Is Apigee Down?

# Incident Report ## Summary On Monday, 19 Oct 2026 at 22:53 US/Pacific (Tuesday, 20 Oct 2026, 06:53 BST), a data center facility that hosts europe-west2-b, a zone within the europe-west2 cloud region, experienced an external electrical power disruption. This resulted in service unavailability for workloads located in this zone. The subsequent failover of these workloads to unaffected zones and alternate regions caused transient latency and elevated error rates across the broader europe-west2 region. The resolution of the main impact was completed within 6 hours and 8 minutes. ## Root Cause **Facility architecture and background:** The data center facility in the UK region hosts Cloud clusters serving the europe-west2-b zone, which form part of the multi-zonal europe-west2 Cloud region. The site relies on a 2N utility power architecture—where the facility has complete duplicate power paths for every critical load—backed by a central high-voltage generator bank managed by a dual-redundant Programmable Logic Controller (PLC). Primary utility power is supplied to the facility via two independent feeders (A and B), supplemented by a standby utility connection configured for manual campus-wide transfer during maintenance operations or emergency events. The two high-voltage primary feeders (A and B) terminate at separate primary intake switchboards capable of closed-loop operation if either board is taken offline. Switching between the primary and standby utility providers utilizes open transitions and key interlocks to prevent parallel connections across sources. Uninterruptible Power Supply (UPS) battery systems provide approximately five minutes of autonomous runtime. This bridge power ensures uninterrupted operation while the PLC detects utility undervoltage events, initiates diesel generator startup, synchronizes the generators, and transfers the site load. Prior to the utility disruption, the facility had been placed in a temporary single-feed (1N) bridged maintenance posture on the primary utility. Circuit breaker feeder B was physically opened to allow for corrective repairs following issues identified during a quarterly generator load test on 14 Oct 2026. Consequently, primary utility feed A was supporting the total critical load while the feed B breaker remained in an open position to allow repairs to be conducted on the B feeder pathway. **Root Cause:** On Monday, 19 Oct 2026 at 22:53 US/Pacific (Tuesday, 20 Oct 2026, 06:53 BST), the primary utility provider experienced an outage on primary utility feed A, caused by an external underground cable fault on the utility network outside the data center facility. Following the loss of primary utility feed A, a voltage-sensing design flaw and PLC misconfiguration prevented the facility’s generator plant from receiving an automatic start signal to assume the critical load. Consequently, static UPS battery banks sustained the critical load as intended until their reserves were used up, leading to a loss of power across the data halls. The investigation of the PLC configuration identified the root cause as a misconfiguration of the PLC logic that did not verify both an undervoltage condition and physical breaker position for both utility feeders. Instead, the PLC undervoltage sensing inputs were wired upstream (line side) of the isolated utility feed breakers. The PLC was programmed to verify whether voltage was present on the line side of the feeder before commanding a generator start. At the time of the power event on 19 Oct 2026, the Utility feed B remained energized upstream while its incomer feed was in open position. Consequently, the active and standby master PLCs, which were running identical control logic, sensed live voltage from feed B through shared upstream sensors on the disconnected path. As a result, the PLC logic indicated that a healthy utility source was available, even though the primary and secondary distribution feeds were de-energized, and did not issue a start command to the generator plant. The onsite facilities team attempted to execute a remote load transfer via the PLC; however, the system inhibited the action due to the live upstream voltage reading on feed B. Recognizing that the UPS battery reserves would be used up before further remote operations could be resolved, the team transferred the facility load to the standby utility source, restoring the critical load that was lost once batteries depleted during this process. Once utility power was restored via the standby utility source, and UPS batteries started recharging, the onsite facility teams and OEM vendors reconfigured and validated PLC functionality on both undervoltage and breaker status. Following the initial detection of the power outage, Google engineering teams initiated efforts to address failover issues and lay the groundwork for service restoration. Once the utility feed, UPS systems, and generator capabilities were successfully restored, engineers initiated the recovery procedure to bring europe-west2-b services back online. ## Remediation and Prevention The sequence of events leading to customer impact was as follows: * **19 Oct 22:53 US/Pacific (20 Oct 2026, 06:53 BST) -** An electrical power disruption occurred at the data center facility hosting availability zone europe-west2-b, and a PLC (Programmable Logic Controller) startup fault prevented facility emergency generators from assuming the electrical load. Facility load continued to be supported by UPS battery banks until the batteries were depleted. * **19 Oct 23:00 US/Pacific (20 Oct 2026, 07:00 BST) - Impact start -** As battery backups were used up, physical host servers, local storage infrastructure, and network aggregation hardware in availability zone europe-west2-b lost power, causing instances, database replicas, and worker nodes in that zone to become immediately unreachable. * **19 Oct 23:04 US/Pacific (20 Oct 2026, 07:04 BST) -** Google engineers were alerted to the disruption via automated monitoring systems and probers, which detected elevated API error ratios, job submission timeouts, and loss of infrastructure reachability in zone europe-west2-b. Engineering teams immediately mobilized to isolate the affected infrastructure and commence recovery. * **19 Oct 23:09 US/Pacific (20 Oct 2026, 07:09 BST) -** Regional traffic-routing mechanisms and client applications initiated automated failover toward available infrastructure in adjacent availability zones within the region. * Cross-zone remote procedure calls from regional service control planes directed to metadata and catalog components in the offline zone encountered timeouts, causing initial job submission stalls and API latency spikes. * The sudden influx of redirected query executions, high-availability database failovers, and compute workloads saturated available compute slots and processing capacity in other availability zones, creating elevated admission queues, delayed database failover completions, and intermittent 500 and 503 API errors across the region. * **Traffic Isolation:** Google engineers isolated the offline availability zone (europe-west2-b) by adjusting regional service routing away from the affected infrastructure, preventing cross-zone client requests from timing out against offline endpoints. * **Workload Reprioritization and Resource Safeguards:** Engineers adjusted scheduler allocations and capacity limits across unimpacted infrastructure to prioritize active customer reservations, reduce resource contention on execution slots, and relieve queue backlogs for regional workloads. * **19 Oct 23:54 US/Pacific (20 Oct 2026, 07:54 BST) - Utility Power Restoration-** Power supply from the standby utility source was restored and power restoration to the data hall began. * **20 Oct 00:20 US/Pacific (20 Oct 2026, 08:20 BST) - Datahall Power Restoration-** Utility power was re-established to the datahalls. Mains utility power normalized; power feed to data hall verified. Following this, the site operations and engineering teams focused on and completed a reset and tested the emergency backup generator automation controllers to restore facility power. * **20 Oct 00:40 US/Pacific (20 Oct 2026, 08:40 BST)-** Clusters began to recover, cluster manager systems started rescheduling compute jobs. * **20 Oct 00:45 US/Pacific (20 Oct 2026, 08:45 BST) -** Network devices were back online. * **20 Oct 00:50 US/Pacific (20 Oct 2026, 08:50 BST) -** Due to the immediacy of power loss, storage devices with unclean shutdowns began recovery. Responders recognized this and chose not to restore services that would otherwise make this worse. Because of the large volume of storage devices involved, this process required a substantial period to finish prior to restoring service to customers. * **20 Oct 03:13 US/Pacific (20 Oct 2026, 11:13 BST)-** Power redundancy was verified and the storage infrastructure was sufficiently restored to prepare the initiation of controlled traffic re-admission. The remaining storage systems continued recovery operations. * **20 Oct 03:45 US/Pacific (20 Oct 2026, 11:45 BST)-** Once system health and storage integrity were verified, engineers executed gradual, controlled traffic re-admission back to zone europe-west2-b allowing accumulated job backlogs to clear smoothly. * **20 Oct 04:11 US/Pacific (20 Oct 2026, 12:11 BST)-** Google Cloud Platform services and APIs were made fully available to customers. Some Google Compute Engine virtual machines were still not yet available. * **20 Oct 04:29 US/Pacific (20 Oct 2026, 12:29 BST) -** Regional services and backend compute management systems were fully undrained, marking the end of core platform-level disruption. * **20 Oct 05:08 US/Pacific (20 Oct 2026, 13:08 BST) - Majority Workload Recovery-** GCE virtual machines were 99.5% operational and healthy, and creating new VMs was fully supported. Service availability was restored for most customer workloads, with resolution confirmed for the majority of users across Google Cloud Platform services in the region. Following the recovery of a small tail of remaining isolated workloads, the closure notification for the incident was posted by 07:03 US/Pacific (20 Oct 2026, 15:03 BST). Google is committed to preventing a repeat of this issue in the future and is completing the following actions: **Data Center Action Items:** * Restoration of normal utility configuration (both A & B feeds) * Utility provider to locate the damaged cable fault, using low-frequency radar penetration testing procedures. **[Completed 26 Oct]** * Utility provider to repair the cable, test and restore the impacted primary utility feed A source. **[Estimated Completion Date 13 Nov]** * Onsite Operations teams with a controlled method of procedure (MOP) to transfer the facility to its primary utility source (feeds A and B) from standby utility feed through coordinated switching with the utility provider **[Estimated Completion Date 17 Nov]** * Generator confidence testing * Full generator load transfer tests with utility power cutover of the active utility feed. Test automatic startup of generators through PLC signals within the backup battery timer and detailed review of backup procedures **[Completed on 20 Oct and 26 Oct (full critical load transfer test including updated EOPs)]** * Full generator load transfer tests in coordination with the primary utility source feeds (A and B) after restoration work completed by the primary utility provider. **[Estimated Completion Date 17 Nov]** * PLC configuration fix * Reconfigured and validated the PLC after the outage on 20 Oct and then again on 26 Oct **[Completed 26 Oct]** * Google engineers to work in collaboration with the facility vendor teams to perform a comprehensive PLC code review and system resiliency to multiple failure scenarios. **[Estimated Completion Date (prior to generator transfer test) 06 Nov]** * Validate PLC telemetry once primary utility feed A and B lineup is restored. **[Estimated Completion Date 17 Nov]** * Validate global PLC configurations at sites with similar topologies and PLC manufacturers **[Estimated Completion Date 15 Nov]** * Emergency Operating Procedures (EOP) documentation update: * Comprehensive update to the EOP for site’s response to unexpected loss of active utility source. Update includes - manual steps to attempt to restore active utility feed, manual restart of generators and manual transfer to other utility sources within the UPS battery run time. **[Completed 26 Oct]** * Ensure updated EOP is practiced twice per shift by on-site facility team. **[Completed 24 Oct and checked with Google DC Operations daily]** * Detect and prevent future PLC misconfigurations * Google to ensure PLC code reviews are fully conducted and validated during facility commissioning and Integrated System Tests (ISTs) prior to Facility Ready (FR). A second Google team will then validate this within a quarter post-FR. **[Estimated Completion Date 18 Dec]** * Strengthen change management: * Freeze planned maintenance activities at other sites with similar topologies, and implement elevated approvals and reviews for data center configuration changes which are outside their standard designs. **[Completed Date 30 Oct]** **Cloud Service Action Items:** * **Communications Enhancement:** Bolster notification speed by developing an automated alert-to-communication mechanism for location-impacting incidents. * **Platform Testing:** Expand platform-wide testing outcomes for infrastructure-level events. ## Detailed Description of Impact Between Monday, 19 Oct 2026, 23:00 US/Pacific (Tuesday, 20 Oct 2026, 07:00 BST) and Tuesday, 20 Oct 2026, 05:08 US/Pacific (Tuesday, 20 Oct 2026, 13:08 BST), customers utilizing Google Cloud Platform services in the europe-west2 region experienced service disruptions across two consecutive phases, lasting a total duration of 6 hours, 08 minutes. During the initial phase from 23:00 US/Pacific (07:00 BST) to 04:29 US/Pacific (12:29 BST) (duration 5 hours, 29 minutes), customers experienced unavailability of zone-scoped resources in products, including: * **Compute Engine** - VM instances, zonal MIGs, unmanaged instance groups, zonal NEGs, sole-tenant node groups, zonal reservations, target instances, zonal API operations. * **Persistent Disk / Hyperdisk** - Zonal PD, zonal Hyperdisk, Hyperdisk storage pools, instant snapshots. * **GKE -** Zonal clusters (control plane), node pool nodes in -b, PVs on zonal disks. * **Cloud SQL -** Non-HA instances, read replicas in -b. * **AlloyDB -** Basic (non-HA) primaries in -b. * **Bigtable -** Single-cluster instances in -b. * **Other products with affected zonal resources:** Cloud Batch, Cloud Build, Cloud Storage, Cloud Workstations, Composer, Dataproc, Filestore, Managed Lustre, Migrate to VMs, NetApp Volumes, Pub/Sub Lite, Vertex AI Workbench, VMware Engine. The unavailability of those resources scoped to a zone that undergoes disruption is working within the design of a zonally-scoped system. Requests made to these resulted either in a timeout or error code during the disruption. Workloads and resources hosted entirely within europe-west2-b became unreachable due to this event. While the physical power outage was isolated strictly to data center facilities in zone europe-west2-b, some customers running workloads in unimpacted zones (europe-west2-a and europe-west2-c) or across regional architectures also experienced unexpected impact. Google Cloud designs regional services to be robust to zone failures, but in this case there were a set of unexpected failures which caused impact outside of the zonal failure domain. We are committed to learning from this incident and preventing zonal events from impacting broader regional operations. The primary causes of impact outside of zone europe-west2-b were: 1) Instantaneous demand surges on neighboring zones (a and c) and 2) Control-plane dependencies across zonal boundaries See below for more detailed descriptions of impact and next steps for each impacted product. ### Google Compute Engine and Persistent Disk **Impact:** Upon power loss in europe-west2-b at 22:53 US/Pacific (06:53 BST), all Compute Engine VMs and zonal Persistent Disk and Hyperdisk volumes in the zone became unavailable. Google Compute Engine's zonal resources, such as VMs, require customers to provision cross-zone failover and recovery mechanisms tailored to their needs. During this incident, however, some of these failover attempts were unsuccessful due to capacity constraints and difficulty in replicating the underlying storage mechanism. Once data hall power was restored at 00:20 US/Pacific (08:20 BST), engineers worked to confirm storage integrity before restoring compute services. Following platform service restoration, some customer workloads running on Compute Engine instances as well as products that rely on Compute Engine experienced a longer recovery due to action taken by responders in order to prevent data loss. Once storage stabilized, engineers brought VMs and zonal disks in the zone back online between 04:01 US/Pacific (12:01 BST) and 04:29 US/Pacific (12:29 BST). By 04:46 US/Pacific (12:46 BST) new VM creation resumed, and by 05:08 US/Pacific (13:08 BST) over 99% of Compute Engine VM were in a healthy state. (The remaining VMs were restarted after their disks recovered). Any remaining customers that were experiencing VM problems were directed to file a customer support case as per normal procedure. **Next Steps:** Google Compute Engine and Persistent Disk engineering teams are conducting a comprehensive postmortem review of this event along with Google data center and infrastructure teams. The follow-up actions focus on preventing a recurrence and on making our clusters recover from an unplanned power loss more quickly and safely. We are also expanding our regular disaster-recovery testing for full cluster power-loss scenarios to validate end-to-end Compute Engine recovery. The zonal failure in a facility within europe-west2-b exhibited sequencing atypical of previous zonal outages. We are investigating additional signals to incorporate into our failure detection capabilities for Regional Persistent Disk, so that should this sequence recur, Regional Persistent Disk can differentiate this case from the more typical zonal outage scenarios. We exercise caution with all changes to detection mechanisms to ensure we do not regress our capabilities to detect and react to more typical outages. ### Cloud SQL **Impact:** Upon power loss, Cloud SQL detected failures and immediately initiated automated failovers for all regional HA instances. The failover was complete for regional instances that did not have Regional Persistent Disk failures (see above), mitigating their impact right away. A majority of the remaining instances recovered by 20 Oct 2026, 01:00 US/Pacific (09:00 BST) once the Regional Persistent Disk recovered, shortly after europe-west2-b recovery. A small number of remaining instances were fully recovered by 20 Oct 2026, 11:00 US/Pacific (19:00 BST). **Next Steps:** Our engineering team is implementing improvements across our database and storage infrastructure to ensure that High Availability instances using Regional Persistent Disks recover more rapidly during unplanned outages. ### Google Kubernetes Engine **Impact:** The power loss in europe-west2-b caused total zonal failure, autoscaling stalls, API error spikes, and regional pod unavailability across GKE clusters. Total incident duration for GKE was 7 hours and 34 minutes, starting at 23:02 US/Pacific (07:02 BST), reaching initial mitigation at 05:22 US/Pacific (13:22 BST), and achieving final resolution at 06:37 US/Pacific (14:37 BST). Zonal clusters in europe-west2-b experienced 100% unavailability between 23:05 US/Pacific (07:05 BST) and 04:30 US/Pacific (12:30 BST), with full restoration by 06:00 US/Pacific (14:00 BST). Regional clusters lost worker nodes in europe-west2-b, causing a spike in regional unavailable pods. Worker nodes scaled up in neighboring zones europe-west2-a and europe-west2-c. The scale ups in surviving zones were impacted by available capacity. Autoscaling was slowed down due to increased load and failures of underlying APIs, such as Google Compute Engine (see above). Regional API operations suffered increased failure rates for cluster creation, deletion, updates and node pool operations due to reduced capacity and increased load on underlying APIs (see above). ### Google Cloud Dataflow **Impact:** Dataflow mostly behaved as expected for a zonal failure: new batch jobs were automatically routed away from europe-west2-b within about one minute, and all workloads (streaming and batch) recovered with no data loss once power returned. Jobs running in the affected zone also resumed responding to user cancellation requests once the zone came back up. Additionally, we identified and have now fixed an issue that caused increased streaming job start latency for about two hours. Google engineering is actively working to resolve a zone-selection issue that incorrectly routed a small number of new jobs to the unavailable zone. ### Looker **Impact:** The power event interrupted Looker's connectivity to GKE and CloudSQL, which Looker uses for its backend compute and metadata database resources, respectively. About 45% of instances became unresponsive as Looker's messaging middle tier was unable to recover and reestablish database connectivity due to degraded GKE and Cloud SQL availability. A manual rolling restart of messaging infrastructure across all instances brought unavailable Looker instances down to about 15% within about two hours of onset. Subsequently, regional control-plane issues in GKE pushed instance unavailability back to about 35% before settling near 20% for several hours. Cloud SQL failover degradation extended the delay as well. Availability returned to pre-incident baseline by 05:20 US/Pacific (13:20 BST) as the GKE outage was mitigated; the incident was declared mitigated at 07:44 US/Pacific (15:44 BST). **Next Steps**: Engineering teams are working to expand zonal outage telemetry and improve Looker's messaging middleware failovers to shorten recovery times during zonal unavailability. ### AlloyDB **Impact:** Customer impact for AlloyDB began at 23:07 US/Pacific (07:07 BST). Regional primary AlloyDB instances experienced up to a 95-minute delay in starting automated failovers due to delayed failover notifications. ~4% of these instances experienced a stalled failover due to Persistent Disk issues that required manual recovery. Additionally, zonal primary instances, zonal secondary instances, and single-node read pool instances encountered downtime directly aligned with the zone's power loss. Over 99% of affected AlloyDB instances in the region were restored to a healthy state by 06:16 US/Pacific (14:16 BST), with the final zonal primary AlloyDB instances recovering by 08:28 US/Pacific (16:28 BST). **Next Steps:** AlloyDB engineering team will be updating their monitoring system to detect zonal outage reliably and send the failover notification. The AlloyDB team is also partnering with the Persistent Disk team to ensure that high availability instances which leverage regional disk will recover faster during unplanned downtime events. ### BigQuery **Impact:** BigQuery experienced a service disruption in the europe-west2 region between 23:03 US/Pacific (07:03 BST) and 04:12 US/Pacific (12:12 BST) (approximately 5 hours and 9 minutes). During this incident, affected customers experienced significant increases in job latencies and high query queuing, resulting in delayed job execution. Customers also experienced intermittent 503 UNAVAILABLE errors on Job API calls (InsertJob, GetQueryResult). Similarly, customers received errors when calling AppendRows on buffered-type streams also after the incident onset until the streams were re-created. Finally, customers experienced reduced processing efficiency and elevated job failure rates across affected projects. The majority of the impact was confined to customers assigned to the impacted zone and was caused by an autoscaling dependency in a critical data plane job, which was unable to scale up during the failover. Some customers not assigned to the impacted zone saw elevated (1%) error rates on JobAPI calls due to overly broad concurrency throttling in the Job API component. **Next Steps:** Engineering teams have updated job provisioning to eliminate the dependency on autoscaling and are enhancing isolation mechanisms for the job server to ensure that future zonal disruptions are contained. ### Memorystore Redis **Impact:** During the power disruption, Basic Tier (non-HA) instances located in europe-west2-b experienced full unavailability, while Standard Tier (HA) instances initiated automated failovers or operated in a degraded state with missing replicas. Following the restoration of the zone, a subset of instances remained stuck in a REPAIRING state. For these affected instances, the data plane remained fully available and online for customer use, but control plane operations such as scaling and RDB exports were temporarily blocked. Google engineers manually mitigated this issue and fully repaired all affected instances within 24 hours. **Next Steps:** The team is working on mechanisms to detect cases when the control plane and data plane get out of sync, then reconcile them so that the system can automatically recover. ### Apigee X **Impact:** During the power disruption, the Apigee X runtime in the region returned elevated HTTP 5xx errors for 7 hours and 19 minutes. Apigee X is **designed to withstand** a single-zone loss as its datastore keeps replicas across the region's three zones, but a scheduling misconfiguration had placed two of three replicas in the zone that lost power, so the datastore lost quorum and the runtime failed requests instead of failing over. The errors were concentrated in a small number of affected clusters rather than spread across the region. As remediation, engineers restored the affected replicas into nearby zones. Apigee Hybrid clusters were not severely impacted. **Next Steps:** The engineering team has already audited the Apigee fleet to rebalance unevenly spread instances without downtime, and added monitoring to alert if datastore replicas drift across zones. Moving forward, the team will modify Apigee X to strictly enforce that every instance's three datastore replicas always run in three different zones. Additionally, the team is improving alert handling practices to help engineers better focus on affected services during similar outages. ### Apigee Edge **Impact:** During the power disruption, Apigee Edge clusters that had a single node in the affected zone successfully auto-recovered once power was restored. However, clusters with multiple nodes in the affected zone experienced extended recovery times. The automated node replacement system didn't handle multiple nodes going down simultaneously. This required manual intervention by Google engineers to restore the affected nodes. Furthermore, during this manual recovery, some virtual machines experienced a timeout when attempting to reach external OS repositories, causing them to boot with an older binary version and further delaying full restoration. **Next Steps:** The engineering team will implement retries and scope repository updates to prevent pre-hook timeouts when reaching external OS repositories during the boot process. The team is also investigating further multiple-node failure scenario resilience improvements. ### Cloud Bigtable **Impact:** Cloud Bigtable behaved as expected during the europe-west2-b power outage. All single-cluster instances located in europe-west2-b experienced expected zonal unavailability while the zone lost power and recovered. Multi-cluster instances configured with High Availability (HA) routing automatically failed over to healthy replica clusters in other zones where replica clusters and the control plane remained available with sufficient capacity to absorb the failover load. ### List of impacted services We did not identify any impact of the outage outside of the europe-west2 region. The following Google Cloud Platform services experienced impact within europe-west2: * AlloyDB for PostgreSQL * Apigee * BigQuery Data Transfer Service * Cloud Data Fusion * Cloud Filestore * Cloud Firestore * Cloud Load Balancing * Cloud Memorystore * Cloud NAT * Cloud Run * Cloud Spanner * Cloud Workstations * Datastream * Dialogflow CX * Google App Engine * Google BigQuery * Google Cloud Bigtable * Google Cloud Dataflow * Google Cloud Dataproc * Google Cloud NetApp Volumes * Google Cloud Pub/Sub * Google Cloud SQL * Google Cloud Storage (GCS) * Google Compute Engine (GCE) * Google Kubernetes Engine (GKE) * Google SecOps (Security Information and Event Management [SIEM] and Security Orchestration, Automation, and Response [SOAR]) * Looker (Google Cloud core) * Looker Studio * Managed Airflow (Google Cloud Composer) * Managed Service for Apache Kafka * Memorystore for Memcached * Memorystore for Redis * Memorystore for Redis Cluster * Memorystore for Valkey * Network Connectivity Center * Persistent Disk * Private Service Connect * Speech-to-Text * Virtual Private Cloud (VPC) * VMware Engine --- [2026-10-27T15:13:38+00:00] (AVAILABLE) ## Incident Report ### **Summary** On Monday, 19 Oct 2026 (Tuesday, 20 Oct BST), a data center facility that hosts europe-west2-b, experienced an external electrical power disruption. This resulted in service unavailability for workloads located in this zone. As traffic was redirected to alternative cloud regions or unaffected zones within europe-west2 cloud region, these workloads experienced transient latency and elevated errors affecting services across europe-west2.  The primary impact was mitigated after 6 hours 8 minutes. ### **Root Cause** **Facility architecture and background:** The data center facility in the UK region hosts Cloud clusters serving the europe-west2-b zone, which form part of the multi-zonal europe-west2 Cloud region. The site relies on a 2N utility power architecture—meaning the facility has complete duplicate power paths for every critical load—backed by a central high-voltage generator bank managed by a dual-redundant Programmable Logic Controller (PLC). Primary utility power is supplied to the facility via two independent feeders (A and B), supplemented by a standby utility connection configured for manual campus-wide transfer during maintenance operations or emergency events. The two high-voltage primary feeders terminate at separate primary intake switchboards capable of closed-loop operation if either board is taken offline. Switching between the primary and standby utility providers utilizes open transitions and key interlocks to prevent parallel connections across sources. Static Uninterruptible Power Supply (UPS) battery systems provide 5 minutes of autonomous runtime. This bridge power ensures uninterrupted operation while the PLC detects utility undervoltage events, initiates diesel generator startup, synchronizes the generators, and transfers the site load. Prior to the utility disruption, the facility had been placed in a temporary single-feed (1N) bridged maintenance posture on the primary utility. Circuit breaker feeder B was physically opened and key-interlocked (Locked Out Tagged Out) to allow for corrective repairs following issues identified during a quarterly generator load test on 14 Oct 2026. Consequently, primary utility feed A was supporting the total critical load while repairs were conducted on the B feeder pathway. **Root Cause:** On Monday, 19 Oct 2026 at 22:53 US/Pacific (Tuesday, 20 Oct 06:53 BST), the primary utility provider experienced an outage on primary utility feed A, caused by an external underground cable fault on the utility network outside the data center facility.   When the primary utility feed A was lost, the facility’s generator plant failed to receive a signal to automatically start and take critical load due to a design voltage-sensing and misconfiguration in the PLCs. The facility's static UPS battery banks carried the critical load as designed until their battery reserves depleted resulting in a complete power loss across data halls. The investigation of the PLC configuration identified the root cause as a misconfiguration of the PLC logic that did not verify both an undervoltage condition and physical breaker position for both utility feeders. Instead, the PLC undervoltage sensing inputs were wired upstream (line side) of the isolated utility feed B breaker. The PLC was programmed to verify whether voltage was present on the feeder before commanding a generator start. As the utility feed B remained energized upstream, both PLCs sensed live upstream voltage on the disconnected path. As a result, the PLC logic indicated that a healthy utility source was available, even though the primary and secondary distribution feeds were de-energized, and did not issue a start command to the generator plant.; The onsite facilities team attempted to execute a remote load transfer via the PLC; however, the system inhibited the action. Recognizing that the UPS battery reserves would be exhausted before further remote operations could be resolved, the team transferred the facility load to the standby utility source, restoring the critical load that was lost once batteries depleted during this process. Once utility power was restored via the standby utility source, and UPS batteries started recharging, the onsite facility teams and OEM vendors reconfigured and validated PLC functionality on both undervoltage and breaker status. After the power loss was initially detected, Google engineers began work to mitigate failover failures and prepare service recovery. Upon restoration of the utility source, UPS and generator capabilities, they began the process to re-enable services in europe-west2-b. ### Remediation and Prevention The sequence of events leading to customer impact was as follows: * **19 Oct 22:53 US/Pacific (20 Oct BST 06:53 BST) -** An electrical power disruption occurred at the data center facility hosting availability zone europe-west2-b, and a PLC (Programmable Logic Controller) startup fault prevented facility emergency generators from assuming the electrical load. Facility load continued to be supported by UPS battery banks until the batteries were depleted. * **19 Oct 23:00 US/Pacific (20 Oct 07:00 BST)** **Impact start -** As battery backups were exhausted, physical host servers, local storage infrastructure, and network aggregation hardware in availability zone europe-west2-b lost power, causing instances, database replicas, and worker nodes in that zone to become immediately unreachable. * **19 Oct 23:04 US/Pacific (20 Oct 07:04 BST) -** Google engineers were alerted to the disruption via automated monitoring systems and probers, which detected elevated API error ratios, job submission timeouts, and loss of infrastructure reachability in zone europe-west2-b. Engineering teams immediately mobilized to isolate the affected infrastructure and commence recovery. * **19 Oct 23:09 US/Pacific (20 Oct 07:09 BST) -** Regional traffic-routing mechanisms and client applications initiated automated failover toward available infrastructure in adjacent availability zones within the region. * Cross-zone remote procedure calls from regional service control planes directed to metadata and catalog components in the offline zone encountered timeouts, causing initial job submission stalls and API latency spikes. * The sudden influx of redirected query executions, high-availability database failovers, and compute workloads saturated available compute slots and processing capacity in other availability zones, creating elevated admission queues, delayed database failover completions, and intermittent 500 and 503 API errors across the region. * **Traffic Isolation:** Google engineers isolated the offline availability zone (europe-west2-b) by adjusting regional service routing away from the affected infrastructure, preventing cross-zone client requests from timing out against offline endpoints. * **Workload Reprioritization and Resource Safeguards:** Engineers adjusted scheduler allocations and capacity limits across unimpacted infrastructure to prioritize active customer reservations, reduce resource contention on execution slots, and relieve queue backlogs for regional workloads. * **19 Oct 23:54 US/Pacific (20 Oct 07:54 BST) Utility Power Restoration** **\-** Power supply from the standby utility source was restored and power restoration to the data hall began. * **20 Oct 00:20 US/Pacific (08:20 BST) Datahall Power Restoration** **\-** Utility power was re-established to the datahalls. Mains utility power normalized; power feed to data hall verified. Following this, the site operations and engineering teams focused on and completed a reset and tested the emergency backup generator automation controllers to restore facility power. * **20 Oct 00:40 US/Pacific (08:40 BST)** **\-** Clusters began to recover, cluster manager systems started rescheduling compute jobs.  * **20 Oct 00:45 US/Pacific (08:45 BST) \-** Network devices were back online.  * **20 Oct 00:50 US/Pacific (08:50 BST) \-** Due to the immediacy of power loss, storage devices with unclean shutdowns began recovery. Responders recognized this and chose not to restore services that would otherwise make this worse. Because of the large volume of storage devices involved, this process required a substantial period to finish prior to restoring service to customers. * **20 Oct 03:13 US/Pacific (11:06 BST)** **\-** Power redundancy was verified and the storage infrastructure was sufficiently restored to prepare the initiation of controlled traffic re-admission. The remaining storage systems continued recovery operations. * **20 Oct 03:45 US/Pacific (11:45 BST) Controlled Traffic Re-admission** **\-** Once system health and storage integrity were verified, engineers executed gradual, controlled traffic re-admission back to zone europe-west2-b allowing accumulated job backlogs to clear smoothly. * **20 Oct 04:11 US/Pacific (12:11 BST)** **\-** Google Cloud Platform services and APIs were made fully available to customers. Some Google Compute Engine virtual machines were still not yet available. * **20 Oct 04:29 US/Pacific (12:29 BST) \-** Regional services and backend compute management systems were fully undrained, marking the end of core platform-level disruption. * **20 Oct 05:08 US/Pacific (13:08 BST) Majority Workload Recovery** **\-** GCE virtual machines were 99.5% operational and healthy, and creating new VMs was fully supported. Service availability was restored for most customer workloads, with resolution confirmed for the majority of users across Google Cloud Platform services in the region. Following the recovery of a small tail of remaining isolated workloads, the closure notification for the incident was posted by 07:03 US/Pacific (15:03 BST). Google is committed to preventing a repeat of this issue in the future and is completing the following actions: **Data Center Action Items:** * Restoration of normal utility configuration (both A & B feeds) * Utility provider to locate the damaged cable fault, using low-frequency radar penetration testing procedures. **\[Completed 26 Oct\]** * Utility provider to send on-site engineers to repair the cable fault and restore the impacted primary utility feed A source. **\[Estimated Completion Date 30 Oct\]** * Onsite Operations teams with a controlled method of procedure (MOP) to transfer the facility to its primary utility source (feeds A and B) from standby utility feed through coordinated switching with the utility provider **\[Estimated Completion Date 31 Oct\]** * Generator confidence testing * Full generator load transfer tests with utility power cutover of the active utility feed. Test automatic startup of generators through PLC signals within the backup battery timer and detailed review of backup procedures **\[Completed on 20 Oct and 26 Oct (full critical load transfer test including updated EOPs)\]** * Full generator load transfer tests in coordination with the primary utility source feeds (A and B) after restoration work completed by the primary utility provider. **\[Estimated Completion Date 31 Oct\]** * PLC configuration fix  * Reconfigured and validated the PLC after the outage on 20 Oct and then again on 26 Oct **\[Completed 26 Oct\]** * Google engineers to work in collaboration with the facility vendor teams to perform a comprehensive PLC code review and system resiliency to multiple failure scenarios. **\[Estimated Completion Date (prior to generator transfer test) estimated 31 Oct\]** * Validate PLC telemetry once primary utility feed A and B lineup is restored. **\[Estimated Completion Date 31 Oct\]** * Validate global PLC configurations at all global sites with similar topologies and PLC manufacturers, to ensure confidence in automatic generator starts. **\[Estimated Completion Date 15 Nov\]** * Emergency Operating Procedures (EOP) documentation update: * Comprehensive update to the EOP for site’s response to unexpected loss of active utility source. Update includes \- manual steps to attempt to restore active utility feed, manual restart of generators and manual transfer to other utility sources within the UPS battery run time. **\[Completed 26 Oct\]** * Ensure updated EOP is practiced twice per shift by on-site facility team. **\[Completed 24 Oct and checked with Google DC Operations daily\]** * Strengthen change management:  * Freeze planned maintenance activities at other sites with similar topologies, and implement elevated approvals and reviews for data center configuration changes which are outside their standard designs. **\[Estimated Completion Date 30 Oct\]** **Cloud Service Action Items:** * **Communications Enhancement:** Bolster notification speed by developing an automated alert-to-communication mechanism for location-impacting incidents. * **Platform Testing:** Expand platform-wide testing outcomes for infrastructure-level events. ### **Detailed Description of Impact** Between Monday, 19 Oct 2026, 23:00 US/Pacific (Tuesday, 20 Oct 2026, 07:00 BST) and Tuesday, 20 Oct 2026, 05:08 US/Pacific (13:08 BST), customers utilizing Google Cloud Platform services in the europe-west2 region experienced service disruptions across two consecutive phases, lasting a total duration of 6 hours, 08 minutes. During the initial phase from 23:00 to 04:29 US/Pacific (07:00 to 12:29 BST) (duration 5 hours, 29 minutes), customers experienced unavailability of zone-scoped resources in products, including: * **Compute Engine** \- VM instances, zonal MIGs, unmanaged instance groups, zonal NEGs, sole-tenant node groups, zonal reservations, target instances, zonal API operations.  * **Persistent Disk / Hyperdisk** \- Zonal PD, zonal Hyperdisk, Hyperdisk storage pools, instant snapshots. * **GKE \-** Zonal clusters (control plane), node pool nodes in \-b, PVs on zonal disks. * **Cloud SQL \-** Non-HA instances, read replicas in \-b. * **AlloyDB \-** Basic (non-HA) primaries in \-b. * **Bigtable \-** Single-cluster instances in \-b. * **Other products with affected zonal resources:** Cloud Batch, Cloud Build, Cloud Storage, Cloud Workstations, Composer, Dataproc, Filestore, Managed Lustre, Migrate to VMs, NetApp Volumes, Pub/Sub Lite, Vertex AI Workbench, VMware Engine. The unavailability of those resources scoped to a zone that undergoes disruption is working within the design of a zonally-scoped system. Requests made to these resulted either in a timeout or error code during the disruption. Any workloads and resources hosted entirely within europe-west2-b became unreachable due to this event. Google Compute Engine's zonal resources such as VMs require customers to provision failover or cross-zone recovery resources if needed, and to set up a recovery mechanism that matches their needs. Some failovers were unsuccessful due to capacity constraints and difficulty in replicating the underlying storage mechanism.  Following platform service restoration, some customer workloads running on Compute Engine instances as well as products that rely on Compute Engine experienced a longer recovery. By 04:46 US/Pacific (12:46 BST) new Virtual Machine creation resumed and by 05:08 US/Pacific (13:08 BST) over 99% of Compute Engine Virtual Machines were in a healthy state. Any remaining customers that were experiencing Virtual Machine problems were directed to file a customer support case as per normal procedure. While the physical power outage was isolated strictly to data center facilities in zone europe-west2-b, some customers running workloads in unimpacted zones (europe-west2-a and europe-west2-c) or across regional architectures also experienced unexpected impact. The primary causes of impact outside of zone europe-west2-b were: 1\) Instantaneous demand surges on neighboring zones (a and c) and 2\) Control-plane dependencies across zonal boundaries Affected products included: AlloyDB, Apigee Infra and Apigee Edge, BigQuery, Cloud Dataflow, Cloud Pub/Sub, Cloud SQL, Google Compute Engine, Google Kubernetes Engine, Looker, Regional Persistent Disk, Vertex AI Prediction, and Cloud Speech-to-Text. These services experienced unexpected degradation and failover issues driven by sudden compute capacity exhaustion from surging demand, and control-plane API timeouts. Customers would have experienced the inability to create, update, or delete some regional resources during this period. This was not a full regional control-plane outage, but certainly a degraded state. Multi-zonal and regional services that spanned across the europe-west2 region experienced elevated latency, transient API errors (such as HTTP 500 and 503 errors), and task admission queuing as failover traffic concentrated onto unimpacted regional resources and cross-zone calls to offline components timed out.  Storage write operations in the region experienced a transient error rate during the initial failover period, and regional query admission queues temporarily peaked before rapidly subsiding as capacity re-balanced. We did not identify any impact of the outage outside of the europe-west2 region. The following Google Cloud Platform services experienced impact within europe-west2: * AlloyDB for PostgreSQL * Apigee * BigQuery Data Transfer Service * Cloud Data Fusion * Cloud Filestore * Cloud Firestore * Cloud Load Balancing * Cloud Memorystore * Cloud NAT * Cloud Run * Cloud Spanner * Cloud Workstations * Datastream * Dialogflow CX * Google App Engine * Google BigQuery * Google Cloud Bigtable * Google Cloud Dataflow * Google Cloud Dataproc * Google Cloud NetApp Volumes * Google Cloud Pub/Sub * Google Cloud SQL * Google Cloud Storage (GCS) * Google Compute Engine (GCE) * Google Kubernetes Engine (GKE) * Google SecOps (Security Information and Event Management \[SIEM\] and Security Orchestration, Automation, and Response \[SOAR\]) * Looker (Google Cloud core) * Looker Studio * Managed Airflow (Google Cloud Composer) * Managed Service for Apache Kafka * Memorystore for Memcached * Memorystore for Redis * Memorystore for Redis Cluster * Memorystore for Valkey * Network Connectivity Center * Persistent Disk * Private Service Connect * Speech-to-Text * Virtual Private Cloud (VPC) * VMWare engine ---------- --- [2026-10-22T08:42:46+00:00] (AVAILABLE) ## Preliminary Incident Report We recognize that Google Cloud services are critical to your organization, and we sincerely apologize for the disruption this incident may have caused to your business. We are working to address the root cause and prevent this from occurring in the future. Please note, this information is based on our best knowledge at the time of posting and is subject to change as our investigation continues. A final Incident Report with preventative actions will be posted once our investigation is complete. If you have experienced impact outside of what is listed below, please reach out to Google Cloud Support using [**https\://cloud.google.com/support**](https://cloud.google.com/support). ## Date/Time of the Issue Incident Start:19 Oct 2026 23:00 US/Pacific / 20 Oct 2026 07:00 BST Incident End: 20 Oct 2026 05:10 US/Pacific / 20 Oct 2026 13:10 BST Duration: 6 hours, 10 minutes ## Summary On Monday, 19 October 2026 (Tuesday, 20 October BST), multiple Google Cloud Platform services in the europe-west2 region experienced service disruptions, elevated error rates, Application Programming Interface (API) timeouts, and processing latency for a duration of 6 hours and 10 minutes. The disruption was triggered by an electrical power interruption at the datacenter facility hosting availability zone europe-west2-b, which temporarily took physical host servers, network routing hardware, and storage systems offline. This subsequently caused secondary failover and queuing delays across unimpacted regional infrastructure.  ## Preliminary Root Cause The incident was triggered when a power grid disruption occurred at the datacenter facility hosting availability zone europe-west2-b. To maintain continuous power during the disruption, automatic transfer to facility backup power systems was triggered immediately. The facility load was transferred to the Uninterruptible Power Supply (UPS) battery banks during the start up sequence of on-site emergency diesel generators. The Programmable Logic Controller (PLC) automation system (both primary and backup PLCs) failed to initiate the logical automatic start/transfer operations of the generators, preventing backup generators from assuming the load. When UPS battery reserves were depleted, physical host servers, network switching fabric, and local storage arrays dedicated to europe-west2-b lost power and went offline. The sequence of events leading to customer impact was as follows: * At 22:53 US/Pacific (20 Oct, 06:53 BST), an electrical power disruption occurred at the datacenter facility hosting availability zone europe-west2-b, and a PLC (Programmable Logic Controller) startup fault prevented facility emergency generators from assuming the electrical load. Facility load continued to be supported by UPS battery banks until the batteries were depleted, starting at 23:00 US/Pacific (20 Oct, 07:00 BST). * When the physical host servers, local storage infrastructure, and network aggregation hardware in europe-west2-b lost power, it caused instances, database replicas, and worker nodes in that zone to become immediately unreachable. * Regional traffic-routing mechanisms and client applications initiated automated failover toward available infrastructure in adjacent availability zones within the region. * Cross-zone remote procedure calls from regional service control planes directed to metadata and catalog components in the offline zone encountered timeouts, causing initial job submission stalls and API latency spikes. * The sudden influx of redirected query executions, high-availability database failovers, and compute workloads saturated available compute slots and processing capacity in other availability zones, creating elevated admission queues, delayed database failover completions, and intermittent 500 and 503 API errors across the region. Google engineers have begun a full root cause analysis (RCA) and will provide additional information once it is available. ## Remediation Google engineers were alerted to the disruption via automated monitoring systems and probers at 23:08 US/Pacific on 19 Oct (20 Oct, 07:08 BST), which detected elevated API error ratios, job submission timeouts, and loss of infrastructure reachability in europe-west2-b. Engineering teams immediately mobilized to isolate the affected infrastructure and commence recovery: * **Traffic Isolation:** Google engineers isolated the offline availability zone (europe-west2-b) by adjusting regional service routing away from the affected infrastructure, preventing cross-zone client requests from timing out against offline endpoints. * **Workload Reprioritization and Resource Safeguards:** Engineers adjusted scheduler allocations and capacity limits across unimpacted infrastructure to prioritize active customer reservations, reduce resource contention on execution slots, and relieve queue backlogs for regional workloads. * **Power Grid Restoration:** On-site facility engineers conducted graceful restoration of a stable utility power feed once utility supply was back, within 1 hour. Following this, they focused and completed a reset and tested the emergency backup generator automation controllers to restore facility power. * **Progressive Infrastructure Re-activation:** Google engineers systematically restarted core Google Cloud infrastructure and services. * **Controlled Traffic Re-admission:** Once system health and storage integrity were verified, engineers executed gradual, controlled traffic re-admission back to zone europe-west2-b allowing accumulated job backlogs to clear smoothly. By 05:10 US/Pacific on Tuesday, 20 Oct(13:10 BST), service availability had recovered for the vast majority of customer workloads, and resolution for most of the customers across Google Cloud Platform services in the region was confirmed. Following the recovery of a small tail of remaining isolated workloads, the closure notification for the incident was posted by 07:03 US/Pacific (15:03 BST). ## Description of Impact Between Monday, 19 Oct 2026, 23:00 US/Pacific (Tuesday, 20 Oct 2026, 07:00 BST) and Tuesday, 20 October 2026, 05:10 US/Pacific (13:10 BST), customers utilizing Google Cloud Platform services in the europe-west2 region experienced service disruptions across two consecutive phases, lasting a total duration of 6 hours, 10 minutes. During the initial phase from 23:00 to 04:29 US/Pacific (07:00 to 12:29 BST) (duration 5 hours, 29 minutes), customers experienced elevated error rates, API timeouts, and processing delays until most Google Cloud Platform services recovered. Following platform service restoration, some customer workloads running on Compute Engine instances experienced a longer recovery tail. By 04:46 US/Pacific (12:46 BST) new Virtual Machine creation resumed and by 05:10 US/Pacific (13:10 BST) over 99% of Compute Engine Virtual Machines were in a healthy state. Any remaining customers that were experiencing Virtual Machine problems were directed to file a customer support issue as per normal procedure. While the physical power outage was isolated strictly to datacenter facilities in europe-west2-b, some customers running workloads in unimpacted zones (europe-west2-a and europe-west2-c) or across regional architectures also experienced unexpected impact. The primary causes were 1\) instantaneous demand surges on unimpacted compute capacity and 2\) synchronous control-plane validation dependencies across zonal boundaries. Affected products included: BigQuery, Looker, Google Compute Engine, Google Kubernetes Engine, Regional Persistent Disk, and Cloud SQL. These services experienced unexpected degradation and failover issues driven by sudden compute capacity exhaustion from surging demand, and control-plane API timeouts waiting on validations from the offline zone. Workloads and resources hosted entirely within europe-west2-b became unreachable. Data storage services with failover capability such as Cloud SQL, AlloyDB, Memorystore for Redis, and Cloud Bigtable failed over into nearby unimpacted zones during the europe-west2-b outage. Multi-zonal and regional services that spanned across the europe-west2 region experienced elevated latency, transient API errors (such as HTTP 500 and 503 errors), and task admission queuing as failover traffic concentrated onto unimpacted regional resources and cross-zone calls to offline components timed out. Storage write operations in the region experienced a transient error rate during the initial failover period, and regional query admission queues temporarily peaked before rapidly subsiding as capacity re-balanced. The following Google Cloud Platform services experienced impact: * AlloyDB for PostgreSQL * Apigee * BigQuery Data Transfer Service * Cloud Data Fusion * Cloud Filestore * Cloud Firestore * Cloud Load Balancing * Cloud Memorystore * Cloud NAT * Cloud Run * Cloud Spanner * Cloud Workstations * Datastream * Dialogflow CX * Google App Engine * Google BigQuery * Google Cloud Bigtable * Google Cloud Dataflow * Google Cloud Dataproc * Google Cloud NetApp Volumes * Google Cloud Pub/Sub * Google Cloud SQL * Google Cloud Storage (GCS) * Google Compute Engine (GCE) * Google Kubernetes Engine (GKE) * Google SecOps (Security Information and Event Management \[SIEM\] and Security Orchestration, Automation, and Response \[SOAR\]) * Looker (Google Cloud core) * Looker Studio * Managed Airflow (Google Cloud Composer) * Managed Service for Apache Kafka * Memorystore for Memcached * Memorystore for Redis * Memorystore for Redis Cluster * Memorystore for Valkey * Network Connectivity Center * Persistent Disk * Private Service Connect * Speech-to-Text * Virtual Private Cloud (VPC) * VMWare engine --- [2026-10-20T14:03:41+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services were experiencing issues in the europe-west2 region. **Description** The issue with impacted GCP products has been mitigated for most of the customers and it is believed to be affecting currently a very small number of customers and our Engineering Team is working on it. If you have questions or are impacted, please open a case with the Support Team and we will work with you until this issue is resolved. No further updates will be provided here. We will publish an analysis of this incident once we have completed our internal investigation. We thank you for your patience while we're working on resolving the issue. **Symptoms** Google Cloud services were unavailable in europe-west2-b zone; some services in europe-west2 region might experienced elevated errors and intermittent network issues. **Workaround** None as the issue has been mitigated. --- [2026-10-20T12:44:21+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services are experiencing issues in the europe-west2 region. **Description** We are seeing the recovery of services for most workloads in europe-west2 as of Tuesday, 2026-10-20 05:10 PDT. We will provide an update by Tuesday, 2026-10-20 07:00 PDT with current details. We apologize to all who are affected by the disruption. **Symptoms** Google Cloud services are unavailable in europe-west2-b zone; some services in europe-west2 region may experience elevated errors and intermittent network issues. **Workaround** If feasible, the impacted customer may try to migrate their workload impacted to another available location (zone or region). --- [2026-10-20T11:58:15+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services are experiencing issues in the europe-west2 region. **Description** We are experiencing an issue with multiple services in europe-west2 beginning on Monday, 2026-10-19 23:08 PDT. A power event caused an outage within europe-west2-b zone. The power event is mitigated. We are seeing the recovery of services and are prioritizing the recovery of existing workloads.Customers may not be able to yet create new workloads. Full recovery of existing workloads should be completed, tentatively by Tuesday, 2026-10-20 06:00. We will provide an update by Tuesday, 2026-10-20 06:00 PDT with current details. We apologize to all who are affected by the disruption. **Symptoms** Google Cloud services are unavailable in europe-west2-b zone; some services in europe-west2 region may experience elevated errors and intermittent network issues. **Workaround** If feasible, the impacted customer may try to migrate their workload impacted to another available location (zone or region). --- [2026-10-20T11:12:42+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services are experiencing issues in the europe-west2 region. **Description** We are experiencing an issue with multiple services in europe-west2 beginning on Monday, 2026-10-19 23:08 PDT. Due to a power event we had suffered an outage within europe-west2-b zone. The power event is mitigated. Partial mitigation to infrastructure services will be observed within the next 30 minutes and the remaining services will be mitigated there after. We will provide an update by Tuesday, 2026-10-20 05:00 PDT with current details. We apologize to all who are affected by the disruption. **Symptoms** Google Cloud services are unavailable in europe-west2-b zone; some services in europe-west2 region may experience elevated errors and intermittent network issues. **Workaround** If feasible, the impacted customer may try to migrate their workload impacted to another available location (zone or region). --- [2026-10-20T11:00:28+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services are experiencing issues in the europe-west2 region. **Description** We are experiencing an issue with multiple services in europe-west2 beginning on Monday, 2026-10-19 23:08 PDT. Our engineering team continues to investigate the issue. We will provide an update by Tuesday, 2026-10-20 05:00 PDT with current details. We apologize to all who are affected by the disruption. **Symptoms** Multiple Google Cloud services are experiencing elevated errors and intermittent network failures in europe-west2 region. Note: Looker Studio is not impacted by this outage. **Workaround** If feasible, the impacted customer may try to migrate their workload impacted to another available location (zone or region). --- [2026-10-20T09:24:19+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services are experiencing issues in the europe-west2 region. **Description** We are experiencing an issue with multiple services in europe-west2 beginning on Monday, 2026-10-19 23:08 PDT. Our engineering team continues to investigate the issue. We will provide an update by Tuesday, 2026-10-20 04:00 PDT with current details. We apologize to all who are affected by the disruption. **Symptoms** Multiple Google Cloud services are experiencing elevated errors and intermittent network failures in europe-west2 region. Note: Looker Studio is not impacted by this outage. **Workaround** If feasible, the impacted customer may try to migrate their workload impacted to another available location (zone or region). --- [2026-10-20T08:35:37+00:00] (SERVICE_DISRUPTION) **Summary** Multiple services are experiencing issues in the europe-west2 region. **Description** We are experiencing an issue with multiple services in europe-west2 beginning on Monday, 2026-10-19 23:08 PDT. Our engineering team continues to investigate the issue. We will provide an update by Tuesday, 2026-10-20 02:30 PDT with current details. We apologize to all who are affected by the disruption. **Symptoms** Multiple Google Cloud services are experiencing elevated errors and intermittent network failures in europe-west2 region. **Workaround** None for now

## Addendum to Incident Report This addendum extends the Detailed Description of Impact from the previous message. Though only two clusters in a datacenter in us-central1-b and us-central1-f experienced network isolation, a few regional products with a dependency on the affected datacenter were also affected. Between 07:41 and 11:52 US/Pacific on Tuesday, September 1, 2026, the following products were affected: - **Compute Engine VMs**: VMs running in the affected data center lost network connectivity to resources located outside of their datacenter. From a Compute Engine perspective, this incident only affected a subset of VMs in us-central1-b and us-central1-f. - **Zonal and Regional Products Based on Compute Engine** Products with dependencies on VMs in the affected datacenter experienced symptoms like connection timeouts or service unavailability because the underlying VMs lost network connectivity. Examples of products that are based on Compute Engine VMs include: Apigee, Cloud SQL, AlloyDB for PostgreSQL, Dataflow, Cloud Filestore, and Looker. - **Google Kubernetes Engine (GKE)**: GKE clusters whose control plane had dependencies on Compute Engine VMs in the affected clusters experienced errors and timeouts when administrators or nodes attempted to connect to the Kubernetes API server. Consequently, deployments might have been delayed, Kubernetes API operations might have failed, and new nodes might not have registered with the control plane (causing node pool operational delays). - **Cloud Run and App Engine:** Workloads in the us-central1 region experienced elevated serving latency, 5xx aborted request errors, and outbound connectivity degradation. To prevent severe request failures, traffic was diverted to other clusters. Diverting requests to other clusters temporarily caused elevated latency or errors in those clusters.Once the impacted cluster was restored, workload demand for these new backends created a 'thundering herd' of concurrent instance initializations. This sudden surge bypassed warm caches and overwhelmed internal file-serving tiers, extending symptoms until emergency capacity was provisioned. - **Other Google APIs and Services**, in us-central1 or a multi-region that includes us-central1, were affected if they had dependencies on software tasks in the affected clusters and weren't able to use software tasks in an unaffected cluster. Symptoms included connection timeouts or service unavailability. Examples of other Google APIs and services are: Google Cloud Bigtable, BigQuery, Google SecOps SOAR, Cloud Spanner, and Cloud Firestore. For some services, symptoms were limited to temporary latency spikes and service unavailability until workloads shifted to unaffected clusters. - **Private Service Connect**: Clients (in any region) experienced connectivity issues involving PSC endpoints with dependencies in us-central1, in specific circumstances: - PSC endpoints for Google APIs were affected in the same way as noted in the Google APIs and services section. - Producer/consumer PSC endpoints were affected if the producer had load balancers or backend VMs in the affected clusters of us-central1. - **Hybrid Connectivity**: Some Cloud Router, Cloud VPN, and Cloud Interconnect VLAN attachments in us-central1 were affected in specific circumstances: - Cloud Router BGP software tasks for some Cloud Routers in us-central1 experienced a Cloud Router maintenance event if their BGP software tasks were running in the affected clusters. - Cloud VPN tunnel software tasks running in the affected clusters lost network connectivity. This caused some Cloud VPN tunnels in us-central1 to go down until a replacement tunnel task in a different cluster was assigned. - Resources (in any region) sending packets through Cloud Interconnect VLAN attachments in us-central1 might have experienced intermittent connectivity issues in certain situations where network flows weren’t already programmed. - **Envoy-based load balancers and other products**: Load balancers and other products that depended on managed Envoy tasks of a proxy-only subnet in us-central1 experienced increased latency or connectivity issues if enough Envoy tasks were in the affected clusters. The following products were affected: - Regional external application load balancers in us-central1 - Regional internal application load balancers in us-central1 - Cross-region internal application load balancers with proxies in us-central1 - Regional external proxy network load balancers in us-central1 - Regional internal proxy network load balancers in us-central1 - Cross-region internal proxy network load balancers with proxies in us-central1 - Secure Web Proxy in us-central1 --- [2026-09-10T21:20:16+00:00] (AVAILABLE) ## Incident Report ## Summary On Tuesday, 1 September 2026, some customers in us-central1 experienced network service degradation and instance isolation for a duration of 4 hours and 11 minutes. To our customers whose businesses were impacted during this disruption, we sincerely apologize. This is not the level of quality and reliability we strive to offer you, and we are taking immediate steps to improve the platform’s performance and availability. ## Root Cause The event was triggered by the inadvertent physical disconnection of network fiber-optic cables during routine hardware maintenance. A technician was performing a scheduled capacity upgrade on data center routers that support a fraction of capacity in the us-central1-b zone and a small fraction of capacity in the us-central1-f zone. During the hands-on maintenance, optical fibers connecting the data center routers to the network fabric were unplugged and the optical transceivers were replaced with a transceiver that supports higher-density connectivity. This transceiver was not compatible with the transceivers still in place in the data center fabric, causing a loss of connectivity for each fiber. The network is designed with redundant routers in separate data center rooms within the same building so that failure of one router does not interrupt service. The maintenance was intended to upgrade one router at a time over several days, with traffic diversions at each step and verification between steps that the network has returned to a fully-connected state. However, a procedural error in the manually orchestrated upgrade process caused the complete list of transceiver replacements across all routers to be issued to the technician without instructions to sequence the work one router at a time. The maintenance workflow also did not include the expected human and software verification steps for detecting unintended disruption. As a result, the technician sequentially unplugged all fiber paths across the affected devices within 13 minutes. The speed and nature of the error prevented warnings of incorrect action from reaching the engineer before connectivity was lost. Additionally, a standing procedure to halt if light is detected on any fiber-optic cable after unplug was not followed. This resulted in compute capacity in the impacted zone being isolated from the network. Customers were unable to reach their virtual machines, and those virtual machines could not establish connections outside their zone. ## Remediation and Prevention The issue was detected immediately by automated network loss monitoring systems as well as proactive probes, which rapidly engaged the network engineering and incident response teams. To mitigate the immediate customer impact, engineering teams actively moved traffic away from the impacted infrastructure. Concurrently, hardware operations technicians on site identified the disconnected optical links and physically re-inserted the original optical transceivers. Once the physical links were fully restored, traffic flow rates normalized and the traffic was redirected back to return the capacity to service. Google is committed to preventing a repeat of this issue in the future and is completing the following actions: * Reinforce training in us-central1 region and globally around safe maintenance techniques, including the mandatory requirement to verify whether light is on every unplugged fiber. * Finish the migration of network upgrade workflows to a fully automatically sequenced orchestration system. Most common regional network workflows were completed in 2025, and zonal workflows are in progress. * Complete the deployment of work stop alerting for actions resulting in the unintended disconnection of live fiber cables in Google data centers. * Complete the deployment of the automated system that will move regional traffic away from faulty zones, reducing the time from approximately 19 minutes in this instance to around 5 minutes. ## Detailed Description of Impact On Tuesday, 1 September, from 07:41 to 11:52 US/Pacific, a portion of the us-central1-b and us-central1-f zones experienced severe network degradation and resource isolation. 1. Multiple products affected: The network disruption to/from a portion of us-central1-b and us-central1-f zones impacted all zonal GCP Products for some customers in those zones. 2. Regional impact: Regional products using capacity in the affected data center were affected until traffic diversions were fully in place at 08:00 US/Pacific. Google Kubernetes Engine and Cloud Run / Google App Engine had longer impacts, discussed below. 3. Error rate: Traffic flow drop rates for resources hosted in the affected area reached 100% during the peak of the incident, resulting in unreachable virtual machines and elevated packet loss. **Affected Services and Features** * Google Compute Engine: Inability for users in the affected portion of us-central1-b and us-central1-f zones to access virtual machines externally, and inability for VMs to reach remote resources. * Cloud SQL, AlloyDB for PostgreSQL, Google Cloud Bigtable, Cloud Filestore: Data access and connectivity severed for instances localized strictly to the impacted infrastructure. * Cloud Spanner, Cloud Firestore: Elevated Remote Procedure Call (RPC) error rates, write timeouts, and latency spikes for the nam5 multi-region instances due to severed connectivity to components running in the impacted zone. * Virtual Private Cloud (VPC), Cloud NAT, Apigee, Google BigQuery, Google Cloud Dataflow, Looker, Google SecOps SOAR, Hybrid Connectivity, Cloud Interconnect: Elevated network packet loss, connectivity drops, and API timeouts in the impacted zone. * Google Kubernetes Engine (GKE): Between 07:40 and 09:15 US/Pacific on 2026-09-01, customers experienced errors and timeouts on requests to their GKE cluster control planes (Kubernetes API servers) in us-central1. This could have caused new or updated workloads to fail scheduling and Kubernetes API operations to fail. * Cloud Run / Google App Engine: Temporary latency spikes and pending queue aborts as backend workloads automatically evacuated and shifted to healthy capacity. A subset of workloads in the specifically impacted area experienced degradation until 11:52 US/Pacific. **Customer Impact** Customers with resources hosted in the specific affected clusters within us-central1-b and us-central1-f experienced a complete loss of network connectivity starting at 07:41 US/Pacific. During this time, virtual machines and associated services became unreachable from the internet and from other Google Cloud regions, and those internal resources could not initiate outbound connections. The issue was detected almost immediately and engineers took traffic diversion actions at 07:45 and 08:00 US/Pacific to reduce impact to regional products. By 08:50 US/Pacific, the majority of physical connections were restored and traffic began recovering, and the traffic diversion actions were removed at 09:19 US/Pacific. Full recovery across nearly all affected services and long-running operations was confirmed by 11:52 US/Pacific. Because the network isolation was strictly limited to specific clusters within us-central1-b and us-central1-f, multi-zonal deployments correctly utilizing redundancy across other zones in us-central1 were largely able to bypass the physical hardware failure and continue serving traffic. Customers with projects in both us-central1-b and us-central1-f would not have seen multi-zonal impact - at most one of their zones would have capacity in the affected data center. --- [2026-09-03T17:47:02+00:00] (AVAILABLE) ## Preliminary Incident Report We sincerely apologize for the disruption this incident caused to your business. We know how much you rely on Google Cloud, and we regret the impact on your environment. We are working to address the root cause and prevent this from occurring in the future. Please note, this information is based on our best knowledge at the time of posting and is subject to change as our investigation continues. A final Incident Report with preventative actions will be posted once our investigation is complete. If you have experienced impact outside of what is listed below, please reach out to Google Cloud Support using https://cloud.google.com/support ## Date/Time of the Issue (All time US/Pacific) **Incident Start**: 1 September 2026 07:41 **Incident End**: 1 September 2026 11:52 **Duration**: 4 hours, 11 minutes ## Summary On Tuesday, 1 September 2026, some customers in us-central1-b experienced network service degradation and instance isolation for a duration of 4 hours and 11 minutes. To our customers whose businesses were impacted during this disruption, we sincerely apologize. This is not the level of quality and reliability we strive to offer you, and we are taking immediate steps to improve the platform’s performance and availability. ## Preliminary Root Cause The immediate technical trigger for this event was the inadvertent physical disconnection of network fiber-optic cables during a routine hardware maintenance procedure. An engineer was performing a scheduled capacity upgrade on datacenter routers that support a fraction of capacity in the us-central1-b zone. The network architecture for each datacenter is designed with redundancy across multiple routing devices. The system is designed to be resilient to all single device or fiber-path failures, and most double- or triple-failures do not affect customer traffic. To ensure this, the devices and fiber paths are physically separated in each datacenter, with diverse power sources. A procedural error meant that the physical maintenance action sequentially unplugged 100% of fiber paths across all devices within 13 minutes. The nature of the error, combined with the speed of the action, prevented warnings of incorrect action reaching the engineer before complete disconnection. This resulted in compute capacity in the impacted zone being isolated from the network. Customers were unable to reach their virtual machines, and those virtual machines could not establish connections outside their zone. ## Remediation The issue was detected immediately by automated network loss monitoring systems as well as proactive probes, which rapidly engaged the network engineering and incident response teams. To mitigate the immediate customer impact, engineering teams actively moved traffic away from the impacted infrastructure, automatically shifting compatible workload traffic to healthy capacity elsewhere in the region. Concurrently, hardware operations technicians on site identified the disconnected optical links and physically reseated the fibers. Once the physical links were fully restored, traffic flow rates normalized and the traffic was redirected back to return the capacity to service. ## Description of Impact On Tuesday, 1 September, from 07:41 to 11:52 US/Pacific, a portion of the us-central1-b zone experienced severe network degradation and resource isolation. * **Multiple products affected:** The network disruption to/from a portion of us-central1-b impacted multiple GCP Products for some customers in that zone. * **Error rate:** Traffic flow drop rates for resources hosted in the affected area reached 100% during the peak of the incident, resulting in unreachable virtual machines and elevated packet loss. **Affected Services and Features** * **Google Compute Engine:** Inability to access virtual machines externally, and inability for VMs to reach remote resources. * **Google Kubernetes Engine:** Unreachable regional/zonal clusters and nodes within the affected zone, prompting delayed cluster recovery times. * **Cloud Run / Google App Engine:** Temporary latency spikes and pending queue aborts as backend workloads automatically evacuated and shifted to healthy capacity. A subset of workloads in the specifically impacted area experienced degradation until 11:52 US/Pacific. * **Cloud SQL, AlloyDB for PostgreSQL, Cloud Spanner, Google Cloud Bigtable, Cloud Filestore:** Data access and connectivity severed for instances localized strictly to the impacted infrastructure. * **Virtual Private Cloud (VPC), Cloud NAT, Apigee, Google BigQuery, Google Cloud Dataflow, Looker, Google SecOps SOAR, Hybrid Connectivity, Cloud Interconnect:** Elevated network packet loss, connectivity drops, and API timeouts in the impacted zone. --- [2026-09-01T19:12:28+00:00] (SERVICE_DISRUPTION) **Summary** Multiple products in us-central1-b experienced network service degradation. **Description** The issue was affecting a portion of the us-central1-b zone. The remaining zones in the region were unaffected. All the impacted products have recovered. From preliminary analysis, routine network fabric path maintenance triggered unexpected issues in one cluster in us-central1-b. We have recovered the network capacity that was impacted and restored all zonal and regional services. Maintenance in the region has been halted while proactive audits are carried out. We thank you for your patience while we worked on resolving the issue. **Customer Symptoms** Customers experienced elevated packet loss and errors. **Workaround** The issue has been mitigated. --- [2026-09-01T18:36:56+00:00] (SERVICE_DISRUPTION) **Summary** Multiple products in us-central1-b are experiencing network service degradation. **Description** The issue is affecting a portion of the us-central1-b zone. The remaining zones in the region are unaffected. Most of the products have recovered. The impacted products Cloud Run and App Engine are also seeing recovery and the errors have lowered pre-incident levels. Engineering continues to monitor and validate. Routine network fabric path maintenance triggered unexpected issues in two clusters in us-central1-b. We have recovered the network capacity that was impacted and restored all zonal and regional services. Maintenance in the region has been halted while proactive audits are carried out. We will provide more information by Tuesday, 2026-09-01 12:30 US/Pacific with current details. **Customer Symptoms** Customers are experiencing elevated packet loss and errors. * Cloud Run * App Engine Following products have recovered * BigQuery * Cloud Dataflow * Cloud Bigtable * Compute Engine * Cloud Hybrid Connectivity * Cloud Filestore * Virtual Private Cloud * Cloud Spanner * Google Kubernetes Engine * Cloud SQL * AlloyDBCloud VPN * Apigee * Cloud Interconnect * Cloud NAT * Looker (Google Cloud core) * Google SecOps SOAR * Cloud Firestore **Workaround** * Customers with service layer retries may see successful completions as only a portion of the zone is affected. --- [2026-09-01T18:01:09+00:00] (SERVICE_DISRUPTION) **Summary** Multiple products in us-central1-b are experiencing network service degradation. **Description** The issue is affecting a portion of the us-central1-b zone. The remaining zones in the region are unaffected. Most of the products have recovered and the engineering team is still validating a few remaining product impacts. Routine network maintenance triggered issues in us-central1-b. We have recovered the network capacity that was impacted and restored all zonal and regional services. Maintenance in the region has been halted while proactive audits are carried out. We will provide more information by Tuesday, 2026-09-01 12:30 US/Pacific with current details. **Customer Symptoms** Customers are experiencing elevated packet loss and errors. * Cloud Run * App Engine Following products have recovered * BigQuery * Cloud Dataflow * Cloud Bigtable * Compute Engine * Cloud Hybrid Connectivity * Cloud Filestore * Virtual Private Cloud * Cloud Spanner * Google Kubernetes Engine * Cloud SQL * AlloyDBCloud VPN * Apigee * Cloud Interconnect * Cloud NAT * Looker (Google Cloud core) * Google SecOps SOAR * Cloud Firestore **Workaround** * Customers with service layer retries may see successful completions as only a portion of the zone is affected. --- [2026-09-01T17:09:04+00:00] (SERVICE_DISRUPTION) **Summary** Multiple products in us-central1-b are experiencing network service degradation. **Description** The issue is affecting a portion of the us-central1-b zone. The remaining zones in the region are unaffected. Most of the products have recovered and the engineering team is still validating a few remaining product impacts. We will provide more information by Tuesday, 2026-09-01 11:00 US/Pacific with current details. **Customer Symptoms** Customers are experiencing elevated packet loss and errors. * Cloud Run * App Engine Following products have recovered * BigQuery * Cloud Dataflow * Cloud Bigtable * Compute Engine * Cloud Hybrid Connectivity * Cloud Filestore * Virtual Private Cloud * Cloud Spanner * Google Kubernetes Engine * Cloud SQL * AlloyDBCloud VPN * Apigee * Cloud Interconnect * Cloud NAT * Looker (Google Cloud core) * Google SecOps SOAR * Cloud Firestore **Workaround** * Customers with service layer retries may see successful completions as only a portion of the zone is affected. * Customers that are severely affected and have services available in alternate zones can failover to alternate zones. --- [2026-09-01T16:19:12+00:00] (SERVICE_DISRUPTION) **Summary** Multiple products in us-central1-b are experiencing network service degradation. **Description** The issue is affecting a portion of the us-central1-b zone. The remaining zones in the region are unaffected. Following network-level mitigation efforts, the underlying network infrastructure has fully recovered. Product engineering teams across Cloud are currently validating the recovery status of individual services. We will provide more information by Tuesday, 2026-09-01 10:00 US/Pacific with current details. **Customer Symptoms** Customers are experiencing elevated packet loss and errors. * BigQuery * Cloud Dataflow * Cloud SQL * App Engine * Cloud Run * AlloyDB * Cloud Bigtable * Cloud Spanner * Compute Engine * Cloud VPN * Cloud Interconnect * Cloud NAT * Cloud Filestore * Cloud Hybrid Connectivity * Virtual Private Cloud * Google Kubernetes Engine * Looker (Google Cloud core) * Apigee * Google SecOps SOAR **Workaround** * Customers with service layer retries may see successful completions as only a portion of the zone is affected. * Customers that are severely affected and have services available in alternate zones can failover to alternate zones. --- [2026-09-01T16:03:12+00:00] (SERVICE_DISRUPTION) **Summary** Multiple products in us-central1-b are experiencing network service degradation.  **Description** We are experiencing a networking issue starting Tuesday, 2026-09-01 07:41 US/Pacific. The issue is affecting a portion of the us-central1-b zone. The remaining zones in the region are unaffected. Our network engineering team has put in mitigations and we are seeing services starting to recover. We will provide more information by Tuesday, 2026-09-01 09:30 US/Pacific with current details. We apologize to all who are affected by the disruption. **Customer Symptoms** Customers are experiencing elevated packet loss and errors. * BigQuery * Cloud Dataflow * Cloud SQL * App Engine * Cloud Run * AlloyDB * Cloud Bigtable * Cloud Spanner * Compute Engine * Cloud VPN * Cloud Interconnect * Cloud NAT * Cloud Filestore * Cloud Hybrid Connectivity * Virtual Private Cloud * Google Kubernetes Engine * Looker (Google Cloud core) **Workaround** * Customers with service layer retries may see successful completions as only a portion of the zone is affected. * Customers that are severely affected and have services available in alternate zones can failover to alternate zones.

# Incident Report ## Summary On Thursday, 20 August 2026, from 08:00 to 10:22 US/Pacific (15:00 to 17:22 UTC), multiple Google Cloud services in the us-west1 region experienced elevated latency, provisioning failures, increased error rates, and widespread service degradations for a total duration of 2 hours and 22 minutes. The incident impacted a wide range of core services — including Persistent Disk, Google Kubernetes Engine, Google Compute Engine, Cloud Run, Google Cloud Bigtable, Cloud Storage, and Identity and Access Management — across both control plane operations and data plane requests. We sincerely apologize for the disruption this incident caused to your business operations and critical workloads. We recognize the vital role Google Cloud plays in supporting your organization, and we deeply regret the impact on your business operations and critical workloads. Engineering and infrastructure teams are actively implementing measures to address the root causes and strengthen network resiliency to prevent recurrences in the future. Specifically, teams are monitoring recovery progress, refining safety checks for planned optical maintenance, and optimizing regional traffic routing mechanisms to safeguard against unexpected capacity constraints. ## Root Cause The disruption originated during scheduled fiber optic maintenance, which unexpectedly compromised network capacity between data centers within the us-west1 region. Automated rerouting mechanisms failed to properly redistribute traffic to alternate capacity, resulting in network congestion as volumes exceeded available bandwidth in the affected area. This underlying network degradation subsequently impacted higher-level service components through severe packet loss, request throttling, and increased latency across inter-campus dependencies. Core infrastructure services, including Spanner Paxos consensus and the Unified Metadata Server (UMS), experienced significant latency spikes, which cascaded into timeouts and elevated error rates for downstream dependent products such as Cloud Storage, Cloud IAM, Persistent Disk, and Google Kubernetes Engine. Consequently, both control plane operations and data plane requests failed to execute successfully across multiple Google Cloud services in us-west1 throughout the duration of the incident. ## Remediation and Prevention Internal monitoring systems initially detected widespread service anomalies and alerted Google engineers, who promptly confirmed that multiple core services operating across the us-west1 region were severely impacted. In response to the immediate operational risks, engineering teams promptly executed emergency traffic draining protocols to reroute active service workloads away from the compromised inter-campus network infrastructure and minimize further customer disruption. Once teams restored inter-campus fiber network capacity, engineers systematically reintroduced production traffic back to us-west1 through controlled validation stages, ultimately confirming full service normalization across all impacted platforms. Longer term engineering remediations and architectural enhancements are actively being finalized and assigned to owning teams. Key focus areas include reforming scheduled maintenance protocols, establishing stricter safety checks and circuit redundancy requirements prior to routine maintenance, and refining automated regional traffic failover mechanisms to automatically handle sudden capacity degradation without incurring severe network congestion. ## Detailed Description of Impact On Thursday, August 20, between 08:00 and 10:22 US/Pacific, Google Cloud customers in the us-west1 region encountered elevated latency, provisioning failures, and increased error rates. * **Impact / Error Rates:** The reduced capacity caused request throttling, latency spikes, and increased retry volume. * **Scope Exclusion:** Services and workloads operating in regions other than us-west1 remained fully operational and unaffected. **Affected Services and Features** The following services experienced elevated latencies and/or increased error rates, across their respective data planes and control planes: * AlloyDB * Apache Kafka * Apigee Edge Public Cloud * Apigee X * Artifact Registry * BigQuery & BigQuery Data Transfer Service * Cloud Build * Cloud Data Fusion * Cloud Dataflow * Cloud Filestore * Cloud Key Management Service (KMS) * Cloud Monitoring * Cloud Run * Cloud SQL * Contact Center AI Platform * Dataproc Metastore * Google App Engine * Google Cloud Bigtable * Google Cloud Pub/Sub * Google Cloud Storage (GCS) * Google Compute Engine (GCE) * Google Kubernetes Engine (GKE) * Identity and Access Management (IAM) * Managed Airflow (Cloud Composer) * Managed Service for Apache Spark (Dataproc) * Persistent Disk The regional incident in us-west1 followed a structured three-phase recovery dictated by platform dependency layers: While core platform connectivity and live request serving were restored by 10:22 US/Pacific, certain services took additional time to fully recover due to asynchronous backlog processing and localized control-plane state reconciliation for a very small set of customers. For event-driven and pipeline services, inbound error rates dropped to 0 immediately, but some operations experienced elevated latency while workers processed through backlogs accumulated during the outage, clearing later for Cloud Pub/Sub, Cloud Build & Deploy, Cloud Dataflow, and Cloud Storage lifecycle deletions. Concurrently, while primary read/write traffic was healthy across the region, specific long-running lifecycle workflows required extra time to clear locks and reconcile distributed state machines. Compute Engine VM provisioning in zone us-west1-c and Cloud Filestore control plane instance allocation locks and resource validation checks took longer to normalize across regional storage backends. --- [2026-08-25T06:20:02+00:00] (AVAILABLE) # Preliminary Incident Report We sincerely apologize for the disruption this incident caused to your business operations. Recognizing your reliance on Google Cloud, we express our sincere regrets for any operational impact experienced. Our engineering teams are actively addressing the underlying root cause to prevent future recurrences. Please note that the information provided herein reflects our current understanding as of the time of publication and remains subject to revision as the investigation progresses. A comprehensive Incident Report detailing preventive measures will be issued upon conclusion of our inquiry. If you have experienced impact outside of what is listed below, please reach out to Google Cloud Support using https://cloud.google.com/support. ## Date/Time of the Issue (All time US/Pacific) * Incident Start: 20 August 2026 08:00 * Incident End: 20 August 2026 10:22 * Duration: 2 hours, 22 minutes ## Summary On Thursday, 20 August 2026, multiple Google Cloud services encountered elevated latency, provisioning failures, increased error rates, and service degradations lasting for a duration of 2 hours and 22 minutes. ## Preliminary Root Cause The disruption originated during scheduled fiber optic maintenance, which unexpectedly compromised network capacity between data centers within the us-west1 region. Automated rerouting mechanisms failed to properly redistribute traffic to alternate capacity, resulting in network congestion as volumes exceeded available bandwidth in the affected area. This underlying network degradation subsequently impacted higher-level service components through request throttling, increased latency, and cascading retries. Consequently, both control plane operations and data plane requests failed to execute successfully across several dependent Google Cloud services, producing the observed latency and elevated error rates. ## Remediation Internal monitoring alerted Google engineers to the incident, confirming that multiple services across us-west1 were affected. To mitigate the immediate operational impact, engineers initiated traffic draining protocols, re-routing service workloads away from the degraded network infrastructure. Following the restoration of inter-campus network capacity and the resolution of the core issue, engineers systematically restored traffic to the us-west1 region and confirmed service normalization. Long-term engineering solutions are currently being finalized and assigned to address the root cause and strengthen system resilience regarding fiber maintenance procedures. ## Description of Impact On Thursday, August 20, between 08:00 and 10:22 US/Pacific, Google Cloud customers in the us-west1 region encountered elevated latency, provisioning failures, and increased error rates. * Proportionate Impact / Error Rates: The precise scope of impact—including the proportion of affected projects and applications—and detailed error metrics will be published in the comprehensive Root Cause Analysis, as the reduced capacity caused request throttling, latency spikes, and increased retry volume. * Scope Exclusion: Services and workloads operating in regions other than us-west1 remained fully operational and unaffected. **Affected Services and Features** The following services experienced elevated latencies and/or increased error rates, across their respective data planes and control planes: * AlloyDB * Apache Kafka * Apigee Edge Public Cloud * Apigee X * Artifact Registry * BigQuery & BigQuery Data Transfer Service * Cloud Build * Cloud Data Fusion * Cloud Dataflow * Cloud Filestore * Cloud Key Management Service (KMS) * Cloud Monitoring * Cloud Run * Cloud SQL * Contact Center AI Platform * Dataproc Metastore * Google App Engine * Google Cloud Bigtable * Google Cloud Pub/Sub * Google Cloud Storage (GCS) * Google Compute Engine (GCE) * Google Kubernetes Engine (GKE) * Identity and Access Management (IAM) * Managed Airflow (Cloud Composer) *Managed Service for Apache Spark (Dataproc) Persistent Disk --- [2026-08-20T19:37:40+00:00] (AVAILABLE) **Summary** The issue causing timeouts, degradations, errors, and latencies across multiple us-west1 products has been mitigated. **Description** We have mitigated the issue impacting multiple products in our us-west1 region as of Thursday, 2026-08-20 10:22 PDT. Our engineering teams have restored capacity on a planned optical maintenance that caused unexpected congestion in Dalles, Oregon metro /us-west1 region. Our systems stabilized and services have recovered once capacity was restored. Our teams are continuing to monitor for any residual impact. We will publish an analysis of this incident once we have completed our internal investigation. We thank you for your patience while we worked on resolving the issue. **Diagnosis / Customer Symptoms** Customers in us-west1 may have experienced timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** This issue is now mitigated. --- [2026-08-20T19:21:07+00:00] (SERVICE_OUTAGE) **Summary** The issue causing timeouts, degradations, errors, and latencies across multiple us-west1 products has been mitigated and we are working to recover all products. **Description** Mitigation actions have been completed by our engineering teams and we are seeing recovery from multiple products. We are continuing to work to recover the remaining products. We will provide an update by Thursday, 2026-08-20 13:30 PDT with details. **Diagnosis / Customer Symptoms** Customers in us-west1 may experience timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** No workarounds needed at this time. --- [2026-08-20T18:53:26+00:00] (SERVICE_OUTAGE) **Summary** The issue causing timeouts, degradations, errors, and latencies across multiple us-west1 products has been mitigated and we are working to recover all products. **Description** Mitigation actions have been completed by our engineering teams and we are seeing recovery from multiple products. We are continuing to work to recover the remaining products. We will provide an update by Thursday, 2026-08-20 12:30 PDT with details. **Diagnosis / Customer Symptoms** Customers in us-west1 may experience timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** No workarounds needed at this time. --- [2026-08-20T18:03:07+00:00] (SERVICE_OUTAGE) **Summary** The issue causing timeouts, degradations, errors, and latencies across multiple us-west1 products has been mitigated and we are working to recover all products. **Description** Mitigation actions have been completed by our engineering teams and we are seeing recovery from multiple products. We are continuing to work to recover the remaining products. We will provide an update by Thursday, 2026-08-20 11:45 PDT with details. **Diagnosis / Customer Symptoms** Customers in us-west1 may experience timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** No workarounds needed at this time. --- [2026-08-20T17:32:15+00:00] (SERVICE_OUTAGE) **Summary** We are investigating an issue where customers may experience timeouts, service degradations, errors, and elevated latencies across multiple products in the us-west1 region. **Description** Mitigation actions are implemented by our engineering teams, recovery trends have been observed across infrastructure layers. Active efforts remain underway to bring impacted cloud services back to full operation. We will provide an update by Thursday, 2026-08-20 11:00 PDT with details. **Diagnosis / Customer Symptoms** Customers in us-west1 may experience timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** We recommend customers to failover to other regions where feasible. --- [2026-08-20T17:13:59+00:00] (SERVICE_OUTAGE) **Summary** We are investigating an issue where customers may experience timeouts, service degradations, errors, and elevated latencies across multiple products in the us-west1 region. **Description** Mitigation actions are implemented by our engineering teams, recovery trends have been observed across infrastructure layers. Active efforts remain underway to bring impacted cloud services back to full operation. We will provide an update by Thursday, 2026-08-20 10:45 PDT with details. **Diagnosis / Customer Symptoms** Customers in us-west1 may experience timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** We recommend customers to failover to other regions where feasible. --- [2026-08-20T16:44:37+00:00] (SERVICE_OUTAGE) **Summary** We are investigating an issue where customers may experience timeouts, service degradations, errors, and elevated latencies across multiple products in the us-west1 region. **Description** We are experiencing an issue with multiple products, beginning on Thursday, 2026-08-20 08:40 PDT. Our engineering team continues to investigate the issue. We will provide an update by Thursday, 2026-08-20 10:30 PDT with details. We apologize to all who are affected by the disruption. **Diagnosis / Customer Symptoms** Customers in us-west1 may experience timeouts, service degradations, errors, and elevated latencies across multiple products. **Workaround** None at this time.