ClickHouse Outage History

Started May 22, 2026, 04:11 PM UTC· resolved May 22, 2026, 04:50 PM UTC

1. identified May 22, 2026, 04:11 PM UTC

   We've noticed some instances are stuck in provisioning state due to capacity issues in AWS us-east-1 region. ClickHouse Cloud team is working on possible remediations, but we advise do not create new instances in this region until capacity problem is addressed on AWS side.

2. resolved May 22, 2026, 04:50 PM UTC

   Affected instances have been corrected in the AWS us-east-1 region. We apologize for the disruption this issue caused. We are committed to the reliability of all ClickHouse Cloud services and appreciate your understanding as we continue to improve our systems and operations. If you have questions or need information on a specific ClickHouse service, please contact support "contact support": https://clickhouse.cloud/support.

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Started May 18, 2026, 12:31 PM UTC· resolved May 20, 2026, 06:32 PM UTC

1. investigating May 18, 2026, 12:31 PM UTC

   We are currently experiencing capacity constraints in the affected GCP region. As a result, users may encounter issues when creating new clusters or operating existing clusters in this region. Our team is actively working on mitigation to restore normal capacity and minimize customer impact. We will continue to provide updates as more information becomes available.

2. resolved May 20, 2026, 06:32 PM UTC

   No more capacity issues observed for us-east1 region. Provisioning and scaling should work as usual.

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Started May 08, 2026, 02:46 AM UTC· resolved May 09, 2026, 09:48 AM UTC

1. investigating May 08, 2026, 02:46 AM UTC

   AWS Region (US-EAST-1) is experiencing disruptions. We are actively monitoring the situation and following updates from AWS. Please follow the https://health.aws.amazon.com/health/status page for latest updates.

2. resolved May 09, 2026, 09:48 AM UTC

   AWS has mitigated the disruption affecting the US-EAST-1 availability zone. We will continue monitoring to ensure stability.

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Started May 05, 2026, 01:03 PM UTC· resolved May 05, 2026, 03:14 PM UTC

1. investigating May 05, 2026, 01:03 PM UTC

   We are currently experiencing issues provisioning new services in Azure. Existing services are not impacted.

2. resolved May 05, 2026, 03:14 PM UTC

   We have resolved the issue and are no longer seeing impact to services

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Started Apr 28, 2026, 06:44 PM UTC· resolved Apr 30, 2026, 02:12 AM UTC

1. investigating Apr 28, 2026, 06:44 PM UTC

   We are currently investigating connection issues affecting some customers, resulting in connection timeouts when connecting to ClickHouse. The issue has been isolated to infrastructure in the us-east-2 region. We have received multiple high-severity reports and are treating this with priority. Our engineering team is actively working to mitigate the issue and restore normal connectivity. We will provide further updates as more information becomes available.

2. monitoring Apr 28, 2026, 07:18 PM UTC

   The connection issues affecting some customers in the us-east-2 region have been mitigated, and services are currently operating normally. We are continuing to monitor the situation closely to ensure stability and prevent recurrence. We will provide further updates if there are any changes.

3. resolved Apr 28, 2026, 07:41 PM UTC

   The connection issues affecting some customers in the us-east-2 region have been resolved, and services are operating normally.

4. investigating Apr 28, 2026, 08:34 PM UTC

   We are seeing a recurrence of the connection issues affecting some customers in the us-east-2 region, resulting in connection timeouts. Our team is actively investigating and working to mitigate the issue as a priority. We will provide further updates as more information becomes available.

5. monitoring Apr 28, 2026, 10:32 PM UTC

   A subset of services in us-east-2 experienced intermittent connection timeouts earlier today caused by exhaustion of network resources on one of our regional load balancers. We have applied mitigations to restore connectivity and the service is currently operating normally. We are continuing to work with on rolling out additional capacity and safeguards to prevent recurrence. Customers who continue to see connection issues should reach out to support.

6. resolved Apr 30, 2026, 02:12 AM UTC

   We have resolved the incident.

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Started Apr 19, 2026, 01:39 PM UTC· resolved Apr 20, 2026, 10:18 PM UTC

1. identified Apr 19, 2026, 01:39 PM UTC

   We are experiencing capacity constraints for new workloads on GCP us-east1. Currently running and created instances are not affected.

2. identified Apr 19, 2026, 02:29 PM UTC

   Capacity constraints of GCP us-east1 region do not allow to allocate more instances in the region. We are working with a cloud provider to resolve capacity issues. Running services are working without issues, but new instance creation is disabled.

3. resolved Apr 20, 2026, 10:18 PM UTC

   Incident has been resolved

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Started Apr 17, 2026, 03:12 PM UTC· resolved Apr 18, 2026, 11:13 AM UTC

No vendor updates were posted for this incident.

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Started Apr 16, 2026, 10:11 PM UTC· resolved Apr 16, 2026, 11:55 PM UTC

1. identified Apr 16, 2026, 10:11 PM UTC

   Impacting services on ClickHouse Cloud across multiple regions.

2. monitoring Apr 16, 2026, 11:55 PM UTC

   Fix is rolled out on all regions

3. resolved Apr 16, 2026, 11:55 PM UTC

   Fix has been applied on all regions.

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Started Apr 08, 2026, 04:09 PM UTC· resolved Apr 08, 2026, 10:24 PM UTC

1. investigating Apr 08, 2026, 04:09 PM UTC

   We spotted an issue where creation of new ClickHouse instances is delayed or stuck. Team is investigating the issue and already applying a temporary remediation.

2. identified Apr 08, 2026, 04:21 PM UTC

   We identified the issue and applying the remediation. The issue was caused by manual operation performed on the AWS Route53 configuration earlier today. It caused increase in the rate of requests to Route53 API, leading to throttling and retries (including provisioning of new ClickHouse instances).

3. monitoring Apr 08, 2026, 04:49 PM UTC

   We applied the fix for a subset of regions and see signs of improvements. We are gradually applying the fix to all other regions and monitoring the status.

4. monitoring Apr 08, 2026, 07:20 PM UTC

   ClickHouse continues to scale external-dns in each region. The following regions are complete and operating normally: us-east-1, af-south-1, ap-east-1, ap-northeast-1, ap-northeast-2, ap-south-1 Additional regions are in progress or will begin shortly, and the ETA to complete the remaining regions is estimated as 3-5 hours: us-east-2, us-west-2, eu-central-1, eu-west-1, eu-west-2, ap-southeast-1, ap-southeast-2, il-central-1

5. resolved Apr 08, 2026, 10:24 PM UTC

   This issue is resolved. External-DNS has been scaled for all impacted regions.

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Started Mar 16, 2026, 11:28 AM UTC· resolved Mar 16, 2026, 12:59 PM UTC

1. investigating Mar 16, 2026, 11:28 AM UTC

   The ClickStack UI (https://hyperdx.clickhouse.cloud/) is currently not loading. We are investigating.

2. resolved Mar 16, 2026, 12:59 PM UTC

   The incident was caused by an overloaded database. The instance was scaled up. It is stable again now. We are investigating heavy queries and will apply improvements.

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Started Mar 03, 2026, 08:39 AM UTC· resolved Mar 03, 2026, 11:00 AM UTC

1. investigating Mar 03, 2026, 08:39 AM UTC

   We are currently experiencing degraded operational performance in ClickPlane. Data ingestion is functioning as expected, however some operational features may experience increased latency or intermittent behavior. Our team is actively investigating the issue and working on mitigation. We will provide further updates as soon as more information becomes available.

2. identified Mar 03, 2026, 10:04 AM UTC

   We have mitigated the impact affecting ClickPlane in the us-east-1 region. Operational performance in this region has stabilized, and ingestion continues to function normally. We are continuing to monitor the system closely to ensure stability and working to fix the problem on us-east-2

3. identified Mar 03, 2026, 10:20 AM UTC

   We have mitigated the operational impact affecting ClickPipes in the us-east-1 region. Operational performance in this region has stabilized, and ingestion continues to function normally. We are continuing to monitor the system closely to ensure stability. Further updates will be provided if necessary.

4. resolved Mar 03, 2026, 11:00 AM UTC

   The operational impact affecting ClickPipes in the us-east-1 region has been fully resolved. All systems are operating normally, including ingestion and operational functionality. We will continue to monitor the platform to ensure ongoing stability. Thank you for your patience.

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Started Mar 01, 2026, 01:29 PM UTC· resolved May 22, 2026, 09:06 AM UTC

1. investigating Mar 01, 2026, 01:29 PM UTC

   There is a partial outage in AWS me-central-1 that is impacting our clusters in that region. As a result, services hosted in me-central-1 may be affected. We are actively investigating to assess the scope of the impact and implement mitigation measures where possible. For reference, please see the AWS Health Dashboard: https://health.aws.amazon.com/health/status

2. investigating Mar 01, 2026, 03:36 PM UTC

   We would like to provide an update regarding the ongoing partial outage in the me-central-1 region. The impact appears to be primarily concentrated in a single Availability Zone (AZ), although we have observed limited issues in other AZs. Approximately 33% of our instances in the region are currently unavailable, resulting in reduced capacity. Services remain operational but are running in a degraded state. Additionally, we are currently unable to create new instances or perform operations on existing clusters. We are actively monitoring the situation and evaluating mitigation options. Further updates will be shared as more information becomes available. For reference: https://health.aws.amazon.com/health/status

3. investigating Mar 02, 2026, 11:12 AM UTC

   We would like to provide a further update regarding the ongoing partial outage in the me-central-1 region. According to the latest information from AWS, an additional Availability Zone (AZ) is now impacted. The situation in the region has deteriorated, and the overall impact to services is significantly greater than previously reported. At this time, a high percentage of requests are failing, and customer-facing services in the region are experiencing severe degradation. Additionally, our monitoring systems in the region are also impacted, which is limiting real-time visibility into certain metrics and increasing operational complexity. Based on the most recent AWS updates, the estimated time to resolution remains many hours. We are actively tracking AWS communications and evaluating all available mitigation options to reduce customer impact wherever possible. We will provide further updates as soon as more information becomes available. For reference: https://health.aws.amazon.com/health/status

4. investigating Mar 02, 2026, 02:31 PM UTC

   We would like to provide an update regarding the ongoing incident in the me-central-1 region. The situation has further deteriorated and we are now experiencing a full outage in the region. Due to the loss of 2 out of 3 Availability Zones, the affected clusters have lost quorum. As a result, data ingestion is not possible at this time. Access to services in the region is now severely limited and operating in read-only mode where possible. We continue to closely monitor AWS updates. According to the latest communications from AWS, the estimated time to resolution is not at least a day. Our engineering teams are actively evaluating all available mitigation and recovery options. We will provide further updates as soon as more information becomes available. If you require further assistance or have urgent concerns, please contact our Support team through the usual support channels. For reference: https://health.aws.amazon.com/health/status

5. investigating Mar 09, 2026, 11:34 PM UTC

   AWS Middle East (UAE) Region (ME-CENTRAL-1) is still experiencing severe disruptions. We are actively monitoring the situation and following updates from AWS. Please follow the https://health.aws.amazon.com/health/status page for latest updates.

6. resolved May 22, 2026, 09:06 AM UTC

   ClickHouse Cloud no longer supports AWS me-central-1 "AWS me-central-1": https://health.aws.amazon.com/health/status?eventID=arn:aws:health:me-central-1::event/MULTIPLE_SERVICES/AWS_MULTIPLE_SERVICES_OPERATIONAL_ISSUE/AWS_MULTIPLE_SERVICES_OPERATIONAL_ISSUE_5E6B8_EF2498889B5. Customers who were running services in this region have been migrated to their region of choice, and the region is no longer available for selection. No further updates will be posted for this region.

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Started Feb 27, 2026, 08:07 AM UTC· resolved Feb 27, 2026, 09:49 AM UTC

1. identified Feb 27, 2026, 08:07 AM UTC

   We have spotted an issue where idled ClickHouse instances in Azure regions can't be woken up. Team is already working on a fix. We expect the fix to be rolled out soon.

2. monitoring Feb 27, 2026, 09:26 AM UTC

   A fix is deployed. Services waking up now (from idle or starting from stopped) will start as normal. Services that are currently stuck in waking will come up soon.

3. monitoring Feb 27, 2026, 09:27 AM UTC

   Azure region westus3 is fully operational again. All services previously stuck in waking up have started.

4. monitoring Feb 27, 2026, 09:46 AM UTC

   Azure eastus2 is fully operational again (all services stuck in waking started).

5. resolved Feb 27, 2026, 09:49 AM UTC

   All services stuck in waking in all azure regions are started now.

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Started Feb 21, 2026, 11:50 AM UTC· resolved Feb 21, 2026, 02:26 PM UTC

1. investigating Feb 21, 2026, 11:50 AM UTC

   We are investigating the issue where instances created in AWS us-east-1 have wrong configuration, causing provisioning to stuck or to have wrong number of replicas. This affects only a small number of instances created in last ~25 hours

2. identified Feb 21, 2026, 12:01 PM UTC

   We have identified the possible cause of the issue and applying remediation for stuck/misconfigured instances. We do not recommend creating new instances in us-east-1 until the incident is resolved.

3. identified Feb 21, 2026, 12:29 PM UTC

   We have fixed the root cause of the issue. Newly created instances have correct configuration now and are expected to provision successfully. Instances that currently are stuck or have wrong configuration are being corrected by the ClickHouse team. We are closely monitoring creation of new instances and remediation for existing stuck instances.

4. monitoring Feb 21, 2026, 02:17 PM UTC

   Configuration for all affected instances was corrected. We are monitoring the health status of these instances.

5. resolved Feb 21, 2026, 02:26 PM UTC

   All systems operational. We apologize for the disruption this issue caused. We are committed to the reliability of all ClickHouse Cloud services and appreciate your understanding as we continue to improve our systems and operations. If you have questions or need information on a specific ClickHouse service, please contact support "contact support": https://clickhouse.cloud/support.

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Started Feb 12, 2026, 04:37 PM UTC· resolved Feb 12, 2026, 06:16 PM UTC

1. investigating Feb 12, 2026, 04:37 PM UTC

   There is an ongoing incident affecting CDC ClickPipes in us-east-1. The team is investigating.

2. investigating Feb 12, 2026, 05:02 PM UTC

   The incident is affecting all regions for CDC ClickPipes only. The team continues to investigate.

3. identified Feb 12, 2026, 05:18 PM UTC

   We have identified the issue and are working on a fix.

4. identified Feb 12, 2026, 05:34 PM UTC

   We are rolling out the fix region per region. ap-southeast-2 is now fully operational.

5. identified Feb 12, 2026, 05:42 PM UTC

   We have fixed the issue and rolled it out across all regions. In the next few minutes, you should see CDC ClickPipes recover and catch up on the replication backlog.

6. monitoring Feb 12, 2026, 05:43 PM UTC

   We continue monitoring the recovery of ClickPipes across all regions, after rolling out the fix to all affected CDC ClickPipes.

7. resolved Feb 12, 2026, 06:16 PM UTC

   After verifying that all affected ClickPipes have recovered, the incident can be declared as resolved. We will be sharing an RCA in the next few days with the affected customers. We sincerely apologize for the disruption caused.

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Started Jan 31, 2026, 10:03 AM UTC· resolved Feb 03, 2026, 10:09 AM UTC

1. investigating Jan 31, 2026, 10:03 AM UTC

   We are investigating a partial outage affecting services in the AWS region us-east-1.

2. identified Jan 31, 2026, 10:55 AM UTC

   Our engineering team has identified the root cause of the service disruption affecting ClickHouse some instances in US-EAST-1. We are currently deploying a fix across the region. ClickHouse instances should begin resuming normal operations within the next 10-30 minutes. We will continue to monitor closely and provide updates as services are restored.

3. resolved Jan 31, 2026, 11:51 AM UTC

   This issue is now fixed.

4. investigating Feb 01, 2026, 09:27 AM UTC

   We are investigating an elevated error rate in AWS us-east-1 and eu-west-2.

5. resolved Feb 01, 2026, 09:45 AM UTC

   All components are operational after the restart of an internal component (Cilium) in the affected regions. The team is working on an RCA.

6. investigating Feb 02, 2026, 09:35 AM UTC

   We are investigating an elevated error rate in AWS eu-central-1 and ap-southeast-1.

7. monitoring Feb 02, 2026, 10:23 AM UTC

   The team mitigated the issue in affected regions and continues to investigate the root cause.

8. monitoring Feb 02, 2026, 06:13 PM UTC

   Additional configuration changes have been applied to prevent the recurrence of this issue. The team continues to monitor the systems.

9. monitoring Feb 02, 2026, 10:47 PM UTC

   We believe this is related to a known bug in the version of our networking stack currently in use and are mitigating the issue by resetting this layer across all AWS regions. The team continues to monitor all systems closely.

10. monitoring Feb 03, 2026, 03:06 AM UTC

    We have completed the reset of the networking stack across all regions and continue to monitor all systems closely.

11. resolved Feb 03, 2026, 10:09 AM UTC

    We have confirmed that all systems are stable and operating normally. The networking configuration has been fully restored across all regions, and we have implemented additional monitoring and safeguards to prevent recurrence. We will continue to monitor systems closely over the coming days as part of our standard post-incident procedures, and share an RCA as soon as possible.

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Started Jan 31, 2026, 10:03 AM UTC· resolved Jan 31, 2026, 11:51 AM UTC

No vendor updates were posted for this incident.

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Started Jan 30, 2026, 11:55 AM UTC· resolved Jan 30, 2026, 01:27 PM UTC

1. investigating Jan 30, 2026, 11:55 AM UTC

   We are investigating issue in AWS ap-south-1 region where: - Admin operations on instances might be delayed or not progressing - Billing metrics not updated - Some dashboards in Control Plane UI not loading or loading slowly

2. identified Jan 30, 2026, 12:08 PM UTC

   The team has identified the issue and working on the fix. ClickHouse instances are expected to be reachable and working (except autoscaling functionality).

3. monitoring Jan 30, 2026, 12:56 PM UTC

   We are seeing signs of recovery, and closely monitoring.

4. monitoring Jan 30, 2026, 01:16 PM UTC

   User dashboards and autoscaling operations should be recovering now. Old data is already available, last hours are being backfilled.

5. resolved Jan 30, 2026, 01:27 PM UTC

   The issue is fully resolved. The latest data in ControlPlane UI monitoring dashboards was backfilled and should be available. The issue seems to be related to networking issues on underlying VMs. Team is investigating the root cause to make sure it won't happen again or in other regions.

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Started Jan 26, 2026, 05:17 PM UTC· resolved Jan 26, 2026, 05:28 PM UTC

No vendor updates were posted for this incident.

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Started Jan 23, 2026, 11:43 AM UTC· resolved Jan 24, 2026, 12:44 AM UTC

No vendor updates were posted for this incident.

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Started Dec 15, 2025, 06:20 PM UTC· resolved Dec 15, 2025, 09:16 PM UTC

No vendor updates were posted for this incident.

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Started Nov 20, 2025, 02:29 PM UTC· resolved Nov 20, 2025, 03:25 PM UTC

No vendor updates were posted for this incident.

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Started Nov 14, 2025, 01:08 PM UTC· resolved Nov 14, 2025, 02:28 PM UTC

No vendor updates were posted for this incident.

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Started Nov 12, 2025, 08:59 AM UTC· resolved Nov 12, 2025, 09:26 AM UTC

No vendor updates were posted for this incident.

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Started Nov 07, 2025, 10:59 PM UTC· resolved Nov 08, 2025, 02:02 AM UTC

No vendor updates were posted for this incident.

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