What is the best practice for achieving the High availability of applications running on Azure VM having web tier and DB tier?

Achieving high availability for applications running on Azure VMs with web and database tiers requires a combination of best practices and tools. Here are some recommended best practices:

1. Use Availability Sets: Availability Sets are a feature in Azure that enables you to group two or more VMs within a set to ensure that your applications remain available in the event of a hardware or software failure. By distributing VMs across multiple fault domains, Azure ensures that your application remains available even if one of the fault domains experiences a failure.
2. Use Load Balancers: Azure Load Balancer is a service that distributes incoming traffic across multiple VMs, ensuring that traffic is routed to healthy instances. By using load balancers, you can distribute traffic evenly across multiple instances and achieve high availability for your applications.
3. Use Managed Disks: Azure Managed Disks is a service that provides highly available and durable storage for your VMs. By using Managed Disks, you can ensure that your data is replicated across multiple disks and multiple fault domains, providing high availability for your data.
4. Use Azure Site Recovery: Azure Site Recovery is a disaster recovery solution that provides continuous replication of your VMs and data to a secondary location, enabling you to failover to the secondary location in the event of a disaster. By using Azure Site Recovery, you can ensure that your applications remain available in the event of a disaster.
5. Use Azure SQL Database: Azure SQL Database is a managed database service that provides high availability and disaster recovery for your databases. By using Azure SQL Database, you can ensure that your databases remain available even in the event of a failure.
6. Use Virtual Machine Scale Sets: Virtual Machine Scale Sets enable you to automatically scale your VMs based on demand, ensuring that your applications remain available even during peak periods of activity.

Conclusion:

Achieving high availability for applications running on Azure VMs with web and database tiers requires a combination of best practices and tools. By using availability sets, load balancers, managed disks, Azure Site Recovery, Azure SQL Database, and Virtual Machine Scale Sets, you can ensure that your applications remain available and provide a seamless experience to your users.