RQDs only pick up to a maximum of 12 frames in a job regardless of number of RQDs

[simonlvr]

Describe the bug We deploy Opencue on Google Cloud and regularly spin up instances to handle large jobs of thousands of frames, but can't achieve more than 12 hosts per job.

To Reproduce Steps to reproduce the behavior:

1. We start cuebot
2. We spin up x30 rqds via an instance group on Google Cloud
3. We wait until they appear as hosts on cuesubmit
4. We submit a job via Cuesubmit, say 1-1000 frames, shell, with limits set as "none"
5. Job picked up by cuebot and displays correctly on Cuegui
6. Only a maximum of 12 rqd pick up the job, leaving the other 18 idle
7. When we split the job into two, a maximum of 12 rqds pick up the job.
8. Have checked all documentation, tried setting different max limits (i.e. max 30), and always the same result.
9. There are no labels or dependencies in play.

Expected behavior Expect to launch 30 instances, submit 1 job and for all 30 instances to pick up the job.

Version Number Opencue installed via: git clone -b 0.3.43 https://github.com/AcademySoftwareFoundation/OpenCue.git Python venv 3.7.0 Using 2>3

[DiegoTavares]

Sorry for the long delay on responding.

From the surface, this looks to be a configuration problem. Can you try changing dispatcher.host_frame_dispatch_max=12 to 20 and checking if the behaviour changes? If not, I can make a deeper investigation.

https://github.com/AcademySoftwareFoundation/OpenCue/blob/master/cuebot/src/main/resources/opencue.properties