Is FatTail down?

We are aware of and urgently investigating an issue with AdBook system performance. Users may encounter intermittent errors trafficking lines, checking availability, and running reports. Further updates will be provided here as soon as they are available. Thank you for your patience while we work to restore performance. Please contact us at support.fattail.com with questions.

Our engineering team has identified the issue impacting system performance and completed system optimizations. Performance remains stable at this time. We will leave this incident open for monitoring. Please reach out via support.fattail.com if you have questions or concerns.

This incident has been resolved.

### **Summary of Impact** On the afternoon of June 22, 2026, users of [adbook03.fattail.com](http://adbook02.fattail.com/) and [adbook04.fattail.com](http://adbook04.fattail.com) experienced trafficking errors and slow response time on campaign uploads and reporting. Performance degradation was first observed and reported at approx. 4:30pm EST. The FatTail engineering team was able to resolve and restore services at approximately 6:25pm EST. ### **Root Cause** The degradation was caused by elevated request volume that put high pressure on the service caching mechanisms, which caused a slowdown in response time. **Mitigation** There were two steps taken to mitigate the issue: 1. The reporting services were restarted to clear out orphaned \(timed out\) requests that were queued up in the caching service. 2. Cache parameters were updated to provide more resources to handle elevated request volume.  ### **Next Steps** The team is implementing monitoring to raise alerts when cache resources are out of normal operating zones.