A batch application is
a Java™ Platform, Enterprise
Edition (Java EE) application
that conforms to one of the batch programming models. Batch work is
expressed as jobs. Jobs are made up of steps. All steps in a job are
processed sequentially.
All jobs contain the following information:
- The identity of the batch application that performs
the work
- One or more job steps that must be performed to complete the work
- The identity of an artifact within the application that provides
the logic for each job step
- Key and value pairs for each job step to provide additional context
to the application artifacts
Jobs for batch applications contain additional information specific
to the batch programming model:
- Definitions of sources and destinations for data
- Definitions of checkpoint algorithms
- xJCL - job definition
- Jobs are expressed using an XML dialect called XML Job Control
Language (xJCL). This dialect has constructs for expressing all of
the information needed for both compute-intensive and batch jobs,
although some elements of xJCL are only applicable to compute-intensive
or batch jobs. See the xJCL provided with the Sample applications
and the xJCL schema document for more information about xJCL. The
xJCL definition of a job is not part of the batch application. This
definition is constructed separately and submitted to the job scheduler to run.
The job scheduler uses
information in the xJCL to determine where and when the job runs.
- Interfaces used to submit and control jobs
- xJCL jobs can be submitted and controlled through the following
interfaces:
- A command-line interface
- An EJB interface described by the com.ibm.ws.batch.JobScheduler
interface. For more information, see the API documentation for this
interface.
- A Web service interface
- The job management console
- The grid endpoint
- Batch applications run
in a special runtime environment. This runtime environment is provided
by a product-provided Java EE
application, the batch execution environment. This application
is deployed automatically by the system when a batch application
is installed. The application serves as an interface between the job scheduler and batch applications. It provides
the runtime environment for both compute-intensive and transactional
batch applications.