What is failover?

Failover is a high-availability strategy in IT and networking that enables systems, applications, or services to automatically switch to a redundant or standby system when the primary system fails or becomes unavailable. The goal of failover is to minimize downtime, maintain business continuity, and ensure uninterrupted service in the event of hardware failure, software crash, or other system disruption.

Failover systems are essential in environments where availability, performance, and reliability are mission-critical, such as data centers, cloud infrastructure, managed IT environments, and enterprise networks.  

What is a failover system?

A failover system is a configuration that includes at least one primary system and one or more continuously monitored standby systems. If the primary system fails, the failover mechanism automatically redirects processes, services, or traffic to the backup system, eliminating the need for manual intervention.

Failover can be implemented at multiple layers:

• Server-level failover: A standby server takes over application or database workloads.
• Network failover: Network traffic is rerouted through a secondary connection or router.
• Storage failover: Backup storage devices are activated when primary storage is unreachable.
• Cloud and virtual failover: Workloads shift to backup instances or environments in the cloud.  

How does failover work?

Think of failover like a backup generator for your IT systems. When the power (primary server or network) goes out, the generator (backup system) immediately turns on, keeping operations running without noticeable interruption.

Failover systems rely on:

• Monitoring tools: To continuously check the health of the primary system.
• Alerting mechanisms: To detect if the primary system becomes unresponsive.
• Failover logic or orchestration: To initiate a switchover when failure conditions are met.
• Redundant infrastructure: Standby systems that mirror or replicate the primary system’s data or configuration.

Common failover scenarios include:

• A production database server crashes, and traffic is redirected to a secondary replicated server within seconds.
• An internet connection fails at a branch office, and traffic is automatically routed through a backup ISP connection.
• A virtual machine host fails, triggering a failover to a live VM in a different availability zone.  

Benefits of failover for IT and security teams

High availability and reduced downtime

Failover ensures continuous access to services and applications, even in the event of hardware failures, power outages, or network issues.

• Keep mission-critical systems online 24/7.
• Prevent productivity losses and missed revenue.
• Meet or exceed uptime targets and SLAs.

Fast recovery without manual intervention

Failover systems are designed for automated switchover, allowing for faster recovery than manual recovery processes.

• Eliminate the need for human decision-making in time-sensitive situations.
• Trigger failover instantly via health checks or failure alerts.
• Resume operations with minimal interruption.

Seamless business continuity

When integrated into your BCDR strategy, failover:

• Reduces the impact of outages on customers and partners.
• Supports cloud or hybrid BCDR strategies.
• Allows recovery testing without taking systems offline.

Improved compliance and risk management

Failover capabilities help organizations satisfy the availability and resilience requirements for industry and regulatory compliance for sectors such as:

• HIPAA (healthcare)
• PCI-DSS (payment processing)
• ISO 27001 (information security)
• SOC 2 (service organizations)
• NIST 800-34 (and other BCDR standards)

Infrastructure resilience

Failover is key to building resilient systems that can recover quickly and scale dynamically:

• Supports load balancing and distributed deployments.
• Enables multi-region or hybrid cloud architectures.
• Reduces reliance on single points of failure.  

Who needs failover?

Failover is a foundational strategy for ensuring business continuity and business resilience.  Below are the key benefits broken out by team type. 

IT departments and enterprises

• Protect uptime for mission-critical services like email, databases, and file systems.
• Ensure 24/7 access to internal systems for global teams.
• Lower the risk of costly outages that affect productivity, customer service, or revenue.
• Comply with SLAs and business continuity planning requirements.

Cybersecurity and infrastructure teams

• Enable secure failover of firewalls, VPNs, and intrusion prevention systems.
• Support disaster recovery strategies for ransomware or DDoS attacks.
• Protect continuous security monitoring and logging for compliance audits.
• Maintain visibility into traffic and threat activity during switchover events to ensure seamless operations.

Managed service providers (MSPs)

• Offer always-on business continuity and disaster recovery (BCDR) as part of a bundled services strategy that secures clients with modern data protection.
• Minimize client downtime by quickly switching over to the secondary infrastructure.
• Meet competitive SLAs with optimized recovery time objectives (RTOs) and recovery point objectives (RPOs) by automating service recovery.
• Reduce support tickets and incident response through reliable automation.

Small and midsize businesses (SMBs)

• Avoid downtime caused by internet or system outages that can stall operations.
• Quickly restore apps and files to sustain productivity and service delivery.
• Meet cyber insurance and regulatory requirements for backups, business continuity, and disaster recovery.
• Ensure the availability of customer-facing portals or services to protect the business reputation.