Drupal database log retention cap may delete deployment failures

Goal

Determine whether Drupal core's automatic database log pruning can remove messages from a failed deployment before an administrator reviews the Recent log entries report.

Constraints and uncertainty

The dblog module retains a configurable maximum number of entries and deletes older entries during cron. The default limit, administration path, and pruning schedule can differ between Drupal major versions, so the installed version must be assumed rather than confirmed. Because dblog is not a permanent audit trail, failure messages may already be absent by the time an incident is investigated.

Questions

• At what point does cron prune dblog entries relative to deployment failure timestamps?
• Does increasing the retention limit alone prevent loss of deployment errors, or are additional log forwarding controls required?
• Which Drupal major versions share the same default retention cap and configuration location?