Final Status: An influx of messages caused some end-point servers to become unresponsive. To remediate impact, engineers restarted the affected servers and confirmed that service had been restored.
User Experience: Affected users may have been unable to receive notifications via the Yammer Desktop Notifier application for Windows.
Customer Impact: Customer impact appears to have been limited.
Incident Start Time: Wednesday, May 20, 2015, at 10:32 PM UTC
Incident End Time: Thursday, May 21, 2015, at 12:50 AM UTC
Preliminary Root Cause: End-point servers were disabled after a large number of messages were being processed simultaneously. The underlying root cause is under investigation.
Next Steps: The following is a list of known action item(s) associated with this incident. As part of the Office 365 problem management process, additional engineering actions may be identified to improve the overall service.
– Action: Identify the underlying root cause and develop a solution to prevent reoccurrences.
Please consider this service notification the final update on the event.