Monitor Azure Virtual Machines
This document provides comprehensive guidance on monitoring your Azure Virtual Machines (VMs) to ensure optimal performance, availability, and cost-effectiveness. Effective monitoring is crucial for identifying and resolving issues proactively, understanding resource utilization, and making informed decisions about your infrastructure.
Key Monitoring Tools and Services
Azure offers a suite of integrated services to monitor your VMs:
- Azure Monitor: The foundational service for collecting, analyzing, and acting on telemetry from your Azure and on-premises environments. It encompasses Application Insights and Log Analytics.
- Azure Resource Health: Helps you diagnose and recover from service problems that affect your Azure resources, including VMs.
- Azure Advisor: Provides personalized recommendations to help you optimize your Azure resources for performance, security, cost, and reliability.
- Azure Activity Log: Records subscription-level events that occur in your Azure subscription, such as resource creation or deletion.
Monitoring with Azure Monitor
Azure Monitor is the primary tool for deep VM insights. It collects metrics and logs, allowing you to visualize performance, set alerts, and analyze trends.
Metrics
Metrics are numerical values that describe some aspect of a system at a particular time. For VMs, common metrics include:
- CPU utilization
- Disk I/O (read/write operations, latency)
- Network in/out
- Memory usage (requires guest agent installation)
You can view these metrics in the Azure portal for individual VMs or aggregate them across multiple resources using metrics explorer.
Logs
Logs provide detailed information about events and operations occurring within your VMs and Azure environment. Azure Monitor uses Log Analytics as its log management and analysis engine.
- Host-level logs: Metrics and events from the Azure infrastructure supporting your VM.
- Guest OS logs: Performance counters, event logs (Windows), syslog (Linux), and custom application logs collected by the Azure Monitor agent or Log Analytics agent.
Querying logs with the Kusto Query Language (KQL) allows for powerful diagnostics and troubleshooting.
Alerting
Configure alerts based on metrics or log queries to notify you when specific conditions are met. Alerts can trigger actions like sending an email, running a webhook, or creating an incident in an IT service management tool.
Example Alert Rule: Trigger an alert when CPU utilization exceeds 80% for 15 minutes.
-- Example KQL query for high CPU
Perf
| where ObjectName == "Processor" and CounterName == "% Processor Time" and InstanceName == "_Total"
| summarize AggregatedValue = avg(CounterValue) by bin(TimeGenerated, 5m), Computer
| where AggregatedValue > 80
Using Azure Resource Health
Resource Health provides information about the current and past service health of your Azure resources. It can alert you to issues originating from the Azure platform that may affect your VM's availability.
Benefits:
- Real-time status updates for your VMs.
- Root cause analysis of platform-level issues.
- Guidance on remediation steps.
Best Practices for VM Monitoring
Key Areas to Monitor:
- Performance Bottlenecks: Identify high CPU, memory, disk, or network usage.
- Availability: Monitor VM uptime and response times.
- Security: Integrate with Azure Security Center for security monitoring and threat detection.
- Costs: Track resource utilization to identify opportunities for cost optimization.