GrowthBook maxConcurrentQueries not respected queries bypass the queue BigQuery

TL;DR

Upgrade GrowthBook to a version containing that fix. With maxConcurrentQueries: 2 set on a BigQuery data source, GrowthBook starts 2 queries but as soon as one finishes it runs all remaining queries at once, with 6 metrics, 4 extra queries launch together.

Steps

1. With maxConcurrentQueries: 2 set on a BigQuery data source, GrowthBook starts 2 queries but as soon as one finishes it runs all remaining queries at once, with 6 metrics, 4 extra queries launch together. The concurrency setting is not being honored, overloading the warehouse.
2. This was a GrowthBook bug in the query queue that a maintainer fixed in a PR; the reporter tested it for several days and confirmed it solved the issue. Upgrade GrowthBook to a version containing that fix. The fix makes the queue hold back the remaining queries instead of releasing them all when one slot frees up.
3. Take the question above and check if it matches what you're seeing. If it does, work through the verified fix step by step. Start with the cause described first, because that's what tells you the fix applies to your setup, then apply the changes in the order given. Verify by re-running whatever failed before, and expect the same behavior the thread author reported.

When to use

You are seeing this: The concurrency setting is not being honored, overloading the warehouse. Use this skill when you run into "GrowthBook maxConcurrentQueries not respected queries bypass the queue BigQuery".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Someone asked: With maxConcurrentQueries: 2 set on a BigQuery data source, GrowthBook starts 2 queries but as soon as one finishes it runs all remaining queries at once, with 6 metrics, 4 extra queries launch together. The concurrency setting is not being honored, overloading the warehouse. The verified answer: This was a GrowthBook bug in the query queue that a maintainer fixed in a PR; the reporter tested it for several days and confirmed it solved the issue. Upgrade GrowthBook to a version containing that fix. The fix makes the queue hold back the remaining queries instead of releasing them all when one slot frees up.

Source: https://github.com/growthbook/growthbook/issues/3291 Discussion and confirmation live at https://vectle.com/threads/thr_xe35Th743tnahmu3MRRv3w