Creating a clustered environment enhances the failover and scaling
characteristics of WebSphere Process Server applications.
To establish a clustered environment, you and your team will perform the described
steps.
Before you begin
There are a number of things you should do before creating a clustered
environment:
- Ensure that you have adequate resources to implement clustering successfully.
- Analyze the service applications you will deploy into the clustered environment.
Some of the optional steps you perform depend on the needs of the service
applications.
- Ensure that the application logic is tolerant of a clustered environment,
for example:
- The application tolerates partitioned queues when you make provisions
for orphaned requests or for requests processed out of order. An application
failure may create one or both of these situations.
- There are no system-wide values that you maintain locally.
- Familiarize yourself with network deployment and clustering as described
in the WebSphere® Application Server Network Deployment,
version 6 information
center.
- Familiarize yourself with these instructions before performing any of
the steps. An overall idea of the steps can help you proceed efficiently.
- Create a cell:
- Install the WebSphere Process Server software
on the hardware that will be included in the environment.
- Create the database (or databases) and database schemas
needed by the components of the cell:
- The database to contain the WebSphere Process Server repository.
- Optional: The database (or schema) used for logging Enterprise Service Bus (ESB)
mediation events.
- Create the deployment manager and managed profiles.
- Federate profiles to the deployment manager.
Note: You must federate the
profiles sequentially.
Important: You cannot federate stand
alone WebSphere Process Server profiles.
Why and when to perform this task
Create a clustered environment when your application requires
more capacity and availability than a single server provides. The clustered
environment provides these additional benefits:
- Workload balancing
- By running application images on multiple servers, a cluster balances
an application workload across the servers in the cluster.
- Processing power for the application
- You can add processing power to your application by configuring additional
server hardware as cluster members supporting the application.
- Application availability
- When a server fails the application continues to process work on the other
servers in the cluster thereby allowing recovery efforts to proceed without
impacting application users.
- Maintainability
- You can stop a server for planned maintenance without stopping application
processing.
- Flexibility
- You can add or remove capacity as needed by using the administrative console.
Note: A list of related tasks is included at the bottom
of this page. The title of any related tasks for a particular step is contained
as a parenthetical comment for that step. If you are unfamiliar with the task,
see the related topic for additional information.
Steps for this task
- Design the cell.
- Lay out the topology of the cell. Determine what physical and
logical resources are needed for the cell.
- Decide whether to use databases or schemas
for the various components of the cell.
- Decide if there is a need for monitored events and which servers
should host the monitored events.
- Create other databases needed by the cell, such
as:
- The database (and schemas) to be used by
the messaging engines of WebSphere Platform Messaging when you use the default
messaging provider.
- Optional: The databases (or schema)
to be used as the Business Process Execution Language (BPEL) repositories.
(Configuring Business Process Choreographer)
- Optional: The database (or schema)
to be used for the event database. (Configuring the Common Event Infrastructure)
- Optional: Create the cluster that
handles monitored events, if you need monitored events.
- Create the cluster with cluster members using the default WebSphere Process Server template.
- Using the cluster you are configuring as the target and the Common Event Infrastructure (CEI) database created
in step 2.c, install
the CEI application, and install the message-driven bean (MDB) application.
(Configuring the Common Event Infrastructure)
- Optional: Create the cluster that
handles administration applications, if the application contains business
rules or selectors and the application requires modification to the rules
or selectors after you deploy the application.
Note: If you have
determined that administration of business rules and selectors will be deployed
to clusters that handle other
WebSphere Process Server components,
you can combine this step with either step
3 or
step
6.
- Create the cluster with cluster members using the default WebSphere Process Server Template.
- Use the Advanced Configuration panel to deploy the business
rules manager server.
- Configure messaging for the cluster.
Note: If
you have determined that administration messaging will be handled by clusters
that handle other
WebSphere Process Server components,
you can combine this step with either step
3,
step
4, or step
6.
Important: This
step must be completed before installing the first service application in
the cluster.
- Create the cluster using the default WebSphere Process Server template.
- Select Default Destination Location on
the Advanced Configuration panel.
- Add the cluster as a member of the Event bus.
Use
the data source you created in step 2.c. If in step 1.b you
decided to use multiple schemas in a single database, select the correct schema
when configuring the messaging engine data source.
- Add the cluster as a bus member of the Business Process Choreographer
bus.
Use the data source you created in step 2.b. If in step1.b
you decided to use multiple schemas in a single database, select the correct
schema when configuring the messaging engine data source.
- Create the cluster for service applications.
- Create the cluster with cluster members using the default WebSphere Process Server template
- Use the Advanced Configuration panel to select the messaging
cluster.
When combining this step with step 5,
select the default messaging cluster as stated in that step. Otherwise, select
the correct option and choose the cluster you created in 5.
- Optional: Configure Business Process Choreographer
support using the databases or schemas created in step 2.b. (Configuring Business Process Choreographer)
Perform this step when an application contains Business Process Execution
Language (BPEL) or business state machine components.
- Optional: Use the Advanced Configuration panel to
select the Java Naming and Directory Interface (JNDI) name of the emitter
factory profile to associate the cluster with the emitter factory profile
you created in step 2.c.
Result
When you start the servers and any installed applications, they will
start normally.
What to do next
You can now install applications on the cluster.
Last updated: Wed 06 Dec 2006 07:08:08
(c) Copyright IBM Corporation 2005, 2006.
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