On September 12, 2025, between 01:42 AM and 03:09 AM PDT, some PlayFab customers experienced issues authenticating with Photon APIs. The incident was caused by unexpected traffic patterns to Photon API endpoints, which resulted in a hot partition and degraded availability. We resolved the issue by setting a throttle limit for the affected API endpoint.

Impact

During the incident, customers with Photon tokens stored on the hot partition may have been unable to authenticate. The availability for Photon APIs dropped to as low as 78.8%, impacting service reliability for approximately 1 hour and 27 minutes.

Root Cause Analysis

The root cause was an unexpected traffic pattern on the Photon authentication API endpoint. A large call volume on this endpoint put strain on database lookup tables for logging in the user. The call volume was outside normal parameters.

Action Items

To prevent similar incidents from happening again, we have taken the following actions:

·       Cached results from previous Photon sessions to reduce strain on the database infrastructure.

·       Adjusted the title rate limit for the Photon APIs.