NetBatch Manual

NetBatch Introduction
NetBatch Manual—522460-004
1-6
Scheduler Functions
Scheduler Functions
The scheduler is a process-pair server whose functions are to:
•
Store job records in its database
•
Schedule and start jobs
•
Track and control job execution
•
Record job termination details
This subsection expands this definition after describing how the scheduler assigns and
controls the flow of jobs to CPUs.
CPU Assignment
The scheduler assigns jobs to CPUs by means of its classes and executors. By
manipulating these classes and executors, you can control the flow of jobs to the
CPUs.
Classes
A class is a logical entity in the scheduler. Its purpose is to group jobs and to control
their flow to executors and thereby to the executors’ CPUs.
•
The CLASS job attribute assigns a job to a class.
•
The INITIATION class attribute controls job flow from the class to executors.
When set to ON, the attribute enables the scheduler to select jobs from the
class. When set to OFF, the attribute prevents the scheduler from scanning
the class and so prevents the class’s jobs from running.
Classes are the job queuing mechanisms of the scheduler. You can assign a class to
multiple executors to give its jobs opportunities to execute in different CPUs.
To add classes to the scheduler and display, and to alter their attributes, use the
BATCHCOM commands ADD CLASS, INFO CLASS, and ALTER CLASS. To delete
classes, use the BATCHCOM command DELETE CLASS.
Executors
Like a class, an executor is a logical entity in the scheduler. Its purpose is to link jobs
by way of their classes to a CPU. This link enables the scheduler to start, in the
specified CPU, the initial process (the executor program) of each job.
•
The CLASS executor attribute specifies the executor’s classes.
•
The CPU executor attribute specifies the executor’s CPU.
Executors act as gateways between classes and CPUs. When started, an executor lets
one job at a time from the classes run in its CPU. No other jobs can use the executor