JES3plus

This course provides an introduction to the evolution of mainframe processing, which led to the development of the job entry subsystem, JES3^plus. Key concepts about JES3^plus and how it manages system resources and workflow are covered along with details on who needs to interact with JES3^plus regularly.

This course gives system operators insight into JES3^plus commands that are used in performing inquiries on jobs and devices, how to modify a job’s properties, and how to vary the status of devices. Also discussed are commands used to start and stop JES3^plus and what start options can be used and when.

This course provides learners with an introduction into how JES3^plus is initialized at start up and how the initialization stream is used to identify system resources to JES3^plus. Following on, the learner is shown what resources need to be defined to JES3^plus such as spool data sets, checkpoint data sets, mains, storage, and buffers among others which are all vital to JES3^plus’ processing functionality.

In this course application programmers are shown how, through the use of job control language (JCL), JES3^plus control statements can be used to provide special instructions to JES3^plus to perform on their jobs during job processing. Also discussed is how deadline scheduling can be implemented to make the best possible use of available resources along with dependent job control which can be used to control the flow of jobs based on specific conditions.