Most organisations have services in multiple clouds. You've got services in Azure, maybe some workloads in AWS from an acquisition, Kubernetes running on-premises for data residency reasons. Azure Arc is Microsoft's response to this reality. Instead of giving up on unified management, Arc brings all those resources into Azure so you can govern them from one place. By mid-2022, it's clear that if you're hybrid or multi-cloud and already invested in Azure, Arc is how you stay sane.
Azure Arc projects non-Azure resources into Azure Resource Manager. On-premises servers, AWS EC2 instances, GCP VMs, and Kubernetes clusters become objects in Azure that can be managed with the same tools as native Azure resources. Azure Policy applies to Arc-enabled servers. Microsoft Defender for Cloud monitors them. The Azure portal shows them alongside Azure-native resources.
Organisations often start with a small pilot project, like onboarding a few on-premises servers to Arc. For example, I worked with a customer who started with 20 Arc-enabled servers, which took about 2 weeks to set up. They used Azure Policy to enforce compliance and Microsoft Defender for Cloud for security monitoring. The customer saw immediate benefits in terms of unified management and cost savings from reduced tool sprawl.
With Arc-enabled Kubernetes clusters, you can apply GitOps configurations from Azure, regardless of where they run. A Flux configuration applied in the Azure portal deploys to on-premises clusters the same way as to AKS clusters. Azure Policy for Kubernetes applies to Arc-enabled clusters using the same Gatekeeper-based mechanism as AKS. For organisations with on-premises Kubernetes, Arc for Kubernetes provides consistent policy enforcement across cloud and on-premises.
When deploying Arc-enabled Data Services, organisations need to consider the infrastructure requirements. For example, Azure SQL Managed Instance on Arc requires a minimum of 4 CPU cores and 16 GB of RAM per node. PostgreSQL Hyperscale requires at least 2 CPU cores and 8 GB of RAM. These requirements impact the underlying Kubernetes cluster's infrastructure planning and costs. Additionally, data services on Arc have a 10-20% performance overhead compared to native Azure services, which needs to be factored into capacity planning.
For CIOs with existing AWS or GCP investments alongside Azure, Arc offers a single management plane. Competing products like AWS Systems Manager for hybrid and GCP Anthos for multi-cloud offer similar architectures. The decision often comes down to which cloud the organisation's primary identity and governance investment is in. Arc is the right choice when Azure AD and Azure Policy are the organisational standard.
Organisations with workloads spanning Azure, AWS, GCP, and on-premises use Arc to manage them from one place. The adoption pattern is clear by mid-2022. In one case, a large financial institution used Arc to manage 1000s of resources across multiple clouds, reducing their operational costs by 30% and improving compliance posture.
Arc enables organisations to govern resources from one place, which is essential for maintaining consistency and reducing complexity.
The ability to apply Azure Policy and Microsoft Defender for Cloud to Arc-enabled servers provides an additional layer of security and compliance.