Azure Diagnostics

# Azure Diagnostics

> **AUTHORITATIVE GUIDANCE — MANDATORY COMPLIANCE** > > This document is the **official source** for debugging and troubleshooting Azure production issues. Follow these instructions to diagnose and resolve common Azure service problems systematically.

## Triggers

Activate this skill when user wants to: - Debug or troubleshoot production issues - Diagnose errors in Azure services - Analyze application logs or metrics - Fix image pull, cold start, or health probe issues - Investigate why Azure resources are failing - Find root cause of application errors - Troubleshoot App Service issues (high CPU, deployment failures, crashes, slow responses, TLS/custom domains) - Respond to prompts like "troubleshoot app service", "app service high CPU", or "app service deployment failure" - Troubleshoot Azure Function Apps (invocation failures, timeouts, binding errors) - Find the App Insights or Log Analytics workspace linked to a Function App - Troubleshoot AKS clusters, nodes, pods, ingress, or Kubernetes networking issues - Troubleshoot Azure VM connectivity issues (RDP/SSH failures, port 3389/22 timeouts, NSG or firewall blocking, credential resets) - Troubleshoot Azure Messaging SDK issues (Event Hubs, Service Bus connection failures, AMQP errors, message lock issues)

## Rules

1. Start with systematic diagnosis flow 2. Use AppLens (MCP) for AI-powered diagnostics when available 3. Check resource health before deep-diving into logs 4. Select appropriate troubleshooting guide based on service type 5. Document findings and attempted remediation steps 6. Route AKS incidents to the dedicated AKS troubleshooting document

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## Quick Diagnosis Flow

1. **Identify symptoms** - What's failing? 2. **Check resource health** - Is Azure healthy? 3. **Review logs** - What do logs show? 4. **Analyze metrics** - Performance patterns? 5. **Investigate recent changes** - What changed?

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## Troubleshooting Guides by Service

| Service | Common Issues | Reference | |---------|---------------|-----------| | **Container Apps** | Image pull failures, cold starts, health probes, port mismatches | [container-apps/](references/container-apps/README.md) | | **App Service** | High CPU, deployment failures, crashes, slow responses, TLS/custom domains | [app-service/](references/app-service/README.md) | | **Function Apps** | App details, invocation failures, timeouts, binding errors, cold starts, missing app settings | [functions/](references/functions/README.md) | | **AKS** | Cluster access, nodes, `kube-system`, scheduling, crash loops, ingress, DNS, upgrades | [AKS Troubleshooting](troubleshooting/aks/aks-troubleshooting.md) | | **Compute** | VM RDP/SSH connectivity, NSG/firewall blocks, credential resets, VM agent/tooling issues | [VM Connectivity Troubleshooting](troubleshooting/compute/vm-troubleshooting.md) | | **Messaging** | Event Hubs & Service Bus SDK errors, AMQP failures, message lock, connectivity | [Messaging Troubleshooting](troubleshooting/messaging/README.md) |

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## Routing

- Keep Container Apps and Function Apps diagnostics in this parent skill. - Route active AKS incidents, AKS-specific intake, evidence gathering, and remediation guidance to [AKS Troubleshooting](troubleshooting/aks/aks-troubleshooting.md). - Route Azure VM RDP/SSH connectivity, NSG/firewall, credential reset, and VM agent troubleshooting to [VM Connectivity Troubleshooting](troubleshooting/compute/vm-troubleshooting.md). - Route Azure Messaging SDK troubleshooting (Event Hubs, Service Bus) to [Messaging Troubleshooting](troubleshooting/messaging/README.md).

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## Quick Reference

### Common Diagnostic Commands

```bash # Check resource health az resource show --ids RESOURCE_ID # View activity log az monitor activity-log list -g RG --max-events 20 # Container Apps logs az containerapp logs show --name APP -g RG --follow # Function App logs (query App Insights traces) az monitor app-insights query --apps APP-INSIGHTS -g RG \ --analytics-query "traces | where timestamp > ago(1h) | order by timestamp desc | take 50" ```

### AppLens (MCP Tools)

For AI-powered diagnostics, use: ``` mcp_azure_mcp_applens intent: "diagnose issues with <resource-name>" command: "diagnose" parameters: resourceId: "<resource-id>"

Provides: - Automated issue detection - Root cause analysis - Remediation recommendations ```

### Azure Monitor (MCP Tools)

For querying logs and metrics: ``` mcp_azure_mcp_monitor intent: "query logs for <resource-name>" command: "logs_query" parameters: workspaceId: "<workspace-id>" query: "<KQL-query>" ```

See [kql-queries.md](references/kql-queries.md) for common diagnostic queries.

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## Check Azure Resource Health

### Using MCP

``` mcp_azure_mcp_resourcehealth intent: "check health status of <resource-name>" command: "get" parameters: resourceId: "<resource-id>" ```

### Using CLI

```bash # Check specific resource health az resource show --ids RESOURCE_ID

# Check rec