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leden 2025

8

This is our Preliminary PIR to share what we know so far. After our internal retrospective is completed (generally within 14 days) we will publish a Final PIR with additional details. 

What happened? 

Between 22:31 UTC on 08 Jan 2025 and 04:30 UTC on 11 Jan 2025, a networking configuration change in a single Availability Zone (Physical Zone Az01) in East US 2 resulted in customers experiencing connectivity issues, prolonged timeouts, connection drops and resource allocation failures across multiple Azure services. Customers leveraging Private Link with Network Security Groups to communicate with Azure services may have also been impacted.  

The 'logical' Availability Zones used by each customer subscription may correspond to different physical Availability Zones - customers can use the Locations API to understand this mapping, to confirm which resources run in this physical AZ - .  

Services that were configured to be zonally redundant and leveraging VNET injection may have experienced multi-zone impact. Impacted services included API Management, Azure App Service, Azure Container Apps, Azure Container Instances, Azure Container Service, Azure Data Factory, Azure Database for PostgreSQL flexible servers, Azure Databricks, Azure Databricks, Azure Function Apps, Azure Functions, Azure Logic Apps, Azure NetApp Files, Azure RedHat Openshift, Azure Stream Analytics, Azure Synapse, Azure Synapse Analytics, Container Instances, DevOps, PowerBI, SQL Managed Instance, SQL Managed Instances, Virtual Machine Scale Sets, Virtual machines, and Virtual Machine Scale Sets. 

What went wrong and why? 

The Azure PubSub service provides real-time, bi-directional communication between servers and clients. This is essential for deployments, resource allocation, and traffic management within an Azure Virtual Network environment. It handles all networking configurations, including customer resource configurations and virtual machine (VM) routing information mapping customer addresses to physical addresses. The PubSub Service also stores these network configurations, allowing agents to retrieve them as needed, such as after a restart. Networking agents on host machines access resource configurations and routing information from the control plane through the Azure PubSub service. 

Around 22:31 UTC on 8 Jan 2025, a manual recycling of the internal PubSub replicas on certain metadata partitions was intended to enable a feature flag. Typically speaking, these ‘partition recycles’ are executed in series to ensure that data quorum between the partition is maintained. The command restarted the replicas in parallel, which caused us to lose the indexing data on these partitions.  

Losing this indexing data resulted in ~60% of network configurations to be unable to be delivered to agents from the control plane which impacted all service management operations for resources with index data on the affected partitions. In addition, networking agents would have also failed to receive updates on VM routing information for new and existing VMs that underwent any automated recovery. This would have manifested in a loss of connectivity. This affected VMs that customers use, in addition to the VMs that underpin our PaaS service offerings. This also affected zonally resilient PaaS services that have dependency on virtual network injection.  

How did we respond? 

The issue was immediately detected by the monitoring on the PubSub service at 22:44 UTC on 08 Jan 2025, with all the impacted services raising alerts shortly thereafter. The PubSub team identified the trigger as the three partitions with indexing data loss due to the recycling.  

Several mitigation workstreams were initiated in parallel.  

At 03:45 UTC on 9 Jan 2025, we completed our first remediation step to the Azure control plane service that was running on the impacted host machines to point to PubSub endpoints located in other nonimpacted availability zones. This restored the host agent’s ability to look up the correct routing information resulting in mitigating VM to VM connectivity issues. 

At 05:00 UTC on 9 Jan 2025, another remediation to route all new allocations requests to other availability zones in East US 2 was completed. Services that were using platform features that had a fixed dependency on the impacted zone may have continued to see failures.  

At 18:17 UTC on 09 Jan 2025, another remediation to redirect Private Link mapping (look ups) to avoid the dependency on the impacted zone was completed resulting in all Private Link data path being restored. 

Some of our impacted services initiated their Disaster Recovery playbooks to help mitigate impact for their customers.  

The main workstream for full mitigation was to rebuild the 3 impacted partitions in the PubSub service.  

By 19:18 UTC on 10 Jan 2025, all three impacted partitions were fully recovered. Following this, we started working with impacted services to validate the health of their resources. At 00:30 UTC on the 11 Jan 2025, we initiated a phased approach to gradually enable the impacted zone for new allocations. By 00:44 UTC on 11 Jan 2025, all services confirmed mitigation. We reintroduced the impacted Availability Zone into rotation fully at 04:30 UTC, at which point we declared full mitigation. The impact window for Azure Services varied between service. 

Below is a preliminary assessment of the timeline of events: 

  • 22:31 UTC on 08 Jan 2025 – Customer impact begins.  
  • 22:42 UTC on 08 Jan 2025 – The impact is understood and a workstream to route traffic away from the impacted zone is initiated. 
  • 22:44 UTC on 08 Jan 2025 – The issue is identified as an incorrect networking configuration. 
  • 22:50 UTC on 08 Jan 2025 – A workstream to recover the indexing data and rehydrate the impacted partitions is initiated. 
  • 23:43 UTC on 08 Jan 2025 – Targeted customer communications from impacted services started going out via Azure Service Health. 
  • 02:37 UTC on 09 Jan 2025 – Azure Status page updated with the details of a wider networking impact to the region. 
  • 03:05 UTC on 09 Jan 2025 - A workstream to route all new allocation requests to other availability zones in East US 2 is initiated. 
  • 03:45 UTC on 09 Jan 2025 – The workstream to route traffic away from Az01 is completed. 
  • 05:00 UTC on 09 Jan 2025 – The workstream to route all new allocation requests to other availability zones in East US 2 was completed. 
  • 11:58 UTC on 09 Jan 2025 – The workstream to mitigate impacted services with Private link and NSG dependency is initiated. 
  • 18:17 UTC on 09 Jan 2025 – The workstream to redirect Private Link mapping (look ups) to avoid the dependency on the impacted zone is completed. 
  • 19:18 UTC on 10 Jan 2025 – All three of the impacted partitions are fully recovered and validated. 
  • 00:30 UTC on 11 Jan 2025 – We initiated a phased approach to gradually enable the impacted zone for new allocations. 
  • 00:44 UTC on 11 Jan 2025 - All services confirmed mitigation. 
  • 04:30 UTC on 11 Jan 2025 – Az01 was confirmed to be back to full operational health.  

How are we making incidents like this less likely or less impactful?  

  • We are conducting an in-depth analysis of all learnings from the issue, and we will provide an update in the Final PIR.  
  • Effective immediately, all potentially high impacting changes are undergoing additional layers of validation and checks.  
  • We are taking steps to minimize manual touch of production systems and follow our safe deployment practices for required configuration changes in production.   
  • We are Improving our backup and restore mechanisms of stateful services and conducting regular data recovery drills to reduce the recovery time during data loss.    
  • We are Improving resiliency of the platform to avoid regional resources being impacted by zonal service unavailability. 

How can we make our incident communications more useful? 

You can rate this PIR and provide any feedback using our quick 3-question survey:  

prosinec 2024

26

What happened? 

Between 18:40 UTC on 26 December and 19:30 UTC on 27 December 2024, multiple Azure services were impacted by a power event that occurred in one datacenter, within one Availability Zone (physical zone AZ03), in the South Central US region. Within the impacted datacenter, our automated power systems managed the event as expected, without interruption for two of the three data halls. However, one data hall did not successfully transition to an alternate power supply. This failure led to a loss of compute, network, and storage infrastructure in this data hall.  

Customer workloads configured for multi-zone resiliency would have seen no impact, or only brief impact, as automated mitigations occurred. Only customer workloads without multi-zone resiliency, and with dependencies on the impacted infrastructure, became degraded or unavailable. Impacted downstream services included: 

• Azure Alerts Management – between 18:40 UTC 26 December 2024 and 05:00 UTC on 27 December 2024, impacted customers may have experienced high latency in alerts notifications and persistence.

• Azure App Service – between 18:40 UTC on 26 December and 12:00 UTC on 27 December, impacted customers may have received intermittent HTTP 500-level response codes, experience timeouts or high latency when accessing App Service (Web, Mobile, and API Apps), App Service (Linux), or Function deployments hosted in the South Central US region.

• Azure Application Gateway – between 18:40 UTC on 26 December and 06:58 UTC on 27 December, impacted customers may have experienced data plane disruptions when trying to access your backend applications using Application Gateway hosted in the South Central US region.

• Azure Backup – between 20:40 UTC on 26 December and 02:21 UTC on 27 December, impacted customers may have experienced failures in backup operations for Azure File shares in the South Central US region.

• Azure Cache for Redis – between 18:45 and 21:35 UTC on 26 December, impacted customers may have lost cache availability and/or been unable to connect to cache resources hosted in the South Central US region.

• Azure Cosmos DB – between 18:47 UTC on 26 December and 03:59 UTC on 28 December, impacted customers may have experienced a degradation in service availability and/or request latency. Some requests may have resulted in server errors or timeouts.

• Azure Database for PostgreSQL – between 18:48 UTC on 26 December and 13:12 UTC on 27 December, impacted customers may have experienced connectivity failures and timeouts when executing operations, as well as unavailability of resources hosted in the South Central US region.

• Azure Database Migration Service – between 19:01 UTC on 26 December and 12:17 UTC on 27 December, impacted customers may have experienced timeout errors when attempting to create a new migration service, or when using existing migration service in the South Central US region.

• Azure Event Hubs | Azure Service Bus – Customers with Standard SKU, Premium SKU namespaces or AZ-enabled dedicated Event Hubs clusters experienced an availability drop for approximately five minutes, at the time when the incident started – this issue was mitigated automatically once namespace resources were reallocated to other availability zones. However, a subset of customers using Event Hubs Dedicated non-AZ clusters experienced an availability issue for an extended period of time when trying to access their Event Hubs namespaces in the region. The affected Event Hubs dedicated clusters recovered once the underlying failing VMs in their clusters were brought back online, the last of which were restored by 05:52 UTC on 27 December.

• Azure Firewall – between 18:44 UTC on 26 December and 11:30 UTC on 27 December, impacted customers with an Azure Firewall deployed with multi-zone resilience may have seen partial throughput degradation and no availability loss. Customers with an Azure Firewall not utilizing multi-zone resiliency may have had resources dependent on the impacted Availability Zone (physical zone AZ03) which could have resulted in performance degradation or availability impact. Customers attempting control plane operations (for example, making changes to Firewall policies/rules) may have experienced failures during this incident.

• Azure Logic Apps – between 18:47 UTC on 26 December and 03:10 UTC on 27 December, impacted customers may have encountered delays in run executions and failing data or control plane calls.

• Azure SQL Database – between 20:12 UTC on 26 December and 18:22 UTC on 27 December, impacted customers may have experienced issues accessing services. New connections to databases in the South Central US region may have resulted in an error or timeout. Existing connections remained available to accept new requests, however if those connections were terminated then re-established, they may have failed.

• Azure Storage – between 18:45 UTC on 26 December and 08:50 UTC on 27 December, impacted customers may have experienced timeouts and failures when accessing storage resources hosted in the South Central US region. This affected both Standard and Premium tiers of Blobs, Files and Managed Disks.

• Azure Synapse Analytics – between 18:53 UTC on 26 December and 13:52 UTC on 27 December, impacted customers may have experienced spark job execution failures, and/or errors when attempting to create clusters, in the South Central US, East US 2, and/or Brazil South regions.

• Azure Virtual Machines – between 18:41 UTC on 26 December and 22:26 UTC on 27 December, impacted customers may have experienced connection failures when trying to access some Virtual Machines hosted in the South Central US region. These Virtual Machines may have also restarted unexpectedly.

• Azure Virtual Machine Scale Sets – between 19:04 UTC on 26 December and 11:18 UTC on 27 December, impacted customers may have experienced error notifications when performing service management operations - such as create, delete, update, scaling, start, stop - for resources hosted in the South Central US region.

• This incident also impacted a subset of Microsoft 365 services – further details are provided in the Microsoft 365 Admin Center, under incident ID MO966473. 

 

What went wrong and why? 

This incident was initially triggered by a utility power loss, itself caused by a localized ground fault – in which a high voltage underground line failed. After a phase to ground short developed in the buried feeder cables, the breaker feeding the datacenter tripped – leading to a loss of utility power, at 18:40 UTC.  

By design, the power distribution systems transferred power to diesel backup generators, where UPS batteries carry the load during this transition, which was successful for two of the three affected data halls. During the transition to generator power, the third data hall experienced UPS battery faults, which caused the load to drop during transition. 

In any power-related event, our first priority is to ensure the safety of our staff and infrastructure before any power restoration work can begin. Following our assessment, we were able to safely begin restoration at 20:13 UTC. IT power loads were manually re-energized on backup diesel generator power, by performing a bypass on the failed UPS devices. We began seeing infrastructure services returning by 20:35 UTC, with power fully restored by 20:56 UTC. As power and infrastructure recovered, the next validation steps were to ensure that Azure Networking and Azure Storage services were recovering as expected. By 21:00 UTC, almost all storage and network infrastructure services were confirmed as fully operational. A single storage scale unit remained significantly degraded, due to hardware that required deeper inspection and ultimately, replacement. 

As storage scale units recovered, 85% of the impacted Virtual Machines (VMs) recovered by 21:40 UTC as their Virtual Hard Disks (VHDs) became available. The next 13% of VMs recovered between 06:00 and 06:30 UTC, as the final storage scale unit became available. Despite all the storage issues being resolved, <2% of VMs impacted by this event remained unhealthy. These issues are detailed below and explain why impacted downstream services with dependencies on these VMs experienced long-tail recoveries. The incident was declared as mitigated at 19:30 UTC on 27 December 2024. 

Azure Storage:

For Zone Redundant Storage (ZRS) accounts, there was no availability impact – as data was served from replicas in other Availability Zones during this incident.  

The power loss event impacted six Storage scale units. After power restoration, scale units hosting Standard SSD Managed Disks, Premium SSD Managed Disks, Premium Blobs, and Premium Files, fully recovered automatically in around 30 minutes. For most of the HDD-based Standard Storage LRS/GRS scale units, the storage services took approximately one hour to recover. 

Unfortunately, within one Standard Storage scale unit, multiple network switches were non-functional following the power event, causing a significant portion of the data in that scale unit to be inaccessible because all replicas were unreachable. This caused significant impact to VMs and dependent services that were using Standard HDD managed disks and LRS blob or file storage accounts hosted on this scale unit. Mitigation required replacement networking equipment to be sourced from spares and installed by datacenter technicians. Network engineers then configured and validated these devices, before bringing them online. Additional actions were taken to recover storage nodes under the replaced switches. For the majority of accounts availability was restored by 06:10 UTC on 27th December 2024 (overall availability at 99.5%), with repairs required on a handful of servers to restore 100% availability by 08:50 UTC on 27 December 2024.  

Azure Compute / Virtual Machines: 

For customers using VM/compute workloads that leveraged multi-zone resiliency (such as VMSS flex across availability zones), there was no availability impact.  

For incidents like this, Azure has an automated recovery suite called ‘Defibrillator’ that starts automatically, to recover the VMs and Host machines they are running on, after datacenter power has been restored. It will orchestrate the power on for all affected Host machines, monitor the boot-up and bootstrap sequences, and ensure that the VMs are up and running. When this is running, Azure’s automated steady-state health detection and remediation systems suspend all activities, in order to avoid disrupting the disaster recovery process.  

At approximately 22:00 UTC on 26 December 2024, some compute scale units were found not tracking at the expected level of recovery. For the final 2% of VMs mentioned above, these experienced an extended recovery – we observed three separate events that contributed to this.  

  • The first scenario was due to initialization without a connection to a network device. Due to the network devices not being fully configured before the Host machines were powered on, a race condition triggered during the Host bootstrap process. This issue is specific to a certain hardware configuration within localized compute scale units, and necessitated the temporary disabling of some validation checks during the bootstrap process.
  • The second scenario delaying recovery was some machines failing to boot into the Host OS due to a newly discovered bootloader bug impacting a small subset of host hardware with higher levels of offline memory pages. When the hardware reports repeated corrected memory errors to the Host OS, the Host will offline certain memory ranges to prevent repeated use of that memory range. In a small subset of host hardware where a large range of offline memory was accumulated, this new Host OS bug was discovered – resulting in failing to bootstrap the Host OS. This category was mitigated by clearing and/or ignoring this offline memory list and allowing the Host OS to make forward progress where it could, then rebuild its offline memory list once it started to run the full OS.
  • The third scenario that had prevented compute recovery in some cases was due to control plane devices that are inline to execute the power operations on the Host machines. Datacenter technicians were required to reseat that infrastructure manually.

By 10:50 UTC on 27 December, >99.8% of the impacted VMs had recovered, with our team re-enabling Azure’s automated detection and remediation mechanisms. Some targeted remediation efforts were required for a remaining small percentage of VMs, requiring manual intervention to bring these back online. 

Azure Cosmos DB -

For Azure Cosmos DB accounts configured with availability zones, there was no impact, and the account maintained availability for reads and writes.

Impact on other Cosmos DB accounts varied depending on the customer database account regional configurations and consistency settings:  

  • Database accounts configured with availability zones were not impacted by the incident, and maintained availability for reads and writes. 
  • Database accounts with multiple read regions and a single write region outside South Central US maintained availability for reads and writes if configured with session or lower consistency. Accounts using strong or bounded staleness consistency may have experienced write throttling to preserve consistency guarantees until the South Central US region was either taken offline or recovered. This behavior is by design.  
  • Active-passive database accounts with multiple read regions and a single write region in South Central US maintained read availability, but write availability was impacted until the South Central US region was taken offline or recovered. 
  • Single-region database accounts in South Central US without Availability Zone configuration were impacted if any partition resided on the affected instances.

Azure SQL Database: 

For Azure SQL Databases configured with zone redundancy, there was no impact.

A subset of customers in this region experienced unavailability and slow/stuck control plane operations, such as updating the service level objective, for databases that are not configured as zone redundant. Customers with active geo-replication configuration were asked to consider failing out of the region at approximately 22:31 UTC.

Impact duration varied. Most databases recovered after Azure Storage recovered. Some databases took an extended time to recover due to the aforementioned long recovery time of some underlying VMs.

Azure Application Gateway: 

  • Application Gateway experienced issues with data path, control plane, and auto-scale operations, leading to service disruptions. Impact on Application Gateways varied depending on customer configuration:
  • Customers who deployed Application Gateways with zone redundancy may have experienced latency issues and overall degraded performance.
  • Customers who deployed Application Gateways to a single zone or did not specify zone info during deployment may have experienced data path loss if their deployments had instances in the affected zone.
  • Gateways with instances deployed in affected zone may have experienced failures or delays in configuration updates.
  • Gateways with instances deployed in affected zone may have experienced failures or delays in auto scale operations.

Azure Firewall: 

For Azure Firewalls deployed to all Availability Zones of the region, customers would not have experienced any data path impact. 

However, customers with an Azure Firewall deployed only to the impacted Availability Zone (physical zone AZ03), may have experienced some performance degradation – affecting the ability to scale out. Finally, customers attempting control plane operations (for example, making changes to Firewall policies/rules) may have experienced failures during this incident. Both of these impacts were experienced between 18:40 UTC on 26 December and 07:22 UTC on 27 December 2024.

Azure Synapse:  

Some users of Azure Synapse Analytics faced spark job execution failures in South Central US, Brazil South, and EastUS2. This impacted less than 1% of Synapse calls in those regions. Your logs may include one or more of the following errors that could be a result of this issue: “CLUSTER_CREATION_TIMED_OUT”, “FAILED_CLUSTER_CREATION”, “CLUSTER_FAILED_AFTER_RUNNING”. During this period, Azure Synapse could not provision on-demand compute due to failure to retrieve Management Group's ancestry for RBAC evaluations. The underlying storage for the SCUS instance of the ancestry data was impacted by this incident, which South Central US, Brazil South, and EastUS2 regions depend on. The data is replicated globally and regional failover attempts were made, but did not succeed due to a gateway error. The issue was resolved across all regions once South Central US region was recovered. 

How did we respond? 

  • 18:40 UTC on 26 December 2024 – Initial power event occurred which led to power loss in the affected data hall. 
  • 18:45 UTC on 26 December 2024 – Technicians from datacenter operations team engaged. 
  • 18:46 UTC on 26 December 2024 – Portal Communications started being sent to impacted subscriptions. 
  • 19:02 UTC on 26 December 2024 – Datacenter incident call began to support triaging and troubleshooting issues. 
  • 19:08 UTC on 26 December 2024 – Azure engineering teams joined a central incident call, to triage and troubleshoot Azure service impact. 
  • 20:13 UTC on 26 December 2024 – Power restoration assessed safe and began. 
  • 20:35 UTC on 26 December 2024 – Compute, Network, and Storage infrastructure began to recover. 
  • 20:54 UTC on 26 December 2024 – Communications published to our public status page.  
  • 20:56 UTC on 26 December 2024 – Power had been restored. Infrastructure recovery continued. 
  • 21:40 UTC on 26 December 2024 – 85% of the VMs impacted by underlying VHD availability recovered. 
  • 06:30 UTC on 27 December 2024 – Additional 13% of VMs impacted by VHD availability recovered. 
  • 08:30 UTC on 27 December 2024 – Ongoing mitigation of additionally impacted services. 
  • 13:00 UTC on 27 December 2024 – Mitigation to most affected services confirmed. 
  • 19:30 UTC on 27 December 2024 – Incident mitigation confirmed and declared.  

How are we making incidents like this less likely or less impactful? 

  • Datacenter response to return to utility power after ensuring battery health for UPS transition from generator (Completed).
  • We are reviewing the nature of the UPS battery failures in line with our global battery standards and maintenance procedures, to identify improvements to de-risk this class of issue across the fleet. (Estimated completion: February 2025)
  • Repairs to the offline failed utility line are in progress. (Estimated completion: February 2025)
  • The mitigation to bypass various checks during the bootstrap process have been applied to all impacted machines and are being evaluated and executed for other hardware configurations where needed. (Estimated completion: March 2025) 

How can customers make incidents like this less impactful? 

How can we make our incident communications more useful? 

You can rate this PIR and provide any feedback using our quick 3-question survey:

listopad 2024

13

Watch our 'Azure Incident Retrospective' video about this incident:

What happened?

Between 00:50 UTC and 12:30 UTC on 13 November 2024, a subset of Azure Blob Storage and Azure Data Lake Storage accounts experienced connectivity errors. The issue manifested as loss of access to Blob and Data Lake storage endpoints of the affected storage accounts, and subsequent unavailability of downstream services that depended on these storage accounts. Since many of the impacted storage accounts were used by other Azure services and major software vendor solutions, the customer impact was widespread. Although unavailable to access, the data stored in these storage accounts was not impacted during this incident. Impacted downstream services included:

  • Azure Storage: Impacted customers may have experienced name (DNS) resolution failures when interacting with impacted storage accounts in Australia East, Australia Southeast, Brazil South, Brazil Southeast, Canada Central, Canada East, Central India, Central US, East Asia, East US, East US 2, East US 2 EUAP, France Central, Germany West Central, Japan East, Japan West, Korea Central, North Central US, North Europe, Norway East, South Africa North, South Central US, South India, Southeast Asia, Sweden Central, Switzerland North, UAE North, UK South, UK West, West Central US, West Europe, West US, West US 2, West US 3.
  • Azure Container Registry: Impacted customers using the East US region may have experienced intermittent 5xx errors while trying to pull images from the registry.
  • Azure Databricks: Impacted customers may have experienced failures with launching clusters and serverless compute resources in Australia East, Canada Central, Canada East, Central US, East US, East US 2, Japan East, South Central US, UAE North, West US, and/or West US 2.
  • Azure Log Analytics: Impacted customers using the West Europe, Southeast Asia, and/or Korea Central regions may have experienced delays and/or stale data when viewing Microsoft Graph activity logs.

What went wrong and why?

Azure Traffic Manager manages and routes blob and data lake storage API requests. The incident was caused by an unintentional deletion of Traffic Manager profiles for the impacted storage accounts. These Traffic Manager profiles were originally part of an Azure subscription pool which belonged to the Azure Storage service. This original service was bifurcated to become two separate services, with one service that would eventually be deprecated. Ownership of the subscriptions containing the Traffic Manager profiles for storage accounts should have been assigned to the service that was continuing operation, which was missed. As such, the decommissioning process inadvertently deleted the Traffic Manager profiles under the subscription, leading to loss of access to the affected storage accounts. To learn more about Azure Traffic Manager profiles, see: .

How did we respond?

After receiving customer reports of issues, our team immediately engaged to investigate. Once we understood what had triggered the problem, our team initiated started to restore Traffic Manager profiles of the affected storage accounts. The recovery took an extended period of time since it required care reconstructing the Traffic Manager profiles while avoiding further customer impact. We started multiple workstreams in parallel, to drive both manual recovery and create automated steps to speed up recovery. Recovery was carried out in phases, with the majority of affected accounts restored by 06:24 UTC - and the last set of storage accounts recovered and fully operational by 12:30 UTC. Timeline of key events:

  • 13 November 2024 @ 00:50 UTC – First customer impact, triggered by the deletion of a Traffic Manager profile.
  • 13 November 2024 @ 01:24 UTC – First customer report of issues, on-call engineering team began to investigate.
  • 13 November 2024 @ 01:40 UTC – We identified that the issues were triggered by the deletion of Traffic Manager profiles.
  • 13 November 2024 @ 02:16 UTC – Impacted Traffic Manager profiles identified, and recovery planning started.
  • 13 November 2024 @ 02:25 UTC – Recovery workstreams started.
  • 13 November 2024 @ 03:51 UTC – First batch of storage accounts recovered and validated.
  • 13 November 2024 @ 06:00 UTC – Automation to perform regional recovery in place.
  • 13 November 2024 @ 06:24 UTC – Majority of recovery completed; most impacted accounts were accessible by this time.
  • 13 November 2024 @ 12:30 UTC – Recovery and validation 100% complete, incident mitigated. 

How are we making incidents like this less likely or less impactful?

  • We completed an audit of all the production service artifacts used by the Azure Storage resource provider. (Completed)
  • We created a new highly restrictive deployment approval process, as an additional measure to prevent unintended mutations like deletions. (Completed)
  • We are improving the process used to clean-up production service artifacts with built-in safety to prevent impact. (Estimated completion: December 2024)
  • We are enhancing our monitoring of outside-in storage traffic by making it more sensitive to smaller impacts and to validate connectivity and reachability for all endpoints of storage accounts. (Some services completed, all service will complete in December 2024)
  • We are expanding and completing the process of securing platform resources with resource locks, as an additional safety automation to prevent deletes. (Estimated completion: January 2025)
  • We will accelerate recovery times by refining restore points and optimizing the recovery process for production service artifacts. (Estimated completion: January 2025)
  • We will reduce the blast radius with service architectural improvements to improve the resiliency against issues related to traffic manager, and other upstream dependencies’, unavailability. (Estimated completion: March 2025)

How can customers make incidents like this less impactful?

  • Consider ensuring that the right people in your organization will be notified about any future service issues – by configuring Azure Service Health alerts. These can trigger emails, SMS, push notifications, webhooks, and more:
  • The impact times above represent the full incident duration, so are not specific to any individual customer. Actual impact to service availability varied between customers and resources – for guidance on implementing monitoring to understand granular impact:

How can we make our incident communications more useful?

You can rate this PIR and provide any feedback using our quick 3-question survey: