Follow up to T266777: integration instances suffer from high IO latency due to Ceph, one that stands out is the job https://integration.wikimedia.org/ci/job/integration-quibble-fullrun/buildTimeTrend which went from 11 minutes to 22 minutes. It runs the Quibble test runner against mediawiki/core. Notably:

• MediaWiki API tests go from 60 seconds to 110s
• PHPUnit tests that requires a database access go from less than 5 minutes to more than 11 minutes.

Both make heavy use of the MySQL database and that job does not have it under a tmpfs. The database being write heavy, that show up in the stats.

It does not seem to use docker run --tmpfs /workspace/db. That should speed it up.