# Mixpanel: Degraded Query API Performance impacting US Projects

- Provider: [Mixpanel](https://outages.cc/mixpanel.md)
- Type: Incident
- State: Resolved
- Worst impact: Partial outage
- Started: 2026-08-26 21:39 UTC
- Resolved: 2026-08-26 22:45 UTC (lasted 1 h 7 min)
- Components: Application Availability (US)
- Official update: https://stspg.io/p7k1qngjlzn1

## Updates from Mixpanel

### postmortem, 2026-09-08 18:25 UTC

# Mixpanel RCA: Temporary Query Service Disruption for US Projects August 26, 2026 # Summary Between approximately **2:02 PM and 3:19 PM PT on August 26, 2026**, projects in the US region experienced failures loading reports and running queries through the Mixpanel UI and Query API. During this window, some queries in the region failed or returned errors. **No customer data was lost, and data ingestion was not affected.** All events continued to be collected and stored normally throughout the incident; once query service was restored, all reports reflected complete, accurate data with no customer action required. The cause was identified as a recently deployed internal tool for diagnostic query replay, a capability our engineers use to re-run copies of past queries to debug performance, which unexpectedly wrote large amounts of data to the disks of our query servers, consuming storage capacity the servers need to operate. When those disks filled, the affected servers took themselves ou

### resolved, 2026-08-26 22:45 UTC

This incident has been resolved.

### monitoring, 2026-08-26 22:28 UTC

A fix has been implemented, and we're seeing improved success rates for the Query API. We will continue monitoring to ensure stability.

### identified, 2026-08-26 22:11 UTC

The issue has been identified and a fix is being implemented.

### investigating, 2026-08-26 21:39 UTC

Mixpanel is experiencing degraded Query API performance, resulting in HTTP 500 responses when querying reports for projects with US Data Residency. Projects with EU and IN Data Residency remain unaffected. We appreciate your patience while our engineers work to restore normal functionality. We will post progress updates on our status page. If you have any questions, please contact support.