On March 3, 2025, we experienced a temporary service slowdown impacting the availability of session information in the US-East-1 region. The issue began at 13:19 UTC and was resolved by 15:15 UTC. The Data API and Reports API experienced delays and intermittent failures when returning session results. Authoring and Assessment APIs were unaffected with no data loss.
We identified a recently introduced inefficient database query was causing unnecessary strain when handling extremely large data sets. This led to delayed responses to the Data API sessions endpoints. This further led to delays or unavailability in select reports via the Reports API. Additionally, some timeouts and safeguards that should have triggered earlier did not activate as expected.
To quickly restore performance:
Following these fixes, all services resumed normal operations.
To prevent future occurrences:
We appreciate your patience and remain committed to delivering a seamless experience.