Degraded-performance in MLS Observer thruough DU - US

Final update

## Customer impact Between approximately 3:20 pm UTC and 3:40 pm UTC on September 3, 2026, some customers using Document Understanding in the US experienced failed document processing requests. Affected requests returned service unavailable errors, and some extraction and processing calls did not complete successfully. The impact lasted approximately 20 minutes and was limited to Document Understanding in the US region. ## Root cause A scheduled backend deployment supporting Document Understanding triggered a rolling update of service instances in the US region. During this process, replacement instances could not start promptly because the required compute resources were temporarily occupied by other workloads. Because the affected service was already handling heavy traffic, the temporary reduction in available instances caused some requests to be rejected with service unavailable errors. ## Detection An automated failed-requests alert detected the issue at 3:19 pm UTC on September 3, 2026. The alert was escalated immediately, and the incident was declared customer-impacting at 3:20 pm UTC. Detection occurred within approximately one minute of the start of customer impact. ## Resp

1. Postmortem · Sep 25, 11:11 UTC
   ## Customer impact Between approximately 3:20 pm UTC and 3:40 pm UTC on September 3, 2026, some customers using Document Understanding in the US experienced failed document processing requests. Affected requests returned service unavailable errors, and some extraction and processing calls did not complete successfully. The impact lasted approximately 20 minutes and was limited to Document Understanding in the US region. ## Root cause A scheduled backend deployment supporting Document Understanding triggered a rolling update of service instances in the US region. During this process, replacement instances could not start promptly because the required compute resources were temporarily occupied by other workloads. Because the affected service was already handling heavy traffic, the temporary reduction in available instances caused some requests to be rejected with service unavailable errors. ## Detection An automated failed-requests alert detected the issue at 3:19 pm UTC on September 3, 2026. The alert was escalated immediately, and the incident was declared customer-impacting at 3:20 pm UTC. Detection occurred within approximately one minute of the start of customer impact. ## Response By 3:22 pm UTC, responders joined the incident response call and began coordinating mitigation. At 3:34 pm UTC, a public status update confirmed that investigation was in progress. By 3:39 pm UTC, the cause had been identified and mitigation steps were underway. To restore service, the team pau
2. Resolved · Sep 3, 16:17 UTC
   The issue has been successfully resolved, and the service has been fully restored. The service is operating normally at this time.
3. Monitoring · Sep 3, 15:47 UTC
   The issue has been successfully resolved, and the service has been fully restored. The service is operating normally at this time.
4. Identified · Sep 3, 15:39 UTC
   The issue was identified, and the appropriate mitigation measures were implemented to address it.
5. Investigating · Sep 3, 15:34 UTC
   We are currently investigaing the issue