Troubleshooting Exhausted Connections in an AKS Cluster with Linux VMs
In this article, we will discuss the issue of an AKS cluster resulting in outages due to failing outgoing connections, specifically when running a cluster with 5 Linux VMs. We will cover the symptoms, key concepts, and provide a detailed troubleshooting guide to help you resolve this problem.
Symptoms
The primary symptom of this issue is seeing a large portion of outgoing connections being dropped or failing. This can result in a degraded or entirely unavailable AKS cluster, impacting the applications and services running on it.
Key Concepts
To understand and troubleshoot this issue, it's essential to familiarize yourself with the following key concepts:
- AKS (Azure Kubernetes Service)
- Linux VMs
- Outgoing connections
- Exhausted connections
Troubleshooting Guide
To troubleshoot this issue, follow these steps:
-
Check the AKS cluster's status and logs:
kubectl get nodes kubectl logs-n kube-system -
Inspect the Linux VMs' system logs for any connection or network-related errors:
journalctl -u networkd journalctl -u NetworkManager -
Review the Kubernetes pods and services to ensure they are configured correctly and not causing connection exhaustion:
kubectl get pods kubectl get services -
Check for any resource bottlenecks or performance issues in the AKS cluster:
kubectl top nodes kubectl top pods -
Analyze the AKS cluster's network policies and ensure they are not unintentionally blocking outgoing connections:
kubectl get networkpolicies -
Review the Azure network configuration and security rules to ensure they are not causing connection exhaustion:
az network nsg show --resource-group--name
In this article, we covered the issue of an AKS cluster resulting in outages due to failing outgoing connections on Linux VMs. By understanding the symptoms and key concepts, and following the troubleshooting guide, you should be able to identify and resolve this problem.