Mixpanel outage history

We’ve received reports that requests to decide.mixpanel.com are failing. Any traffic sent through decide.mixpanel.com may be affected, including feature flags and event tracking. To restore service now, point requests to api.mixpanel.com (US), api-eu.mixpanel.com (EU), or api-in.mixpanel.com (IN) depending on your project's Data Residency. We’re rolling out a mitigation and monitoring the results. We will post progress updates on our status page. If you have any questions, please contact support.

This incident has been resolved.

We've received reports that requests to decide.mixpanel.com are failing. Any traffic sent through decide.mixpanel.com may be affected, including feature flags and event tracking. To restore service now, point requests to api.mixpanel.com (US), api-eu.mixpanel.com (EU), or api-in.mixpanel.com (IN), depending on your project's Data Residency. We've rolled out a mitigation and are monitoring the results. We're seeing traffic restored. We will post progress updates on our status page. If you have any questions, please contact support.

This incident has been resolved.

# **Mixpanel RCA: Requests to** [**decide.mixpanel.com**](http://decide.mixpanel.com) **Failed, October 15–21, 2026** ### **Summary** From Oct 15, 2026 to Oct 21, 2026, requests sent to `decide.mixpanel.com` and `api-decide.mixpanel.com` failed. This affected customers who sent event tracking, profile updates, or feature flag requests to this hostname, usually through a proxy. Events sent to this domain during this window were not received by Mixpanel and this data cannot be restored by Mixpanel. **Traffic sent to** `api.mixpanel.com`**,** `api-js.mixpanel.com,` `api-eu.mixpanel.com`**, and** `api-in.mixpanel.com` **were not affected.** Service on this hostname was unintentionally impacted while we were removing the `/decide` endpoint infrastructure. The hostnames were treated as part of the endpoint due to an incorrect understanding of system dependencies. To prevent this class of issue, we are adding traffic monitoring for the `decide.mixpanel.com` and `api-decide.mixpanel.com` hostnames. We will also require confirmed zero traffic at the hostname level before any hostname is removed. **We have since restored service on** `decide.mixpanel.com` . ### **What happened** Older Mixpanel SDKs called the `/decide` endpoint to fetch configuration for [**Legacy Automatically Tracked Mobile Events**](https://docs.mixpanel.com/docs/tracking-methods/sdks/ios#legacy-automatically-tracked-events). We [announced the endpoint’s retirement](https://docs.mixpanel.com/changelogs#2026-01-26), and for some time `/decide` has returned a `410` response. Separately, `decide.mixpanel.com` and `api-decide.mixpanel.com` acted as aliases for our standard API hostnames. For example, `decide.mixpanel.com/track` ingested events the same way `api-js.mixpanel.com/track` does. Some customers had set up proxies or SDK configurations to send their traffic to these hostnames. On October 15 at 7:40 PM CDT, during the final cleanup of the `/decide` endpoint, we removed the DNS records for `decide.mixpanel.com` and `api-decide.mixpanel.com` and removed both hostnames from our load balancer. Before making the change, we confirmed that traffic to the `/decide` endpoint had dropped to zero. However, our monitoring measured traffic by endpoint rather than by hostname. It therefore did not show that other requests, such as `/track` and `/flags`, were still reaching Mixpanel through these hostnames. From then on, all requests to this hostname failed, including endpoints such as `/track`, `/engage`, `/groups`, and `/flags`. * **Events and Profiles:** Events, Profiles, and any data intended for [Ingestion API endpoints](https://docs.mixpanel.com/reference/ingestion-api) to these hostnames during this window never reached Mixpanel, so we do not have a copy to restore. If you retained this data elsewhere, such as in proxy logs or your data warehouse, you can re-send it to Ingestion API’s [/import](https://docs.mixpanel.com/reference/import-events), [/engage,](https://docs.mixpanel.com/reference/profile-set) and [/groups](https://docs.mixpanel.com/reference/group-set-property). * **Feature flags:** Feature flag requests sent to these hostnames failed. SDKs served the last stored variant if one existed, or otherwise the fallback value configured in your code. ### Timeline \(Central Time, October 2026\) * **October 15, 7:40 PM CDT:** The hostname removal is applied. Requests to `decide.mixpanel.com` and `api-decide.mixpanel.com` begin failing. * **October 16, 5:22 AM CDT:** We receive the first customer report. It is initially understood to be related to the planned `/decide` retirement. * **October 21, 11:42 AM CDT:** Following an increase in customer reports about tracking failing for proxies, we identify the hostname removal as the cause. * **October 21, 12:26 PM CDT:** We restore the hostnames. `/decide` remains retired. * **October 21, 1:51 PM CDT:** We confirm traffic to the restored hostnames has recovered. * **October 21, 8:34 PM CDT:** The incident is resolved. ### **Root cause** 1. During the `/decide` retirement, `decide.mixpanel.com` and `api-decide.mixpanel.com` were unintentionally removed. 2. These hostnames had been configured to accept all API traffic, not only `/decide` requests, and this behavior was undocumented. 3. Our monitoring tracked traffic to the `/decide` endpoint but not to these hostnames, so pre-change checks did not show that other traffic was still active. 4. Because the hostnames and the retired endpoint share a name, early customer reports were initially interpreted as expected effects of the announced `/decide` retirement. This delayed escalation. ### **What we’re changing** * **Monitoring and alerting:** We are adding traffic and error-rate monitoring and alerting for `decide.mixpanel.com` and `api-decide.mixpanel.com`, so failures are detected automatically rather than through customer reports. * **Hostname audit:** We are auditing all public API hostnames and routing aliases for similar undocumented entry points, and we will review new hostnames and aliases before they go live. We are also tracking traffic that arrives on any unexpected hostname. * **Safer removals:** Before any future change to a public hostname, we will confirm zero traffic at the hostname level, and we will identify and contact any projects still using it. * **Customer communication:** We will give customers advance notice of material infrastructure changes that affect public hostnames, including publishing them on a timeline in our changelog. **Already deployed:** * Restored `decide.mixpanel.com` and `api-decide.mixpanel.com` * `/decide` remains retired #### **Common questions** * **Was my data affected?** Only if your SDK or proxy sent requests to `decide.mixpanel.com` or `api-decide.mixpanel.com` between October 15 and October 21. Data sent there during that window were not received and cannot be restored by Mixpanel. If you retained a copy of that data, you can re-send it to Mixpanel using our Ingestion API endpoints such as `/import` for events. * **Do I need to change anything?** No, the domains work again. We recommend using `api.mixpanel.com` \(or `api-eu.mixpanel.com` / `api-in.mixpanel.com` for EU and India data residency\) as your API domain. * **Is** `/decide` coming back? No. It remains retired as announced, and it is separate from the `decide.mixpanel.com` hostname. We’re sorry for the disruption. If you have questions about your project, please contact your account team or Mixpanel Support.

We are currently experiencing delays in our data ingestion pipeline, which is affecting real-time data for projects enrolled in the US projects, resulting in delays for a subset of projects. While no data is being lost, our engineering team is actively investigating the matter and working to restore real-time functionality as quickly as possible. We appreciate your patience during this time. If you have any questions, please contact support.

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

We've identified the cause of the ingestion delay as an upstream issue with our cloud storage provider, Google Cloud, impacting a subset of US projects. Google has confirmed this as a high-priority issue on their end but hasn't provided an ETA yet. We've deployed mitigations to ensure a smooth recovery once it clears. No events are being lost. This is strictly an ingestion delay, all affected data will continue to be reprocessed once the issue is resolved.

Our metrics show ingestion is caught up and no longer experiencing delay. Google has not yet confirmed resolution of the underlying upstream issue on their end, so we’re continuing to monitor closely in case of recurrence.

No change since our last update, we continue to observe no active ingestion delay on our end, and all systems remain healthy. We’re continuing to monitor closely.

We are continuing to monitor for any further issues.

Systems have remained stable with no recurrence of the ingestion delay. We’re keeping a close eye on things while we wait for final confirmation from our upstream provider.

This incident has been resolved. The upstream issue with our cloud storage provider has been fixed, and our ingestion pipeline has been operating normally with no active delays. No events were lost throughout this incident, all affected data was fully reprocessed. Thank you for your patience throughout this incident.

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.

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

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

This incident has been resolved.

# 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 out of service. Service was restored, the impacted servers were brought back online, and the internal tooling was disabled. The remediations below add storage safeguards to remove internal tooling's ability to consume resources on query servers, and are designed to prevent this class of failure from happening again in the future. # What happened Mixpanel's query engine runs on a fleet of servers that each use a set of local storage volumes to cache the data needed to answer queries quickly. Separately, our engineers use diagnostic query replay tooling, a capability our engineers use to reproduce and debug query performance. While applying the diagnostic query replay tooling to a large, complex query, a software bug caused the query replay captures to fan out across the entire fleet instead of remaining confined to a single server. Additionally, it caused far more data than intended to be saved without timely eviction on a single server. Two factors then widened the impact of the issue: * A single full storage volume took a server fully out of service. Each server treats its cache as unhealthy if any one of its storage volumes crosses a usage threshold, even when all other volumes are healthy. The replay data was written to one specific volume on every server, so servers across the region failed their health checks nearly simultaneously. * Cleanup limits did not account for data size. The safeguard limiting replay data on disk counted items at the application level rather than bytes at the filesystem level, so a small number of unexpectedly large captures passed the check while consuming most of the volume’s capacity. Together, these allowed a single debugging workflow that normally has a negligible footprint to interrupt production query serving across the US region. # Timeline \(Pacific Time, August 26, 2026\) * **2:00 PM** — First oversized diagnostic replay capture was written; storage volumes began to reach their capacity and query success rate began to drop shortly after. * **2:17 PM** — Automated alerting paged the on-call engineer; investigation began immediately and additional engineers were engaged. * **2:39 PM** — Status page incident posted; in-app banner displayed at 2:40 PM. * **2:53 PM** — Root cause identified; recovery efforts began on the first affected server group. * **3:19 PM** — Query service restored for the vast majority of traffic; the final server group fully recovered at 3:27 PM. * **3:45 PM** — Incident resolved after a stable observation period. The diagnostic replay tooling that triggered the issue was fully disabled the same evening. # Root cause 1. **A software bug in our query replay tooling caused unbounded writes to production storage.** A recently deployed capability for reproducing queries mishandled a particular class of complex query, causing captures to spread to every query server in the region and to write far more data to the affected volumes than the design assumed. 2. **Replay files consumed disk capacity that query serving depends on.** The replay tooling wrote its files to the query servers' local disks, so runaway replay data exhausted storage capacity the servers need to answer queries. 3. **Safeguards only partially accounted for the behavior.** The cleanup policy for diagnostic replay data limited the number of items on disk, but not their total size, so it did not engage. Alerting on storage volumes flagged the growth but was not escalated as critical on a per-server basis, which delayed detection until query failures began. # What we're changing The end state we are building toward: internal diagnostic query replay data stored in dedicated object storage, placing no load on production query servers. Already deployed: * **Disabled the internal tooling** that caused the incident, and remediated the underlying issue so diagnostic captures are confined to a single server and the specific query class is handled correctly. * **Documented the targeted recovery procedure** used during the incident, i.e., clearing only the affected storage volume rather than restarting full server groups, in our operational runbooks, shortening recovery time if any volume’s capacity runs out in the future. In progress: * **Filesystem-level, size-based limits on diagnostic replay data**, capping total bytes on disk rather than item counts, so oversized captures are rejected or evicted before they can affect the volume’s capacity. * **Stricter storage alerting**, escalating per-server volume saturation as critical before it can affect query health checks. * **Moving query replay data to dedicated object storage,** so it consumes no resources on production query servers. # Common questions * **Was any data lost?** No. Data ingestion was unaffected throughout the incident: events continued to be collected, queued, and stored normally. Only the ability to query was interrupted. Once service was restored, all reports reflected complete data. * **Were saved reports, dashboards, or project settings affected?** No. The incident affected query execution only. Nothing stored in your project changed. * **Why did it affect multiple US projects at once?** The oversized diagnostic replay data written to every query server's disks at nearly the same time, and each server removes itself from service when any one volume fills. Preventing internal tooling from consuming query-server storage is a core part of our remediation work. * **How is this prevented going forward?** The tooling issue is resolved and the tooling remains disabled until size-based limits are in place. Storage alerting is being tightened so saturation is caught before it affects query serving. Structurally, we are moving diagnostic data off production query servers entirely, so internal debugging data will consume no storage on the servers responsible for queries processing. We apologize for the disruption and for the time reports were unavailable. Please reach out through your account team or support with any questions.

We are currently experiencing issues with populating event properties in dropdown menus. We appreciate your patience while our engineers work to restore functionality. If you have any questions, please contact [email protected]

We are continuing to work on a fix for this issue.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

We are aware that the Get-Report tool in the Mixpanel MCP server is currently failing when called with skip_results: false. Report metadata is unaffected. We are investigating the issue and will provide updates as we have them.

The issue has been identified and fix is being implemented.

A fix has been deployed and we're now monitoring the results. Report queries in the Mixpanel MCP server should be functioning normally. We'll continue to watch closely and provide a final update once we've confirmed full resolution.

This incident has been resolved.

We are currently experiencing issues with the Mixpanel agent within the webapp. Our engineering team has been alerted and is investigating the issue and working to restore its functionality. We appreciate your patience as we work to resolve this matter. If you have any questions, please contact support.

the team continues to investigate the issue and next steps. Thanks for your patience.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

We are currently experiencing delays in our data ingestion pipeline, which is affecting real-time data for projects enrolled in the US projects, resulting in delays for a subset of projects. While no data is being lost, our engineering team is actively investigating the matter and working to restore real-time functionality as quickly as possible. We appreciate your patience during this time. If you have any questions, please contact support.

We are continuing to investigate this issue.

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

We are continuing to work on a fix for this issue.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

# Summary Between approximately **11:35 PM PT on July 10 and 7:19 AM PT on July 11, 2026**, data ingestion for Mixpanel projects in the US region ran behind by up to ~2 hours. During this window, reports and dashboards temporarily showed incomplete data — recent time ranges could appear as sharp, artificial drops in metrics such as active users or revenue. **No data was lost.** All events were queued durably and processed in full once the backlog cleared; metrics returned to accurate values on their own, with no customer action required. The cause originated in our ingestion controls: for a small number of very high-volume projects, the ingestion rates we allowed had drifted out of alignment with the capacity provisioned for those projects. Large historical imports — entirely legitimate use of the platform — were therefore admitted faster than their infrastructure could absorb, and two properties of our pipeline turned that localized overload into a region-wide delay. The fixes below realign those controls so that any import, of any size, is automatically kept within safe bounds. # What happened Mixpanel's ingestion pipeline is sharded and multi-tenant: each project's data is distributed across a set of partitions sized for its expected volume, and for throughput, events from many customers are processed together in batches. This design delivers high efficiency, but it depends on one invariant: the rate at which we admit a project's traffic must match the capacity provisioned for it. When that invariant holds, even very large imports are absorbed smoothly. Here, it did not hold. A small number of very large historical data imports ran on projects whose allowed ingestion rates had, over time, grown well beyond their provisioned partition capacity. The excess volume concentrated onto specific partitions as **hot spots**, saturating the portion of the streaming fleet serving them. Two factors then widened the impact: * **Batched, multi-tenant processing amplified the hot spots.** Because events from many customers travel together in batches, slowness and failures on the overloaded partitions delayed unrelated customers' events sharing those batches. * **Automatic scale-up was ineffective.** Adding capacity cannot dissolve a hot spot of this kind, because the overloaded partitions stay pinned to the same infrastructure, and a capacity limit in a component of our streaming infrastructure prevented the added capacity from taking effect. Together, these turned what should have been a brief, self-healing slowdown into a multi-hour delay requiring manual intervention. # Timeline \(Pacific Time, July 10–11\) * **11:35 PM** — Automated alerting detected the ingestion backlog; on-call engineer engaged immediately. * **12:49 AM** — Status page incident posted; impact scoped to the US region only. * **1:23 AM** — The largest contributing import was paused. * **1:55–6:48 AM** — Progressive mitigations: additional traffic sources throttled, certain backlogged data deferred with the owning customer's agreement, failure isolation enabled in the pipeline, and affected infrastructure nodes replaced. * **7:19 AM** — Backlog fully processed; all projects current. Status page moved to monitoring, then resolved after a stable observation period. # Root cause 1. **Ingestion rate limits misaligned with provisioned capacity.** For the driving projects, the rates our platform admitted had grown out of step with the infrastructure provisioned for them, so legitimate high-volume imports were let in faster than their partitions could absorb. This is the systemic root cause. The imports themselves were a legitimate use of the platform. 2. **Batched, multi-tenant processing amplified the overload.** Failures on the overloaded partitions delayed unrelated customers' events sharing the same processing batches, spreading a localized problem across the platform. 3. **Traffic to the overloaded partitions could not be redistributed.** Partition-to-server assignment in the streaming layer was not load-aware, so the hot spots stayed pinned to the same servers regardless of fleet size — total capacity was sufficient, but it could not be brought to bear. A scaling limit in a component of our streaming infrastructure compounded this by preventing scale-up from adding capacity, which delayed diagnosis until engineers intervened manually. # What we're changing The end state we are building toward: **every project's ingestion limits automatically match its provisioned capacity, so that imports of any size, including full historical backfills and data warehouse syncs, can run without advance coordination, and one project's volume is prevented from affecting another's data freshness.**. Already deployed — improving our ingestion handling: * **Improved hot-spot handling.** Traffic distribution in the streaming layer is now load-aware, spreading concentrated load more evenly across the fleet, and individual problem items are now retried separately instead of holding up the rest of their batch — reducing, though not eliminating, the impact a localized overload can have on unrelated traffic. * **Re-provisioned the highest-volume workloads** onto appropriately sized infrastructure, prioritized by risk. Already deployed — changing how we operate the third-party streaming service: * **Audited and re-tuned the fleet's capacity profile** so individual servers have substantially more headroom for concentrated load, and worked with the provider to resolve the scaling limitation encountered during the incident. In progress: * **Capacity-aware rate limiting** — closing the gaps between individually granted project rate limits and each project's real provisioned capacity, extending rate limiting to ingestion paths that previously lacked it, and coupling any future limit increase to a capacity increase, which is designed to prevent this class of misalignment from recurring.. * **Finer-grained volume monitoring and alerting** so capacity misalignment is detected and corrected before it can affect any customer. * Evaluating stronger workload isolation/backlog recovery prioritization for bulk/backfill traffic paths, so historical imports have reduced impact on live traffic # Common questions * **Was any data lost?** No. Events were durably queued throughout the incident and were fully processed once the backlog cleared. Any metric drops seen during the window were a display artifact of the delay and self-corrected. * **Do I need to coordinate large imports or backfills with Mixpanel?** No — Our goal is for the platform to keep any import within safe rates automatically, so that backfills and warehouse syncs can run without scheduling or notice. We are still rolling out the capacity-aware controls that deliver this. In the meantime, if you are planning an unusually large import or backfill, we recommend coordinating with your account team so we can confirm capacity in advance. * **How is this prevented going forward?** The systemic fix is tightening the gaps between individually granted project rate limits and each project's real provisioned capacity, and extending rate limiting to the ingestion paths that previously lacked it — so overload of this kind is stopped at admission. In addition, the scaling limitation that prolonged the incident is fixed, the pipeline now retries individual problem items separately so a localized overload has far less impact on unrelated traffic, and bulk traffic is being further isolated from live traffic. * **Can individual projects be prioritized during recovery?** This capability did not exist during the incident — all projects recovered at the same rate. We are evaluating prioritization mechanisms for backlog recovery as part of our follow-up work. We apologize for the disruption and for the concern the temporarily depressed metrics caused. Please reach out through your account team or support with any questions.

Mixpanel is experiencing degraded performance with our Query API, including increased latency. You may see slow-loading reports or query errors. 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.

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

Query latency has stabilized, though our team continues to investigate the underlying cause of the degraded performance. We will continue to post updates as our investigation progresses. Thank you for your patience.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

Mixpanel is currently experiencing a disruption in the ability to invite and delete internal users within organizations. We appreciate your patience while our engineers work to restore this functionality. If you have any questions, please contact [email protected]

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

This incident has been resolved.

We are experiencing delays with our data ingestion and shuffling pipeline to projects with all projects. No data is being lost but as a result, real-time data is delayed. We appreciate your patience while our engineers work to restore real-time functionality. If you have any questions, please contact support

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

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

We are experiencing delays with our data ingestion and shuffling pipeline to projects with US & India data residency. No data is being lost but as a result, real-time data is delayed. We appreciate your patience while our engineers work to restore real-time functionality. If you have any questions, please contact support

We have now identified an ingestion delay for EU projects, and are continuing to investigate the issue. Thank you for your patience.

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

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

A subset of users are currently facing issues accessing boards that they previously had access to view. Our Engineering team is actively investigating and will update shortly.

The issues has been identified and a fix is being implemented. As a workaround boards can be explicitly shared with users who are having issues viewing them currently.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

We are experiencing degraded performance with our Query API, including increased latency. You may see slow-loading reports, incomplete query results, query errors, or data discrepancies. 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.

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

We are continuing to work on a fix for this issue.

We've continued to make progress on the issue affecting some US projects. Query success rates have returned to normal levels, and the related processing delays have also recovered. A subset of affected projects may still see incomplete data in query results while our recovery process runs. We're actively working on this and will share another update in 2 hours. Impact remains limited to our US region. We do not currently believe any data has been permanently lost.

Recovery is progressing well. Query success rates remain at normal levels, and missing data has now been restored for a portion of affected projects. We're continuing the recovery process for the remaining affected projects and currently estimate full recovery within approximately 3–5 hours. Some customers may still see incomplete data in query results until this work is complete.

We are continuing to work on resolving this issue. Our current estimate for full recovery is approximately 3–5 hours. Some customers may still see incomplete data in reports until recovery is complete. We will continue to provide updates.

Recovery is continuing to progress and query latency has returned to normal levels. Our current estimate for full recovery is approximately 3–4 hours. Some customers may still see incomplete data in reports until recovery is complete. We will continue to provide updates.

We are investigating an increase in query latency that appears to be unrelated to the ongoing recovery. You may experience slower-loading reports. Our team is actively looking into the cause and we will provide an update shortly. Recovery is continuing to progress. Our current estimate for full recovery is approximately 3–4 hours. Some customers may still see incomplete data in reports until recovery is complete. We will continue to provide updates.

Query latency has returned to normal levels. We are continuing to monitor.

Query latency has returned to normal levels and has been resolved. Recovery is continuing to progress, and our current estimate for full recovery is approximately 4–5 hours. Some customers may still see incomplete data in reports until recovery is complete. We will continue to provide updates.

Recovery is continuing to progress. Our current estimate for full recovery is approximately 1-2 hours. Some customers may still see incomplete data in reports until recovery is complete. We will continue to provide updates.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

# Mixpanel RCA: Transient Data Access Issue, May 14, 2026 ## Summary On Thursday, May 14, 2026 at approximately 2:30 PM PT, a routine but infrequent cleanup operation in Mixpanel's storage system mistakenly removed a portion of production data files in addition to the unused files it was intended to remove. Some customers experienced query errors during the hours that followed. We detected the issue within minutes, deployed mitigations the same evening that returned query success rates and latency to normal, and restored the affected files from backup by 5:15 PM PT on Friday, May 15. Mixpanel's ingestion pipeline was not affected and no event data was lost in transit. ## What happened This incident was triggered by a storage cleanup procedure that runs periodically to remove files no longer referenced by Mixpanel's metadata. The procedure was more involved than usual: it followed a recent enhancement to our file storage strategy that left a set of unused files behind in our storage backend, and addressing them required extending our standard cleanup approach to cover a new code path. As part of executing this extended cleanup, an engineer generated the list of files to delete using a SQL query whose date filter was not strictly earlier than the reference snapshot it was being compared against. As a result, a small set of legitimate production files that had been written in the gap window between the snapshot and the filter date were incorrectly classified as unused and removed. The deletion ran for roughly half an hour before internal alerting caught the resulting query failures and the operation was stopped. The trigger was operator error against an ambiguous runbook, not a defect in the live serving path or in our ingestion pipeline. ## Customer impact Impact unfolded in two phases. The first phase ran from Thursday at approximately 2:30 PM PT until 8:11 PM PT — roughly five and a half hours. During this window, customers across the platform may have seen slower or failed queries when their requests touched files that had been deleted. The breadth and severity varied by project depending on which data each query touched. By 8:11 PM PT, mitigations had fully rolled out — queries automatically retried against an alternate availability zone, and a fallback path was put in place to serve missing files from a backup datastore. After this point, query success rate and latency returned to normal. The second phase lasted from 8:11 PM PT Thursday through approximately 5:15 PM PT Friday, May 15. During this window, fewer than 2% of customers were still affected — specifically, those whose deleted files had not yet been fully restored from backup. The vast majority of these files were recovered by Friday afternoon. A small number of projects \(under 30\) had files that could not be fully recovered from backup, and we are following up with those accounts directly. ## Timeline \(Pacific Time\) * May 14, 2:30 PM — Cleanup operation begins * May 14, 3:11 PM — Internal alerting flags query failures; the cleanup operation is stopped within minutes * May 14, 4:07 PM — Status page banner posted * May 14, 4:45 PM — Mitigation deployed: queries automatically retry against an alternate availability zone * May 14, 7:12 PM — Mitigation deployed: queries fall back to a backup datastore for missing files * May 14, 8:11 PM — Query success rate and latency fully restored to normal levels * May 15, 5:15 PM — File restore from backup complete; status page banner resolved ## Why this happened Several contributing factors lined up. The runbook for this cleanup procedure had ambiguous wording around the ordering and timing of its inputs. It had been recently authored to handle the new file-storage code path and had not gone through a formal review before being used. Our cleanup tooling did not programmatically enforce the safety invariant that the date filter must be strictly before the reference snapshot. That invariant lived only in operator-authored SQL. The extended cleanup was being executed in parallel across two storage layers by two different engineers, which increased the room for error. ## What we're doing to prevent recurrence We have already made or have actively in flight the following changes. We are adding programmatic safeguards to our cleanup tooling so that an input set whose date filter is not safely before the reference snapshot is rejected before any deletion occurs, along with a reconciliation step that flags any production-referenced file before deletion proceeds. Destructive cleanup operations will now run in phased stages, starting with internal projects and pausing for a holding period before any broader execution. Destructive storage operations now require a second engineer to sign off on the exact deletion set and to be present during execution, matching the practice we already follow for database migrations. We have updated the cleanup runbook with explicit guidance on input timing, required safety buffers, and an enforced review process for any runbook covering a destructive operation. Longer term, we are working to eliminate the manual portion of this cleanup procedure entirely and route it through our existing automated cleanup infrastructure, so the class of failure that produced this incident is no longer reachable through human input. ## Closing Reliability and data integrity are foundational to the trust our customers place in Mixpanel, and we recognize the impact this incident had on the teams who rely on us. We are sorry for the disruption. If you have questions about how this incident may have affected a specific project, please reach out to your account team or Mixpanel Support.

Data Volume Monitoring is again experiencing degraded performance due to a recurring upstream provider disruption. We're mitigating now.

We are continuing to work on a fix for this issue.

This incident has been resolved.

We are currently investigating an issue that leads to degraded performance of Data Volume Monitoring in a subset of US-based projects. We truly appreciate your patience and apologize for the inconvenience. If you have any questions, please contact support (https://mixpanel.com/get-support).

An upstream service provider outage is causing this issue. We are deploying a fix to mitigate the disruption.

A fix has been implemented, and we are monitoring the result.

This incident has been resolved.

A subset of projects are experiencing issues exporting data to the Snowflake warehouse via Mixpanel pipelines. We are currently investigating this issue.

We have identified the issue affecting Snowflake pipeline exports for a subset of projects, and our engineering team is working on a resolution.

This incident has been resolved.

We are currently experiencing an interruption with our credit card processing. Our engineers have identified the issue and are working on a fix.

A fix has been deployed, and all impacted accounts have had their billing re-run. If you continue to receive errors, please ensure the card on file is up to date. If you are still experiencing issues, please submit a support ticket.

This incident has been resolved.

Mixpanel is experiencing increased query latency for projects with EU residency, which may result in HTTP 500 responses when querying or saving reports. Projects with US and IN residency remain unaffected. Our engineering team is working on a resolution.

A fix has been implemented and we are monitoring the results.

This incident has been resolved.

We are currently experiencing issues with loading Mixpanel.com and are working to restore service as quickly as possible. Our team is investigating the issue and will provide updates as soon as we have more information. Thank you for your patience.

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

A fix has been implemented and we are monitoring the results.

This incident has been resolved. If Mixpanel is still not loading, please clear your cache and cookies.