Job slicing does not respect host limit, leading to unnecessary job failures

jangel97 commented 1 month ago

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Bug Summary

I have a job template that runs against approximately 50 hosts. To speed up execution, I've set Job Slicing to 5, which effectively runs 5 parallel jobs against 10 hosts each.

However, when I run this job template with a limit set to target only 2 hosts, the job still creates 5 slices. As a result:

1 slice succeeds (processing the 2 limited hosts).
4 slices fail because they have no hosts to run against.

This behavior causes the overall job to report failures, and since I have alerting configured, I receive unnecessary failure notifications.

My deployment of AAP is in VMs.

AWX version

AAP 2.4

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Installation method

N/A

Modifications

no

Ansible version

No response

Operating system

RHEL 8

Web browser

No response

Steps to reproduce

Create a job template with Job Slicing set to 5.
Set a limit to target a small number of hosts (e.g., 2 hosts).
Launch the job template.
Observe that multiple slices fail due to having no hosts assigned.

Expected results

When a limit is set that results in fewer hosts than the number of slices, AWX should adjust the number of slices accordingly. In this case, it should:

Create only 1 slice to handle the 2 hosts.
Avoid creating additional slices that have no hosts to process.

Actual results

AWX creates the maximum number of slices specified (5 in this case), regardless of the number of hosts after applying the limit.
Slices without any hosts assigned fail, impacting the overall job status.

Additional information

Perhaps this is fixed in AAP 2.5?

jangel97 commented 1 month ago

I am willing to discuss about implementation details and create PR for this, if it makes sense to fix this

jangel97 commented 2 weeks ago

@fosterseth @shanemcd does this make sense to you? Thx!

ansible / awx