Monitoring Your Azure Kubernetes Service (AKS) Clusters

Effective monitoring is crucial for maintaining the health, performance, and security of your Azure Kubernetes Service (AKS) deployments. This documentation provides a comprehensive guide to the tools and strategies available for monitoring your AKS clusters.

By leveraging Azure's integrated monitoring services, you can gain deep insights into your cluster's resource utilization, application performance, and potential issues.

Azure Monitor

Azure Monitor is a unified observability solution that helps you maximize the availability and performance of your cloud and on-premises environments. For AKS, Azure Monitor provides a centralized platform for collecting, analyzing, and acting on telemetry data.

Key features include:

  • Log Analytics: For storing and querying log data.
  • Metrics: For collecting numerical data over time.
  • Application Insights: For deep application performance monitoring.
  • Alerts: To notify you of critical events.

You can integrate Azure Monitor directly with your AKS clusters to streamline your monitoring efforts.

Container Insights

Container Insights is an Azure Monitor solution that provides performance monitoring for container workloads deployed to AKS. It automatically detects your existing Azure containers and monitors their performance over time.

With Container Insights, you can:

  • Collect and analyze logs from AKS clusters.
  • Monitor resource utilization (CPU, memory, network) of nodes and pods.
  • Visualize cluster health and performance using interactive dashboards.
  • Detect configuration changes and failures.

To enable Container Insights, you typically deploy the solution to your Log Analytics workspace and configure the agent on your AKS cluster.

Note: Ensure your AKS cluster has network connectivity to the Log Analytics workspace.

Logging

Comprehensive logging is essential for debugging and auditing. AKS integrates with Azure Monitor Logs (via Log Analytics) to collect various types of logs:

  • Container Logs: Standard output and error streams from your application containers.
  • Kubelet Logs: Logs from the Kubelet agent running on each node.
  • Kube-proxy Logs: Logs from the network proxy.
  • Control Plane Logs: Logs from Kubernetes API server, scheduler, controller manager, and etcd.

You can use Kusto Query Language (KQL) in Log Analytics to query these logs effectively.


# Example KQL query to find recent errors in container logs
ContainerLog
| where TimeGenerated > ago(1h)
| where LogMessage contains "error"
| project TimeGenerated, PodName, LogMessage

Metrics

Azure Monitor collects performance metrics from your AKS cluster, providing insights into resource usage and performance trends. These metrics are available at the cluster, node, and pod levels.

Common metrics include:

  • CPU usage (%)
  • Memory usage (%)
  • Network in/out (bytes)
  • Disk I/O

These metrics can be visualized in Azure Monitor's Metrics Explorer or used to trigger alerts.

Alerts

Configure alerts to be notified proactively when specific conditions are met within your AKS cluster. Alerts can be based on metrics, log queries, or activity logs.

Common alert scenarios for AKS include:

  • High CPU or memory utilization on nodes or pods.
  • Application errors detected in logs.
  • Kubernetes pod restarts or failures.
  • Cluster health status changes.

Alerts can trigger actions such as sending emails, triggering webhooks, or running automation runbooks.

Dashboards

Create custom dashboards in Azure Monitor or Azure Portal to consolidate key monitoring information. Dashboards provide a single pane of glass for visualizing metrics, logs, and alerts related to your AKS deployments.

Container Insights offers pre-built dashboards that provide a quick overview of your cluster's health and performance.

Troubleshooting

When issues arise, the collected logs and metrics are invaluable for diagnosing the root cause. Use Log Analytics to filter logs by pod, namespace, or time, and correlate events across different components.

Consider the following steps during troubleshooting:

  • Check pod status and events.
  • Examine container logs for application errors.
  • Monitor node resource utilization.
  • Review Kubernetes audit logs for security-related events.
Tip: Leverage Azure's Kubernetes diagnostic tools and documentation for in-depth troubleshooting guides.

Best Practices

  • Enable Container Insights: Start with Container Insights for an out-of-the-box monitoring experience.
  • Define Meaningful Alerts: Set up alerts for critical thresholds to ensure timely intervention.
  • Centralize Logging: Use Log Analytics to store and analyze logs from all your AKS clusters.
  • Regularly Review Dashboards: Make it a habit to check your monitoring dashboards.
  • Tag Resources: Use Azure tags to categorize and filter monitoring data.
  • Monitor Costs: Be mindful of data ingestion and retention costs in Log Analytics.