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Azure vs AWS resilience

IaaS Resilience, which cloud platform is better? Azure or AWS?

Azure vs AWS IAAS Resilience

Now this blog post is only going to cover the two largest cloud providers, Microsoft’s Azure and Amazon’s AWS and only focusing on Infrastructure as a Service (Azure VMs for Azure, and EC2 for AWS) offerings they both provide, but with a bit of a deep dive in to the way they both provide resilience. Also with some architecture best practices to ensure your infrastructure and furthermore your applications remains available in the event of failure so that you can still provide applications to your user base and more importantly to your end customers. When designing your cloud IaaS deployments knowing how best to architect for high availability and resilient infrastructure is required, so knowing the in’s and outs of the major cloud providers is a must.

In this first part of a multiple blog overview we will cover off both AWS and Azure’s datacentre construction.

Azure and AWS Data Centre Comparison

Let’s start to look at how they each construct their data centres and provide you with their platforms for your Infrastructure as a Service deployments.

AWS Availability Zones and Regions

AWS Datacentres

First off the bat, let’s see how AWS setup their Datacentres. AWS has 69 Availability Zones dispersed over 22 geographic regions throughout the world (as of August 2019, but we can expect this number to grow as they continue to expand.)

AWS Availability Zones

Amazon Web Services Regions

Each AWS region is separated by geographic location and are totally independent from one another and are also made up of multiple AWS availability zones. Wikileaks actually released the locations of each AWS datacentre (some are AWS owned others are co-located datacentres). This isolation between regions is provided by completely separate infrastructure, that includes cooling, power and water supply. Every AWS region will have a minimum of two availability zones and each Availability Zone will have a minimum of one datacentres within each AZ, with connectivity between each datacentre within the AWS region having redundant low latency network connections between them.

What is an AWS Region?

In the picture above I have focused on the Sydney Australia AWS Region, which is comprised of three availability zones, multiple data centres (thanks to our wikileaks friends we know there are 8 in the Sydney region) and each with high bandwidth, low latency private redundant fibre connections which allows synchronous replication of services between each AZ.

So what is an AWS Availability Zone?

So what is an Availability Zone? Well by AWS own definition an ‘Availability Zones are the core of our infrastructure architecture and they form the foundation of AWS’s and customers’ reliability and operations. Availability Zones are designed for physical redundancy and provide resilience, enabling uninterrupted performance, even in the event of power outages, Internet downtime, floods, and other natural disasters.’ As stated before each AZ is made up of one or more datacentres but are logically grouped as one datacentre (availability zone) for all intents and purposes.

Having numerous Regions with multiple availability zones all with isolation and fast reliable network connectivity between them provides you with great fault tolerance and stability for your EC2 instances.

Azure and AWS Resilience Comparison

Regions25 regions as of 2021 with plans to expand60 regions as of 2021 with plans to expand
Availability Zones82 Availability Zones as of 202162 Azure regions have 160+ data centers in more than 60 regions
Service Level Agreement (SLA)Offers SLAs for most services, with a 99.99% uptime guarantee for some servicesOffers SLAs for most services, with a 99.99% uptime guarantee for some services
Disaster RecoveryOffers disaster recovery solutions for various scenarios such as site failure, regional disasters, and data lossOffers disaster recovery solutions for various scenarios such as site failure, regional disasters, and data loss
FailoverProvides automatic failover for many servicesProvides automatic failover for many services
Backup and RestoreOffers backup and restore solutions for various servicesOffers backup and restore solutions for various services
Load BalancingOffers load balancing services to distribute traffic across instancesOffers load balancing services to distribute traffic across instances
Auto ScalingProvides auto scaling to automatically adjust resources based on demandProvides auto scaling to automatically adjust resources based on demand

It’s worth noting that both AWS and Azure have robust resilience and uptime features, with both offering SLAs and disaster recovery solutions for various scenarios. AWS has more regions and availability zones, while Azure has a larger number of data centers overall. Both providers also offer automatic failover, backup and restore solutions, load balancing, and auto scaling features.

Azure Regions and Availability Zones

Cloud Regions

 Up until recently Availability Zones were not available within Microsoft Azure, but they have recently just come to the party (Availability Zones are currently not available in Australia, but we have four Azure Regions. The first Australian Region to offer Azure Availability Zones will be Sydney with commissioning of this AZ slated for some time in 2020). Previously Microsoft thought  multiple regions was better for their cloud environments over the AWS AZ model, but there are limitations with just using regions. 

The biggest issue with a region only approach is that the network between each region and the large distance between them would only allow asynchronous replication. This translates to data discrepancies as it was impossible to achieve a recovery point objective of zero which means possible data loss should an Azure region have an outage and you need to fail over your application and services. Now dependent on what business you are in this loss of data maybe not such a big problem, but if for example you are a bank, where a loss of 1 millisecond of data could contain millions of dollars of lost transactions that would be a huge problem. Luckily for us, Microsoft is rapidly building more datacentres and availability zones

Microsoft Azure Regions

Microsoft has currently at the time of writing this article 54 Azure regions available worldwide and is available in 140 countries. An Azure region is very similar to an AWS region, being that they are sets of datacentres that are connected with a low latency network between them. Microsoft do have selected Region pairs, depending on the storage replication you choose, your data will be asynchronously replicated to the closest available region. (For example, if your main Azure Region is Melbourne, your data can be replicated to the Sydney Region).

Microsoft Azure Availability Zones

Microsoft’s Azure Availability Zones are being rolled out over the next few years, so we can expect them to have the same resiliency as AWS for your cloud Azure VM deployments. The Azure AZs are unique physical locations and have independent power, cooling and networking from each other, with the physical separation providing you with protection from datacentre failure. Azure Regions and Availability Zones will provide you with a reliable, resilient and expanding platform for you to utilise for your cloud virtual machines.

So what are the differences between Azure and AWS?

Just focusing on what is discussed above, we can surmise the following;

  • Microsoft Azure currently has 54 regions versus AWS’s 22. Depending where your user or client base is, and to ensure quick response times of your infrastructure, Microsoft’s Azure maybe the only choice.
  • Microsoft have more regions closer to one another than AWS. (In Australia for example, we have four Azure Regions (but not Availability Zones as yet) compared to AWS only having the one). If for example AWS had a major outage that caused an issue to effect their whole Sydney Region, then you could possibly failover to Singapore, but expect lower performance due to the increased distance and latency (could be a problem if you have data sovereignty and need to keep your data within the Australian boundary) compared to Microsoft having four possible regions to utilise should a region have  major failure. (should be noted here that two of the Australia Regions (Central 1 and 2) are only approved for use by Defense, Government and Banking,  if your business does not fall under this category then you will only be able to use either Melbourne or Sydney)
  • AWS has more availability zones per region currently than Microsoft does, but Microsoft plan to roll out the Availability Zones as quickly as they can, so expect them to eventually have the same construct as AWS. Of course they have more regions so eventually they will over take AWS in this number.

All this alludes to two very competitive cloud vendors both trying to convince you to use their services, we really are spoilt for choice.

Azure and AWS Regions Comparison

Availability Zones69 zones in 22 regionsAvailability zones currently being rolled out
Regions22 regions54 regions
Virtual Machines (VMs)Elastic Compute Cloud (EC2)Azure Virtual Machines
Load BalancingElastic Load Balancer (ELB)Azure Load Balancer
StorageSimple Storage Service (S3)Azure Blob Storage
DatabaseAmazon Relational Database Service (RDS)Azure SQL Database
Hybrid CloudAWS OutpostsAzure Arc
Pricing modelPay-as-you-go and reserved instancesPay-as-you-go and reserved instances
Support optionsBasic, Developer, Business, and EnterpriseBasic, Developer, Standard, and Premium

Azure and AWS FAQs

What is cloud computing? 

Cloud computing is the delivery of computing services over the internet, including servers, storage, databases, networking, software, analytics, and intelligence. It allows organizations to use shared computing resources rather than maintaining their own infrastructure.

What are the benefits of using cloud computing?

Some of the benefits of using cloud computing include:

  • Cost savings: Cloud computing eliminates the need for expensive hardware and maintenance.
  • Scalability: Organizations can easily scale their computing resources up or down based on their needs.
  • Accessibility: Cloud computing allows access to data and applications from anywhere with an internet connection.
  • Reliability: Cloud providers typically offer high levels of uptime and resilience.
  • Security: Cloud providers often have robust security measures in place to protect data.

What is AWS? 

AWS (Amazon Web Services) is a cloud computing platform provided by Amazon. It offers a wide range of services, including computing, storage, databases, analytics, networking, mobile, developer tools, and security.

What is Azure? 

Azure is a cloud computing platform provided by Microsoft. It offers similar services to AWS, including computing, storage, databases, networking, developer tools, and security.

How do AWS and Azure compare in terms of pricing? 

Pricing for both AWS and Azure can vary based on usage, but generally, AWS is considered to be slightly more expensive for some services. However, the pricing models and discounts offered by each provider can be complex, so it’s important to compare specific services and usage patterns to determine which provider offers the best value.

How do AWS and Azure compare in terms of features and functionality? 

AWS and Azure offer many similar services, but there are some differences in their offerings. For example, AWS has a wider range of services overall, while Azure has more specialized services for certain industries, such as healthcare and government.

How do AWS and Azure compare in terms of uptime and resilience? 

Both AWS and Azure have high levels of uptime and resilience, but there are some differences in their approaches to these areas. AWS typically uses a global network of data centers and multiple availability zones to provide high availability and resilience, while Azure uses a similar approach with its own global network of data centers and availability zones.

In the next blog post in this series, I will delve deeper in to AWS and Azure around the best practices for each vendor and how to ensure the uptime of your Virtual Machines, and since you are here dont forget to check out just some of our software designed specifically for Azure.

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