Adding New CI Jobs¶
New CI jobs need to be added following a specific process in order to ensure they don’t block patches unnecessarily and that they aren’t ignored by developers.
We need to have a process for adding CI jobs that is not going to result in a lot of spurious failures due to the new jobs. Bogus CI results force additional rechecks and reduce developer/reviewer confidence in the results.
In addition, maintaining CI jobs is a non-trivial task, and each one we add increases the load on the team. Hopefully having a process that requires the involvement of the new job’s proposer makes it clear that the person/team adding the job has a responsibility to help maintain it. CI is everyone’s problem.
The following steps should be completed in the order listed when adding a new job:
Create an experimental job or hijack an existing job for a single Gerrit change. See the references section for details on how to add a new job. This job should be passing before moving on to the next step.
Verify that the new job is providing a reasonable level of logging. Not too much, not too little. Important logs, such as the OpenStack service logs and basic system logs, are necessary to determine why jobs fail. However, OpenStack Infra has to store the logs from an enormous number of jobs, so it is also important to keep our log artifact sizes under control. When in doubt, try to capture about the same amount of logs as the existing jobs.
Promote the job to check non-voting. While the job should have been passing prior to this, it most likely has not been run a significant number of times, so the overall stability is still unknown.
“Stable” in this case would be defined as not having significantly more spurious failures than the ovb-ha job. Due to the additional complexity of an HA deployment, that job tends to fail for reasons unrelated to the patch being tested more often than the other jobs. We do not want to add any jobs that are less stable. Note that failures due to legitimate problems being caught by the new job should not count against its stability.
Before adding OVB jobs to the check queue, even as non-voting, please check with the CI admins to ensure there is enough OVB capacity to run a large number of new jobs. As of this writing, the OVB cloud capacity is significantly more constrained than regular OpenStack Infra.
A job should remain in this state until it has been proven stable over a period of time. A good rule of thumb would be that after a week of stability the job can and should move to the next step.
Jobs should not remain non-voting indefinitely. This causes reviewers to ignore the results anyway, so the jobs become a waste of resources. Once a job is believed to be stable, it should be made voting as soon as possible.
To assist with confirming the stability of a job, it should be added to the CI Status page at this point. This can actually be done at any time after the job is moved to the check queue, but must be done before the job becomes voting.
Additionally, contact Sagi Shnaidman (sshnaidm on IRC) to get the job added to the Extended CI Status page.
Send an e-mail to openstack-dev, tagged with [tripleo], that explains the purpose of the new job and notifies people that it is about to be made voting.
Make the job voting. At this point there should be sufficient confidence in the job that reviewers can trust the results and should not merge anything which does not pass it.
In addition, be aware that voting multinode jobs are also gating. If the job fails the patch cannot merge. This means a broken job can block all TripleO changes from merging.
Keep an eye on the CI Status page to ensure the job keeps running smoothly. If it starts to fail an unusual amount, please investigate.
Alternatives & History¶
Historically, a number of jobs have been added to the check queue when they were completely broken. This is bad and reduces developer and reviewer confidence in the CI results. It can also block TripleO changes from merging if the broken job is gating.
We also have a bad habit of leaving jobs in the non-voting state, which makes them fairly worthless since reviewers will not respect the results. Per this policy, we should clean up all of the non-voting jobs by either moving them back to experimental, or stabilizing them and making them voting.
This policy would go into effect immediately.
This policy is mostly targeted at new jobs, but we do have a number of non-voting jobs that should be brought into compliance with it.
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