fewest-build-containers: tasks in aggregate land on the same worker #3301
Description
Bug Report
The "fewest-build-container" placement strategy always puts tasks within an aggregate block to the same worker.
Steps to Reproduce
- enable the fewest-build-container strategy
- create a pipeline with an aggregate block
- name: job with aggregate
plan:
- aggregate:
- task: build-on-ubuntu-16.04
- task: build-on-ubuntu-18.04
Schedule some builds and observe the output of fly containers
Expected Results
Tasks within an aggregate respect the fewest-build-container strategy. Sometimes they may land on the same worker.
Actual Results
Tasks within an aggregate always land on the same worker.
Additional Context
A sample output of fly containers:
63aebe28-b48c-4ac1-6d33-ba1a84300cac wrk-lin-0-07b4efc347e46c064 pipeline-master build 81 84161 task build-ubuntu-18.04 n/a
71e38b7e-aaf0-42db-462e-7d2a361ec90a wrk-lin-0-07b4efc347e46c064 pipeline-master build 81 84161 task build-ubuntu-16.04 n/a
[...]
ddd3b498-b3f8-44ce-4735-246937b4b884 wrk-lin-3-0544d8e8cdbc32852 pipeline-master conan-pkg 15 84179 task build-ubuntu-16.04 n/a
e720603b-537c-4c49-4be1-cdeb37402155 wrk-lin-3-0544d8e8cdbc32852 pipeline-master conan-pkg 15 84179 task build-ubuntu-18.04 n/a
Version Info
- Concourse version: 5.0 RC 74
- Deployment type (BOSH/Docker/binary): binary
- Infrastructure/IaaS: AWS
- Browser (if applicable):
- Did this used to work? no.