Azure SQL HADR

✅High Availability and Disaster Recovery (HADR) in Azure SQL: here’s how to set it up right

High Availability & Disaster Recovery in Azure SQL: Best Practices for 2025. Discover how to properly set up HADR in Azure SQL. Learn about failover groups, Always On, monitoring, and how to minimize downtime.

Introduction

In an always-on economy, data loss is no longer an option. Customers and users expect constant availability of applications and systems. A strong High Availability and Disaster Recovery (HADR) strategy is crucial to minimize risk and meet compliance requirements. Microsoft Azure offers powerful, integrated solutions for various SQL Server workloads for this purpose.

In this blog, we explain how to optimally set up HADR in Azure SQL – tailored to your architecture, workloads and organizational goals.

What is HADR in Azure SQL?

HADR combines:

• High Availability (HA): systems remain available even during outages.

• Disaster Recovery (DR): systems can recover quickly after a major disruption or disaster.

Azure provides native support for HADR, tailored to the type of SQL solution you use:

• Azure SQL Database (PaaS)

• Azure SQL Managed Instance (PaaS+)

• SQL Server on Azure Virtual Machines (IaaS)

Options by deployment model

🔹 1. Azure SQL Database

• Auto-failover groups for multi-region redundancy

• Active geo-replication for readable secondary databases

• SLA up to 99.995% availability

🔹 2. Azure SQL Managed Instance

• Zone redundant configuration for availability zones

• Failover groups between regions with geo-replication

🔹 3. SQL Server on Azure VM

• Always On Availability Groups (synchronous/asynchronous)

• Integration with Azure Site Recovery for DR

• Premium SSDs for storage redundancy

Best practices for implementation

1. Define RTO and RPO

   • Recovery Time Objective: how fast should your recovery be?

   • Recovery Point Objective: how much data can you lose?

2. Choose the right HADR strategy per workload

   • Critical applications → Always On AGs

   • Mid-tier workloads → Failover groups of geo-replication

3. Test regularly

   • Perform quarterly failover tests

   • Automate DR test scenarios with Azure DevOps

4. Monitor proactively

   • Use Azure Monitor, Log Analytics and SQL Insights

   • Configure alerts for replica latency, failover status, etc.

5. Create runbooks & documentation

   • Establish procedures for failover, DR verification and rollback

Common mistakes (the ones you want to avoid)

• ❌ Implement only HA or DR, not both

• ❌ Relying on default settings

• ❌ No testing, no alerts, no monitoring

• ❌ No established ownership within teams

🎯 Call to Action

🔍 Want to know if your current SQL environment can withstand failure or data loss? Get advice from our Azure experts or schedule a quick scan directly atinfo@improfs.nl. Or you can comment below!