HIGH AVAILABILITY NETWORK INFRASTRUCTURE

High availability, fault tolerance and disaster recovery are important things to consider when designing a system. These terms are sometimes used interchangeably by architects and developers. They are not, however, the same thing – and understanding the differences can save you many headaches, as well as time and money. I will go through the differences between the three terms and explain how you can implement them in AWS.

High Availability (HA) is essential for maintaining continuous system performance, ensuring minimal downtime, and delivering services without interruption. Achieving this requires careful planning, implementation of redundancy, and failover mechanisms to ensure that systems remain operational even when components fail.

3 Major Principles that Ensure High Availability:

1. Elimination of Single Points of Failure (SPOF): A Single Point of Failure occurs when one component's failure results in the entire system's failure. To prevent this, critical components of the system should be duplicated, ensuring that if one part fails, a backup or secondary system can immediately take over without affecting operations.

2. Reliable Crossover: This principle refers to the seamless switching between redundant systems or components. For example, if one server or data center experiences an issue, traffic can be rerouted to a healthy server or data center without disrupting the user experience. This requires robust load balancing and failover systems.

3. Detection of Failures as They Occur: For a system to remain highly available, it must be capable of quickly detecting when a failure occurs. This allows for automatic recovery or failover before the user or organization experiences any noticeable impact. Monitoring tools, automated alerts, and real-time reporting are essential for this process.

Strategies for Achieving High Availability:

• Redundancy and Replication: By replicating critical system components, you ensure that even if one system fails, another is available to handle the load. This can include redundant servers, power supplies, and network links.

• Automatic Failover and Load Balancing: Automated failover mechanisms ensure that traffic or services are redirected to a healthy component when one fails. Load balancing helps distribute traffic evenly across available systems, ensuring no single server or resource becomes overwhelmed.

• Geographical Redundancy: To protect against site-wide disasters (e.g., natural disasters, power failures), systems should be replicated in geographically diverse data centers or cloud providers. This ensures that even if one data center becomes unavailable, another can immediately take over. Brookside’s High Availability Network: Brookside’s approach to high availability is designed to minimize downtime by incorporating multiple redundancy and failover strategies. Some of their key features include:

• Multiple Fiber Carriers Over Managed SD-WAN with Automatic Failover: By using multiple fiber carriers, Brookside ensures that if one carrier fails, traffic is automatically routed through an alternative path without impacting the service. This is enhanced by SD-WAN (Software-Defined Wide Area Network), which allows for intelligent routing and failover.

• Multiple Cloud-Based Providers: Brookside leverages multiple cloud providers, ensuring that if one cloud provider experiences an outage, services are automatically transferred to another provider. This helps prevent downtime from affecting operations.

In summary, high availability requires a combination of redundancy, real-time failure detection, and rapid failover systems. By implementing these strategies, organizations can ensure that their systems remain reliable and accessible, even in the face of failures or disruptions.