Feature Request / Improvement

We've been having a lot of issues with merging lately. This is mostly due to a lack of runners. Here's some ideas that I've had to help stabilize our CI issues:

Throughput + cost

• Build queue entries in parallel (CI: Reduce workflow overhead #3962)
• use ubuntu-slim for lightweight jobs (CI: Reduce workflow overhead #3962, CI: Cancel stale merge queue runs + use ubuntu-slim #4106 )
• cancel superseded PR runs with concurrency (CI: Reduce workflow overhead #3962, CI: Cancel stale merge queue runs + use ubuntu-slim #4106)
• Consider running integration tests only in merge queue (we need to stabilize the merge queue a lot before we consider this)
• Combine smaller checks into a single workflow to conserve runners

Flaky Tests

• Run markdown-link-check only at release time. We've been seeing more + more 500s being thrown by external links and

Emergency Bypass

iceberg-rust is introducing a system to allow maintainers to bypass the merge queue. Here's the list of steps they took.

• Move required_status_checks into the Merge Queue ruleset with strict_required_status_checks_policy: false (iceberg-rust#3459 (ci: move required status checks into the Merge Queue ruleset iceberg-rust#3459))
• Add apache/iceberg-public as a bypass actor for pull requests, and document the process in the contributing guide (iceberg-rust#3458 (ci: let committers bypass the Merge Queue ruleset for urgent fixes iceberg-rust#3458))
• Replace classic branch protection with Infra's "Default Branch Protection" ruleset. Without this, classic protection still blocks the bypass (iceberg-rust#3481 (ci: replace classic branch protection with a ruleset so the bypass works iceberg-rust#3481), still open)