by the cluster will
be unavailable. The time that the cluster will be offline is bounded by the downtime threshold. This can be
used to calculate the expected availability of the cluster.
The
Restart Cluster Services
and
Stop Cluster Services
command links on the Cluster Maintenance
page may be used to test failover conditions by simulating a cluster failure.
The
View Log Files
command link allows the internal state of the cluster to be viewed.
This may be useful if debugging a problem related to the cluster. The log files may be exported to a zip file.
If you require support about a cluster-related problem, include a copy of the exported cluster log files with
your support request.
Avoid using these commands when you are accessing the cluster using its virtual IP address, as the virtual IP
address may become unavailable.