Azure Red Hat OpenShift (ARO) is a fully managed Red Hat OpenShift service on Azure. We are excited to announce two significant enhancements to ARO’s capabilities:

The ability to configure multiple IP addresses per cluster load balancer is now generally available.
ARO clusters can now scale up to 250 worker nodes.

Previously, ARO clusters were limited to 62 worker nodes due to having only one IP (Internet Protocol) address associated with the cluster’s load balancer. By enabling multiple IP addresses for the load balancer, we have removed this bottleneck, offering organizations greater flexibility in expanding their deployments.

These enhancements significantly improve the scalability and adaptability of ARO public clusters, empowering organizations to scale their infrastructure more effectively. Our goal is to support even larger clusters, providing robust solutions for enterprises with extensive computational requirements. In this blog post, we will delve into the specifics of deploying large ARO clusters, explore a real-world use case, and provide essential information to help you get started with this powerful new capability.

Deploying Large-Scale ARO Clusters

For clusters with over 101 nodes, we recommend using the following control plane nodes (or similar, newer generation instance types):

Standard_D32s_v3
Standard_D32s_v4
Standard_D32s_v5

Here is a sample Azure CLI (command-line interfaces) command to deploy a cluster with Standard_D32s_v5 as the control plane nodes:

Deploying Infrastructure Nodes

For clusters with over 101 nodes, infrastructure nodes are required to separate cluster workloads (such as Prometheus) to minimize contention with other workloads. We recommend deploying three (3) infrastructure nodes per cluster for redundancy and scalability needs.

Recommended instance types for infrastructure nodes:

Standard_E16as_v5
Standard_E16s_v5

For detailed instructions on configuring infrastructure nodes, see Deploy infrastructure nodes in an Azure Red Hat OpenShift (ARO) cluster.

For detailed guidance on deploying large Azure Red Hat OpenShift cluster, see Deploy a large Azure Red Hat OpenShift cluster – Azure Red Hat OpenShift | Microsoft Learn

Adding IP Addresses to the Cluster

A maximum of 20 IP addresses can be added to a load balancer. One (1) IP address is needed per 65 nodes, so a cluster with 250 nodes requires a minimum of four (4) IP addresses.

To add IP addresses to the load balancer using Azure CLI, run the following command:

Alternatively, you can add IP addresses through a REST (Representational State Transfer) API (Application Programming Interfaces) (Application Programming Interfaces) call:

Caution: Before deleting a large cluster, the cluster to 120 nodes or below.

A preview of the CLI is available to use this feature until the official CLI release is made available. For guidance on how to download and install the wheel extension file for this preview CLI, please refer to the documentation.

The power of 250 nodes

Traditionally, ARO public clusters were created with a public load balancer featuring a single public IP address for outbound connectivity. While this configuration worked well for many scenarios, it limited the maximum node count to 62. Now, with the ability to assign multiple additional public IP addresses to the load balancer, you can scale your cluster to the maximum supported number of nodes, unlocking new possibilities for your applications.

Key Features

Scale up to 20 IP addresses per cluster load balancer
Automatically adjusted outbound rules and frontend IP configurations
Increased maximum node count to 250 per cluster
Enhanced overall cluster scalability and performance

Use Case: High-Traffic E-Commerce Platform

Consider an e-commerce company, MegaShop, experiencing rapid growth. They have been running their platform on an ARO cluster but are approaching the 62-node limit. With the holiday season approaching, they need to scale up significantly to handle the expected traffic surge.

By implementing multiple IP addresses on their ARO cluster load balancer, MegaShop can:

Scale beyond the previous 62-node limit
Ensure smooth operations during peak traffic periods
Maintain high availability and performance for their customers

MegaShop’s DevOps team can easily update their existing cluster to use, for example, 10 IP addresses:

This simple change allows MegaShop to confidently scale their infrastructure to meet holiday demand without worrying about outbound connectivity bottlenecks.

Conclusion

The General availability of multiple IP addresses configuration for ARO cluster load balancer empowers organizations to build and scale robust, enterprise-grade Kubernetes environments on Azure with greater flexibility than ever before.

Whether you are running a high-traffic e-commerce site, a data-intensive analytics platform, or any other scalable application, this new capability ensures that your ARO infrastructure can grow alongside your business needs.

Getting Started

New customers can get started by:

Setting up an Azure subscription
Installing the Azure CLI
Creating a new ARO cluster with the desired number of IP addresses

For more detailed information, best practices, and troubleshooting guides, visit the official Azure Red Hat OpenShift documentation and the Red Hat OpenShift documentation.

Embrace the power of scalability and take your ARO deployments to new heights with multiple IP addresses for your cluster load balancers!

Additional Resources

Getting Started with ARO
Red Hat OpenShift Kubernetes
OpenShift vs Kubernetes: What’s the Difference?
eBook: Getting started with Azure Red Hat OpenShift
Azure Red Hat OpenShift Workshop
Azure Red Hat OpenShift Learning Path
Azure Red Hat OpenShift Learning Hub
The TEI (Total Economic Impact) of Azure Red Hat OpenShift

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