Azure provides a wide variety of services and provides seamless integration with other cloud providers. It offers a lot of features for making your applications resilient. This blog will look at how you can design resilient and reliable cloud native Azure applications.
Imagine this scenario. Your organization has recently shifted to the cloud platform. And, you no longer have to follow the traditional record-keeping or project management methods. The employees were trained to adapt to the digital scenario.
However, one day your cloud application suddenly stops working. Your employees are not able to access their files. They fail to send emails. And, you don’t have any backup of your files available offline.
What happened here?
Your cloud system lacks the resiliency to continue operating, irrespective of failures. However, most popular cloud systems like Azure have inbuilt resilience to failures.
In this blog, let’s understand how to design resilient Azure applications.
What is the Meaning of Resilient Azure Applications?
Resiliency shows the ability of Azure applications to recover quickly from failure. Resilient applications minimize data loss and downtime of your system. In a business environment, every minute is crucial. Every effort is important, and you need to ensure a resilient azure setup for your organization.
In the next section, let’s understand the top strategies to design resilient Azure applications.
Top 8 Ways to Design Resilient/Reliable Azure Applications
The top 8 ways to design a resilient Azure application are using availability zones properly, understanding the subscription landscape, determining the correct virtual machine, decoding the scalability factor, etc.
Let’s explore this in detail.
Use Availability Zones the Right Way
Azure has multiple availability zones physically located in one or more locations within every Azure region. It is also tolerant of local failures.
You can use multiple availability zones to ensure that your system recovers well from failures. Availability zone can optimize your applications within a region and make them fault-proof and tolerable. However, you need to consider the additional costs like networking, data, and Azure site recovery services. Also, make sure that the dependencies between the architecture should not be shared for effective functioning.
Put in Place Business Continuity Disaster Recovery Strategy (BCDR)
Ensure that you brainstorm the different scenarios your Azure application can face. With BCDR strategy, you can understand how your applications respond in a disaster situation like the loss of an essential service or regional outages.
Ensure that you categorize your application components into groups like must protect, nice to protect, and can be rebuilt/lost.
Consider the Scalability Factor
Have you designed your Azure application to scale out? Usually, Azure provides elastic scalability. You need to ensure that all the applications and individual components can be scaled out easily. However, customers forget to write the scale-in rules and only focus on the scale-out rules. Scale in rules is essential to cut down your cost of operation.
Understand the Azure Subscription Landscape
Here, you have to decide if you have the required quota or limit under the Azure subscription models. Carefully understand the Azure capacity and see how the components are organized across multiple subscriptions.
For instance, Azure has three pricing tiers with different limits and capacities. You can use the free tier for small development projects. If you go for the Basic tier, you get dedicated computing resources. For highly available query workloads, you can use up to three replicas. For higher production workloads, you need a standard tier with multiple tiers.
Use the Right Azure Load Balancer
Ensure that you select the standard load balancer for your Azure framework. Preferably, select the standard SKU. With a standard SKU, you can better handle zone resiliency and zone availability. Even if one of your zones stops working, there won’t be any impact on the SKU. Hence, the load balancer will make your Azure applications zone and region resilient.
Second, use the outbound rules to prevent connection failures. Connection failures can occur when there is a SNAT port exhaustion. However, outbound rules are more beneficial for small to mid-size deployment.
Third, use at least two instances in your Azure backend. The chances of failure are more with a single instance.
Assess the Storage Patterns
Some storage strategies like using the read-access geo-redundant storage (RA-GRS), using managed disks, and creating a backup queue increase the resiliency of your Azure applications.
First, the (RA-GRS) ensures that your data gets stored in the secondary region and the access is read-only.
Second, managed disks increase the reliability of a virtual machine in the availability zone. Proper isolation between the disks ensures no single point of failure.
Third, your application can easily handle any outages with a backup queue. In case of a storage outage, the backup queue is retrieved to restart the application.
Determine the Correct Virtual Machine
There are definite ways to use a virtual machine to increase the resiliency of your Azure applications. First, don’t run Azure on a single virtual machine. It is not capable of handling unplanned maintenance activities. Instead, use multiple virtual machines in an availability set.
Second, select a definite availability set while provisioning the virtual machine. If you don’t specify the availability set before, the load balancer cannot properly route the traffic.
Third, ensure that you choose the right virtual machine size based on your unique performance requirements. The VM size should ideally match your on-premise servers. Then, test the performance of the actual workload about disk IOPS, memory, CPU, and more. In this way, you can ensure the ideal behavior of your application in the cloud.
Fourth, ensure that you have the diagnostics logs enabled. These include infrastructure logs and basic health metrics. With boot diagnostics, you can easily identify the problem if your virtual machine gets into a non-bootable state.
Final Thoughts:
Overall, as more and more organizations shift to the cloud, it’s necessary to design resilient Azure applications. Resilience makes your application withstand any failure, and you can continue working without interruptions.
Ensure that you have multiple availability zones, implement a business continuity disaster recovery strategy (BCDR), decode the Azure subscription landscape, and use the right load balancer. Assess the performance of your Azure applications in different scenarios and make them resilient to each of these.
