Arcfra Active-Active Cluster Best Practice: Network Design, Deployment and Capacity Planning | Free Download

Successful active-active data center construction depends on more than enabling a cluster feature. Network topology, cross-site latency, witness node placement, failover capacity, and workload distribution all influence whether an active-active cluster can meet its availability and recovery objectives.

Arcfra has published the Arcfra Active-Active Cluster Best Practice to help infrastructure architects and IT operations teams make these decisions with greater confidence. This complements the official guide for building active-active clusters based on Arcfra AECP, with detailed suggestions on network design, witness node installation, and capacity planning & resource allocation.

What’s Inside the Guide

The guide brings practical experience from real-world active-active deployments into one reference. It focuses on the implementation details that can affect cluster performance, failover behavior, and operational readiness.

Network Design

Network architecture forms the foundation of an active-active cluster. The guide explains how to plan the network for Primary Availability Zone, Secondary Availability Zone, and independent Witness site, along with the bandwidth, latency, connectivity, and routing requirements for each network.

We also introduce two common design options:

• VXLAN overlay with a dedicated storage interconnect, which separates storage traffic from the overlay and supports flexible multi-site networking.
• Full direct dark fiber interconnect, which extends management, business, and storage networks across sites through direct physical links.

The guide outlines the advantages and considerations of each approach, including Layer 2 connectivity, gateway redundancy, split-brain prevention, and the relationship between inter-site storage bandwidth and write throughput.

Witness Node Installation

An independent witness node helps the cluster make reliable quorum and failover decisions. The Best Practice guide covers recommended witness node deployment options, including bare-metal servers, on-premises virtual machines, and public cloud instances. It also provides baseline resource recommendations and explains the network configuration requirements for physical and virtual deployments.

There are also several points that can be easy to miss during implementation, such as separating management and storage networks, configuring static routes during cluster initialization, and avoiding unsupported NAT or port-mapping connections between the Witness Node and the cluster storage networks.

Capacity Planning & Resource Allocation

An active-active cluster must account for the loss of an entire Availability Zone, not only the failure of an individual host. This changes how teams calculate CPU, memory, and storage thresholds before deployment.

The guide provides a practical framework for maintaining failover headroom and planning replica capacity. It also explains how VM Placement Group Rules and anti-affinity policies can distribute redundant application components across Availability Zones.

Download the Best Practice for Free

Active-active infrastructure requires coordinated decisions across network architecture, Witness Node deployment, and resource planning. A design that overlooks any one of these areas can affect failover reliability, application performance, or recovery readiness.

Download the Arcfra Active-Active Cluster Best Practice for practical recommendations, architecture options, deployment considerations, and capacity-planning guidance.

Recommended Readings:

How to Build a Three-Tier Active-Active Data Center with Arcfra AECP?