Designing for High Availability: Building Resilient Systems
In today's digital era, ensuring your application is highly available is crucial for maintaining user satisfaction and trust. Downtime can lead to lost revenue, brand damage, and customer frustration. In this blog, we'll explore the key aspects of designing highly available systems
Load Balancing: Efficiently Distributing Traffic
1️⃣ Round Robin - Requests are distributed evenly across all available servers in a cyclic manner.
2️⃣ Least Connections - Directs traffic to the server with the least number of active connections.
3️⃣ IP Hash - Maps a client's IP address to a specific server, ensuring session persistence.
Why it matters: Effective load balancing helps maximize throughput, minimize response times, and prevent server overload.
Redundancy: Building in Extra Capacity
Server redundancy: Duplicate servers ensure that if one fails, the other can take over without disrupting the service.
Network redundancy: Multiple network paths protect against failures in network components.
Power redundancy: Backup power systems, such as UPS and generators, keep your servers up and running during power outages.
Why it matters: Redundancy is essential for fault tolerance and minimizing the impact of component failures.
Data Replication: Ensuring Data Consistency
Synchronous replication: Data is written to the primary and secondary nodes simultaneously, ensuring data consistency but increasing write latency.
Asynchronous replication: Data is written to the primary node first, then propagated to the secondary node, offering lower latency but with a risk of data loss.
Why it matters: Data replication strategies ensure that your system can continue functioning even when a data storage node goes down.
Automatic Failover: Switching to Backup Systems
🔄 Active-standby: A primary system handles all requests, while a backup system is kept idle, ready to take over in case of failure.
🔄 Active-active: Multiple systems work simultaneously, sharing the load, and any failed system is automatically replaced by a healthy one.
Why it matters: Automatic failover ensures that your service remains operational in the face of system failures.
Conclusion
Designing for high availability is essential to ensure the continuous operation of your application. By incorporating load balancing, redundancy, data replication, automatic failover, and monitoring, you can build resilient systems that keep your users happy even when the unexpected occurs.