Ensuring High Availability: Best Practices for Azure-hosted Applications
Tags: azure, cloud, beginners
Published: 2023-06-03 14:36:37

In today's digitally-driven world, where applications play a pivotal role in powering businesses, ensuring the high availability of applications hosted in Azure has become more critical than ever before. The importance of high availability cannot be overstated, as it directly impacts revenue, customer satisfaction, brand reputation, and even regulatory compliance. 

In this article, we delve into the significance of ensuring high availability for applications hosted in Azure and highlight the tangible benefits that organizations can reap by investing in a robust and resilient infrastructure. By understanding the value that high availability brings to the table, businesses can make informed decisions to protect their applications and keep a competitive advantage in a highly increasing demanding market.

High availability is a critical requirement for many applications, especially those that are mission-critical or that serve a large number of users. High availability refers to the design and implementation of systems or applications that are continuously operational and accessible, with minimal downtime and disruptions.

The recommended practises for ensuring your Azure-hosted application stays highly available are listed below.

**Use Azure Availability Zones**

Availability Zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Deploying resources across multiple Availability Zones can provide additional fault tolerance, ensuring that your application remains available even in the event of a datacenter-level failure.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/bealazs32gcxb7uy56oj.png)

**Use Azure Load Balancer**

Load balancing can help to improve the availability of your application by distributing traffic across multiple instances of your application. This can help to improve performance and reduce the impact of failures on individual instances. In addition, Azure Load Balancer offers health probes, which can be used to monitor the health of application instances and instantly remove any unhealthy ones from the load balancing pool.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/b91iuvlxvh2llvofqtob.png)

**Use Azure Traffic Manager** 

Azure Traffic Manager is a DNS-based traffic load balancer that can be used to distribute traffic to your applications hosted in Azure. Traffic Manager uses a variety of methods to ensure that your applications are always available, including:

- Health monitoring: Traffic Manager monitors the health of your application endpoints and automatically routes traffic away from unhealthy endpoints.

- Load balancing: Traffic Manager distributes traffic across your application endpoints based on a variety of factors, including availability, performance, and user location.

- Geo-replication: Traffic Manager can be used to create a global network of application endpoints that are automatically routed to users based on their geographic location.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/byh930ynvlkti8260igm.png)

**Use Azure Functions and Logic Apps**

Azure Functions and Logic Apps offer serverless computing capabilities for running business logic or processes. You may benefit from automated scaling and fault tolerance by creating your application with serverless architecture. Functions and Logic Apps can be deployed across different regions or Availability Zones to ensure high availability and to mitigate the effect of any localised failures.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/tvqa0eohd8fspx1lhhkk.png)

**Implement Azure Backup and Site Recovery**

Azure Backup and Azure Site Recovery are critical disaster recovery and data protection services. Azure Backup performs frequent backups of your application's data, ensuring that essential information can be restored in the event of inadvertent deletions or data corruption. Azure Site Recovery allows for the replication and failover of complete apps or virtual machines to a separate Azure region, enabling for disaster recovery to be smooth.


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/78gko69g6yy1l6lvsus8.png)

**Here are some additional tips for ensuring the high availability of your Azure application:**

- Use a reliable hosting provider: Azure is a reliable hosting provider, but it is important to choose a reputable hosting provider that has a good track record of uptime.

- Use a load balancer: A load balancer can help to distribute traffic across multiple instances of your application, which can help to improve performance and reduce the impact of failures on individual instances.

- Use a content delivery network (CDN): A CDN can help to improve the performance of your application by caching static content closer to your users. This can help to reduce the load on your application servers and improve the overall user experience.

- Back up your data regularly: It is important to back up your data regularly so that you can restore it in the event of a failure. Azure offers a number of backup options, so you can choose the option that best meets your needs.

- Monitor your application: It is important to monitor your application to ensure that it is performing as expected. This will help you to identify and address any issues that could impact the availability of your application.

By following these tips, you can help to ensure that your Azure application is highly available and that your users can always access it.

Please note that the images used in this blog post are sourced from various websites on the internet and do not belong to me.