Designing a Continental Cluster
Designing a Disaster Tolerant Architecture for use with ContinentalClusters
Chapter 260
Highly Available Wide Area Networking
Disaster tolerant networking for Continentalclusters is directly tied to
the data replication method. In addition to the reliability of the
redundant lines connecting the remote nodes, it is important to consider
what bandwidth is needed to support the data replication method that
has been chosen.
A continental cluster that handles a high number of write transactions
per minute will not only require a highly available network, but also one
with a large amount of bandwidth. Details on highly available
networking can be found in Chapter 1, in the section titled “Disaster
Tolerant Architecture Guidelines.” White papers describing specific
implementations are also available at: www.docs.hp.com -> High
Availability -> Continentalcluster or Metrocluster -> White Papers
Data Center Processes
ContinentalClusters provides the cmrecovercl command that fails over
all applications on the primary cluster in a recovery pair that are
protected by ContinentalClusters. However, application failover also
requires well-defined processes for the two sites of a recovery pair. These
processes and procedures should be written down and made available at
both sites.
Some considerations for site management are as follows:
• Who notifies whom for the various events: configuration changes,
alerts, alarms?
• What communication methods should be used? Email? Phone?
Beeper? Multiple methods?
• Who has the authority to perform what sort of configuration
modifications? Can the administrator at one site log in to the nodes
on the remote site? If so, what permissions would be set?
• How often is a practice failover done?
• Is there a documented test plan?
• What is the process for tracking changes made to the primary
cluster?