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.