Azure Kubernetes Services troubleshooting documentation

Welcome to Azure Kubernetes Services troubleshooting. These articles explain how to determine, diagnose, and fix issues that you might encounter when you use Azure Kubernetes Services. In the navigation pane on the left, browse through the article list or use the search box to find issues and solutions.

Learn how to use AKS with these quickstarts, tutorials, and samples

How-To Guide

• AKS documentation

Troubleshoot create operations

How-To Guide

• Basic troubleshooting
• K8SAPIServerConnFailVMExtensionError error (51)
• K8SAPIServerDNSLookupFailVMExtensionError error (52)
• MissingSubscriptionRegistration error
• OutboundConnFailVMExtensionError error (50)
• RequestDisallowedByPolicy error
• SubnetIsFull error
• SubscriptionRequestsThrottled error (429)

Troubleshoot upgrade operations

How-To Guide

• Upgrade fails because of NSG rules
• PodDrainFailure error
• PublicIPCountLimitReached error
• QuotaExceeded error
• SubnetIsFull error during an upgrade
• Kubernetes 1.16 upgrades fail using node labels
• Upgrade issues with Gen2 VMs on Windows AKS cluster

Troubleshoot delete operations

How-To Guide

• CannotDeleteLoadBalancerWithPrivateLinkService error
• InUseRouteTableCannotBeDeleted error
• LoadBalancerInUseByVirtualMachineScaleSet error
• PublicIPAddressCannotBeDeleted error
• RequestDisallowedByPolicy error
• TooManyRequestsReceived error

Troubleshoot scale operations

How-To Guide

• Common issues with running or scaling large AKS clusters
• Failed to fix node group sizes

Troubleshoot start operations

How-To Guide

• Basic troubleshooting
• K8SAPIServerConnFailVMExtensionError error (51)
• K8SAPIServerDNSLookupFailVMExtensionError error (52)
• OutboundConnFailVMExtensionError error (50)

Troubleshoot node not ready

How-To Guide

• Basic troubleshooting
• Custom script extension errors
• Expired certificates
• Node not ready after being healthy
• Node not ready but then recovers

Cannot connect to application hosted on AKS cluster

How-To Guide

• Basic troubleshooting
• Custom NSG blocks traffic
• Failures in the "az aks command invoke" command
• Get and analyze HTTP response codes
• Intermittent timeouts or server issues

Cannot connect to AKS cluster

How-To Guide

• Basic troubleshooting
• Client IP address can't access API server
• Config file isn't available when connecting
• Tunnel connectivity issues
• User can't get cluster resources

Data collection guide

How-To Guide

• Capture real-time system insights from cluster
• Capture TCP dump from Linux node
• Capture TCP dump from Windows node
• Capture TCP packets from pod

Troubleshoot AKS cluster performance issues

How-To Guide

• Identify high CPU consuming containers
• Identify memory saturation in AKS clusters

Troubleshoot Azure Linux container host issues

How-To Guide

• Troubleshoot common issues with Azure Linux container hosts on AKS