Job Execution Delays Caused by Queue Slot Limitations

Products

• Automic SaaS
• CA Automic Workload Automation - Automation Engine
• CA Automic One Automation

Issue/Introduction

Workflows may experience significant, consistent delays (e.g., 15–20 minutes) between the completion of one task and the start of the next.

• The Automation Engine (AE) logs appear normal with no performance errors.
• The Agent logs show no errors and confirm other jobs are running successfully.
• No changes were made to the workflow or job configurations.
• The job experiencing the delay within the workflow has a queue assigned to it that has a defined number of Maximum Slots

Environment

This can happen on any version or system type as Queues are a standard object type.

Cause

The delay is caused by the job reaching the Max. Slots limit of its assigned Queue object.

When a job is ready to start but the assigned Queue has no available slots, the job enters a transient "Waiting for Queue Slot" status. This is a standard load-balancing behavior rather than a system error, and is not captured in final job reports or historical logs once the job completes.

Resolution

To identify and resolve delays related to Queue saturation, follow these steps:

1. Identify the Queue Assignment

• Open the affected Job (JOBS) object.
• Navigate to the Attributes tab.
• Identify the name of the object in the Queue field (Default is often CLIENT_QUEUE).
• Note: Information on Queues can be found in the Queue (QUEUE) documentaiton page.

2. Analyze Queue Capacity

• Open the Queue object definition found in the identified Queue field.
• Check the Max. Slots value. If this is set to a low number, it limits how many jobs can run concurrently in that queue.

3. Verify Concurrent Execution

• Use the Process Monitoring perspective to look at the time of the delay.
• Check if other high-volume or long-running jobs were occupying all available slots in that specific Queue during the 15-minute gap.

4. Remediation

• Increase Slots: If the infrastructure can handle the load, increase the Max. Slots in the Queue object definition.
• Redistribute Jobs: Move non-critical or high-volume jobs to a different Queue object to prevent bottlenecking critical workflows.
• Adjust Priorities: Ensure critical workflows have a higher Priority (1-255) within the Queue to jump ahead of other waiting tasks when a slot becomes available.

Note: Information on monitoring queues in real-time in the Process Monitoring perspective can be found on the Monitoring Tasks Quick Filter documentation page

Additional Information

Standard job reports usually show the start and end time of the execution on the Agent but may not capture the full duration the job spent in a "Waiting" status on the Engine side due to Queue limits. Always verify Queue throughput when execution gaps occur.