Use this task to configure a backup cluster that handles Enterprise JavaBeans (EJB) requests if
the primary cluster fails.
Before you begin
Deprecated feature: Backup clusters are deprecated in
WebSphere® Application Server Version 9. Instead of using IIOP based Backup
Clusters across multiple Cells using CoreGroupBridges, you should consider wrapping EJB capabilities
with
REST interfaces. Then use front-end
load balancing, such as On Demand Router, to balance the load.
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.
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Connect the administrative console for the deployment manager that contains the backup
cluster.
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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.
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Connect the administrative console to the deployment manager that contains the primary cluster.
Click cluster_name > Backup cluster.
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Ensure that the name of the backup cluster is the same as the primary cluster.
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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.
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Click OK.
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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.
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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.