Azure Troubleshooting Guide

MSDN Documentation - Support

Troubleshooting Common Azure Issues

This guide provides solutions and workarounds for frequently encountered problems when using Microsoft Azure services. We cover a range of scenarios, from connectivity issues to performance bottlenecks.

1. Virtual Machine (VM) Connectivity Problems

If you are unable to connect to your Azure VM via RDP or SSH, follow these steps:

1.1 Check Network Security Groups (NSGs)

Ensure that your NSGs allow inbound traffic on the necessary ports (e.g., RDP port 3389 for Windows, SSH port 22 for Linux) from your IP address or network range.

# Example NSG rule for SSH
Inbound rule:
Priority: 100
Source: Any
Source port ranges: *
Destination: Any
Destination port ranges: 22
Protocol: TCP
Action: Allow

1.2 Verify Public IP Address Assignment

Confirm that the VM's network interface has a public IP address associated with it, or that it is accessible via a Load Balancer with a public frontend IP.

1.3 Use Azure Network Watcher

Network Watcher provides tools like Connection Troubleshoot and IP Flow Verify to diagnose connectivity issues. You can find it in the Azure portal under "Network Watcher".

Tip: If you've recently made changes to NSGs or firewall rules, always re-verify them after any connectivity issues arise.

2. Application Deployment Failures

Deployment issues can stem from various sources, including incorrect configuration, insufficient permissions, or service limitations.

2.1 Review Deployment Logs

Always check the deployment logs for detailed error messages. These logs are accessible through the Azure portal, Azure CLI, or Azure PowerShell.

# Example using Azure CLI
az deployment group list --resource-group myResourceGroup --output table

2.2 Check Resource Quotas and Limits

Ensure you haven't exceeded any subscription or service quotas. You can view your quotas in the Azure portal under "Usage + quotas".

2.3 Validate Service Principal Permissions

If using a Service Principal for deployments, verify that it has the necessary role assignments (e.g., Contributor) on the target resource group or subscription.

Warning: Granting excessive permissions to Service Principals can be a security risk. Follow the principle of least privilege.

3. Performance Degradation

Slow application performance in Azure can be challenging to diagnose. Here are common areas to investigate.

3.1 Monitor Azure Metrics

Utilize Azure Monitor to track key metrics for your services, such as CPU utilization, memory usage, network I/O, and disk latency.

3.2 Optimize Database Queries

Inefficient database queries are a frequent cause of performance issues. Use tools like SQL Server Management Studio (SSMS) or Azure Data Studio to analyze query plans and identify bottlenecks.

3.3 Scale Resources Appropriately

Consider scaling up (increasing instance size) or scaling out (adding more instances) your resources based on your monitoring data. Auto-scaling can be configured for many Azure services.

Good Practice: Implement consistent monitoring and alerting to proactively identify performance issues before they impact users.

4. Authentication and Authorization Errors

Problems with users or applications accessing Azure resources.

4.1 Azure Active Directory (Azure AD) Configuration

Verify user assignments, application registrations, and consent grants in Azure AD. Ensure that the correct authentication flows are being used.

4.2 Role-Based Access Control (RBAC)

Double-check that users and service principals have been assigned the appropriate RBAC roles with the necessary permissions to perform their actions.

Error Scenario: A common RBAC error is trying to access a resource without the "Reader" role or higher, even for read-only operations.

5. Storage Access Issues

Problems related to accessing Azure Storage (Blob, File, Queue, Table).

5.1 Shared Access Signature (SAS) Validity

Ensure that SAS tokens are correctly formatted, not expired, and have the appropriate permissions granted.

5.2 Firewall and Network Rules

Check if Azure Storage firewalls are blocking access from your client's IP address or virtual network. Ensure that "trusted Microsoft services" are allowed if applicable.

For more in-depth troubleshooting, please refer to the specific documentation for each Azure service.

Last updated: October 26, 2023