Use this task to configure a backup cluster that handles Enterprise JavaBeans (EJB)
requests if the primary cluster fails.
Before you begin
Before you begin, create two clusters that are able to provide
backup for each other. The objects and resources available in the primary
cluster must also be available in the backup cluster. You must use the same
cluster name, install the same applications, use the same application names,
and define the same resources in the backup cluster as in the primary cluster.
The
primary cluster and the backup cluster must reside in separate cells because
a cluster must have a unique name within a cell.
About this task
Perform this task to create a backup cluster for your EJB clusters.
When all the servers in the primary cluster fail, work is not halted because
the backup cluster can continue serving requests for EJB work.
To configure
a backup cluster, specify a name and a port. The port is called a domain
bootstrap address and consists of a bootstrap host and port. The bootstrap
host is the host that contains the deployment manager in which the backup
cluster is configured. The bootstrap port is equal to the bootstrap port
for the same deployment manager.
The primary cluster and the backup
cluster must reside in separate cells. The bootstrap host and port for the
backup cluster determine which cell contains the backup cluster.
Procedure
- Determine the bootstrap host and port of the backup cluster.
- Connect the administrative console for the deployment manager
that contains the backup cluster.
- Click . The host
and port for the BOOTSTRAP_ADDRESS instance is the host and port that the
backup cluster uses. Remember these values for when you configure the primary
cluster.
- Connect the administrative console to the deployment manager that
contains the primary cluster. Click cluster_name >
Backup cluster.
- Ensure that the name of the backup cluster is the same as the primary
cluster.
- Click Domain bootstrap address. Specify the backup cluster
deployment manager bootstrap host and port in the Host and Port fields.
Click OK. The bootstrap host and port combined define a bootstrap
address for the deployment manager. On the Domain Bootstrap Address
page, use the Configuration tab to statically define the backup cluster;
the static value is consumed each time the deployment manager starts. You
can use the Runtime tab to define the backup cluster during run time
only; when the deployment manager stops, the run-time backup cluster information
is discarded.
- Click OK.
- Configure a core group bridge between each of the cluster core
groups. Use an access point group to join the two core groups.
In the deployment manager for the primary cell, configure an access point
group that has a peer access point that refers to the core group access point
in the backup cell. In the deployment manager for the backup cell, create
an access point group that has the same name as the access point group that
you created in the primary cell. Add a peer access point that refers to the
core group access point in the primary cell. See the topic on configuring
the core group bridge service for more information.
Tip: If
you are configuring a V5.x cluster to back up a cluster that is on the current
release, do not configure the core group bridge service. Core groups are not
supported in V5.x. Therefore, the V5.x cluster does not belong to a core group.
The backup cluster still functions using only the domain bootstrap address.
- Save the configuration.
Results
The backup cluster completes EJB requests when the primary cluster
fails.
What to do next
If you experience problems when configuring
your backup cluster, read the topic on what to do if the workload is not getting
distributed.