Designing a Continental Cluster
Designing a Disaster Tolerant Architecture for use with ContinentalClusters
Chapter 254
Designing a Disaster Tolerant Architecture
for use with ContinentalClusters
A recovery pair in a continental cluster consists of two Serviceguard
clusters. One functions as a primary cluster and the other functions as
recovery cluster for a specific application. Prior to Continentalclusters
version A.05.00, one recovery pair can be configured in a continental
cluster. Starting with Continentalclusters version A.05.00, a
configuration of multiple recovery pairs is allowed.
In the multiple recovery pair configuration, more than one primary
cluster (where the primary packages are running) can be configured to
share the same recovery cluster (where the recovery package is running).
The key elements providing disaster tolerance in a continental cluster
recovery pair are:
• Mutual Recovery
• Serviceguard clusters
• Data replication
• Highly available WAN networking
• Data center processes and procedures coordinated between the two
cluster sites
There is significant amount of latitude in selecting these elements for a
configuration. It is recommended the choices are recorded on worksheets
which can be reviewed and updated periodically.
Mutual Recovery
For mutual recovery, any cluster in a continental cluster recovery pair
may contain both primary and recovery packages for any recovery group.
Recovery groups may be defined, for example, such that cluster A and
cluster B contain recovery packages. In this case, cmrecovercl could be
run on cluster B to recover packages from cluster A, or on cluster A to
recover packages from cluster B.