Multi-Site Failover

Introduction

The Multi-Site Failover setup ensures data protection and availability by replicating data from a primary site to two additional sites. This configuration provides multiple failover options to maintain access to data in case of site outages.

This document provides clear instructions for setting up Multi-Site Failover replication. It is designed to help you implement the process step-by-step, ensuring reliable data failover and recovery between the clusters involved.

The highest level of data protection comes from multi-site replication, where a source cluster's data is replicated to clusters at 2 different sites. Typically, 2 clusters are in a metro location and the third cluster is outside a power grid failure zone.

The goal of this failover design is to provide a choice of sites to fail over to and to have fully automated failover between sites. In addition, failback and failover again to the same or a different site is possible, but may require some manual steps to avoid SyncIQ policies that block the failover.

In this configuration, Eyeglass can be used with the Access Zone failover solution to protect the data in an Access Zone and allow a failover choice of target cluster 1 or target cluster 2 (at the third site). This solution operates at the Access Zone level and allows one or more Access Zones to be 3-site protected and other Access Zones to be only 2-site protected.

This solution supports fully automated Access Zone failover and DFS Type multi-site failover and failback. Access Zone and DFS Type configuration are covered in separate sections.

Prerequisites

To successfully implement a Multi-Site Failover setup, the following prerequisites must be met:

1. DNS Configuration

   • Create triple Name Server (NS) delegation records.
   • Ensure NS records point to the Subnet Service IPs of each cluster and subnet participating in the failover process.

2. Eyeglass Hints (igls-hints)

   • Configure unique igls-hints on all three clusters for each Access Zone.
   • These hints map IP pools and SmartConnect names during failover.

3. SmartConnect Zone Placeholders

   • On the target clusters, set up SmartConnect zone placeholders using the naming convention:
     igls-original-<SmartConnect Zone name on source cluster>.
   • This ensures consistent network configuration during failover.

4. Replication Policies

   • Implement overlapping source path replication policies.
   • Configure data replication from the primary cluster (Site A) to both secondary clusters (Sites B and C).

5. Active Directory (AD) Configuration

   • Ensure all clusters use the same AD provider within a single AD forest.
   • Extend AD delegation to the third cluster, granting each cluster write permissions to its own computer account and the computer accounts of the other two clusters.

Supported Access Zone Failover Operations

• A to B or A to C.
• If B is the active cluster:
  • A to C Access Zone failover is not supported.
  • A to C per SyncIQ Policy failover is supported (manual steps for networking).
• If C is the active cluster:
  • A to B Access Zone failover is not supported.
  • A to B per SyncIQ Policy failover is supported (manual steps for networking).

Logical Diagrams for Multi-Site Failover

Logical diagrams are available to provide a clearer understanding of the Multi-Site Failover configuration. These resources visually represent the relationships between the primary and secondary sites, detailing how data flows between clusters and how failover mechanisms operate. A dedicated document, linked to below, offers comprehensive diagrams and step-by-step workflows that cover critical aspects of the setup, including:

• Three-Site Replication Pathways: Illustrating data replication from the primary site to two secondary sites.
• Failover and Failback Processes: Outlining the sequence of actions taken during site outages and recovery.
• DNS and Active Directory Integration: Explaining how these elements are configured to maintain seamless functionality during failover events.

These visual aids provide a detailed representation of the architecture and mechanics of Multi-Site Failover, supporting implementation and troubleshooting.

Logical Diagrams for Multi-Site Failover

View detailed logical diagrams and workflows for Multi-Site Failover, including replication configurations, failover sequences, and network integration steps.

View Diagrams

Once you’ve reviewed the diagrams, proceed to the next step to configure Access Zone Failover SyncIQ for your three-site environment.

Access Zone Failover SyncIQ Config for 3 Site

Configuring Access Zone Failover with SyncIQ across three sites ensures robust data replication and high availability. This setup allows for flexible failover options between multiple clusters, enhancing disaster recovery capabilities.

For instructions and best practices on setting up Access Zone Failover with SyncIQ in a multi_site configuration, please refer to the detailed guide linked below.

Access Zone Failover SyncIQ Configuration Guide

Detailed steps and considerations for configuring Access Zone Failover with SyncIQ across three sites, including prerequisites and procedural guidelines.

View Guide

DFS Type Failover Configuration for 3 Site

For a guide on configuring and managing DFS Type Failover in a multi-site setup, including step-by-step procedures for failover and failback, refer to the following article:

Multi-Site DFS Type Failover

Explore detailed steps and best practices for configuring DFS Type Failover in a 3-site environment, including initial setup, failover, and failback processes.

View Guide

See Also

For more guidance related to individual failover methods, refer to the articles on AZ Failover Configuration, Policy Failover Configuration, and DFS Failover Configuration.