Chapter 6. WebSphere Batch 157
Figure 6-10 describes the parallel batch functions and shows the batch flow from the job
scheduler to the batch container endpoints.
Figure 6-10 Parallel batch functional diagram
6.5.2 Enterprise integration
Many customers already use an external workload scheduler to manage batch workloads.
Although a Java batch that runs inside a WebSphere Application Server environment is
attractive, controlling batch jobs through an external workload scheduler is important.
You can integrate the job scheduler with an external workload scheduler by configuring and
securing the job scheduler, enabling the interface, and running batch jobs.
You can set up the external scheduler interface by using the default messaging provider as a
JMS provider. In z/OS, you also have the option of setting up the external scheduler interface
by using WebSphere MQ as a messaging provider.
Because an external scheduler does not know how to directly manage batch jobs, a proxy
model is used. The proxy model uses a regular job control language (JCL) job to submit,
monitor, or submit and monitor the batch job. The JCL job step starts a special program
provided by batch called WSGRID. The WSGRID application submits and monitors a
specified batch job. WSGRID writes intermediary results of the job into the JCL job log.
WebSphere Application Server
Java virtual machine
Batch
scheduler
WebSphere Application Server
Foundation Services level
(security, transaction, data access, logging, and so forth)
Batch
WebSphere Application Server v 8.5 Cell
WebSphere Application Server
Java virtual machine
BATCH container
IBM batch
container
classes and APIs
Batch
Controller
Batch
application
WebSphere Application Server
Java virtual machine
BATCH container
IBM batch
container
classes and APIs
Batch
Controller
Batch
application
WebSphere Application Server
Java virtual machine
BATCH container
IBM batch
container
classes and APIs
Batch
Controller
Batch
application
158 WebSphere Application Server V8.5 Concepts, Planning, and Design Guide
WSGRID does not return until the underlying job is complete, providing a synchronous
execution model.
Because the external scheduler can manage JCL jobs, it can manage a JCL job that started
WSGRID. Using this pattern, the external scheduler can indirectly manage a job. An optional
plug-in interface in the job scheduler enables a user to add code that updates the external
scheduler operation plan. This update reflects the unique state of the underlying job, such as
job started, step started, step ended, or job ended. The WSGRID program is written with
special recovery processing. If the JCL job is canceled, the underlying job is canceled also,
ensuring that the lifecycles of the two jobs are synchronized.
Enterprise integration includes the following key features:
WebSphere Application Server V8.5 includes a special “connector” for Tivoli Workload
Scheduler and competing workload schedulers.
Tivoli Workload Scheduler and WebSphere Batch provide a common deployment pattern.
WebSphere Batch allows full control of the enterprise workload scheduler.
Figure 6-11 shows the workload coming from Tivoli Workload Scheduler directly to the job
scheduler, using a workload connector.
Figure 6-11 Enterprise integration functional diagram
Java virtual machine
WebSphere Application Server
WebSphere Application Server
Foundation Services level
(security, transaction, data access, logging, and so forth)
WebSphere Application Server
Java virtual machine
BATCH container
IBM batch
container
classes and APIs
Batch
Controller
Batch
application
WebSphere Application Server
Java virtual machine
BATCH container
IBM batch
container
classes and APIs
Batch
Controller
WebSphere Application Server
Java virtual machine
BATCH container
IBM batch
container
classes and APIs
Batch
Controller
Tivoli
Workload
Scheduler
Batch
Workload
connector
Other
workload
WebSphere Application Server v 8.5 Cell
Batch
application
Batch
application
Batch
scheduler
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