Design – Build – Run: Applied Practices and Principles for Production-Ready Software Development

10.2. The Batch Scheduler

The batch scheduler is the application that executes batch schedules and jobs. Most batch schedulers support multiple operating systems and platforms. Batch schedulers, also known as job schedulers, support the following high-level functions:

• Defining batch jobs and batch schedules

• Defining batch calendars

• Defining batch nodes and node groups (servers)

• Executing and controlling batch schedules and batch jobs

• Monitoring schedules and job execution (including alerts and re-submission)

• Recycling batch schedules for the next run date

The batch scheduler is normally installed on a dedicated server, whereas agents are installed on individual servers that execute batch processes. This follows the master-agent architecture previously discussed.

Most schedulers show a diagram view of the batch schedule, using a colored, "traffic light" system:

• Red typically indicates a job has failed.

• Green means the job has completed successfully.

• Amber means the job is running or executing.

• Blue or some other color is often used to indicate a communication error with a node or server to distinguish the failure.

Jobs waiting for scheduling typically are not colored. Figure 10-2 shows a mockup of the batch scheduler execution display where all jobs are essentially waiting to be scheduled, as they are not colored. As the schedule starts executing, the jobs would be colored according to their state.

Figure 10.2. Figure 10-2

In the early days of testing and deployment for batch, this ...