Load Balancing
Distributing incoming network traffic across multiple servers to ensure no single server becomes overwhelmed, improving application availability, reliability, and performance.
In-Depth Explanation
Load balancing distributes incoming traffic across multiple servers (or backend resources) to ensure no single server is overwhelmed. It improves application availability, reliability, and responsiveness by spreading the workload evenly.
Load balancing algorithms:
- Round robin: Distributes requests sequentially across servers
- Least connections: Sends to the server with fewest active connections
- Weighted: Distributes based on server capacity weights
- IP hash: Routes based on client IP (session persistence)
- Least response time: Sends to the fastest-responding server
Types of load balancers:
- Application Load Balancer (Layer 7): HTTP/HTTPS routing based on content
- Network Load Balancer (Layer 4): TCP/UDP routing based on IP and port
- Global Load Balancer: Distributes across geographic regions
- DNS-based: Load balancing through DNS resolution
- Software: Nginx, HAProxy running on servers
Cloud load balancing services:
- AWS: Application Load Balancer (ALB), Network Load Balancer (NLB)
- Azure: Azure Load Balancer, Application Gateway
- Google Cloud: Cloud Load Balancing
- Cloudflare: Load Balancing with health checks
Load balancing features:
- Health checks: Monitoring server health and routing away from unhealthy servers
- SSL termination: Handling SSL/TLS at the load balancer
- Session persistence: Routing returning users to the same server
- Auto-scaling integration: Adding/removing servers based on demand
- WAF integration: Web application firewall at the load balancer
Load balancing benefits:
- Eliminates single points of failure
- Enables horizontal scaling
- Improves response times through optimal server selection
- Provides graceful handling of server failures
- Enables zero-downtime deployments
Business Context
Load balancing ensures applications remain available and responsive even during traffic spikes, preventing the revenue-damaging outages that occur when a single server is overwhelmed during peak periods or marketing campaigns.
How Clever Ops Uses This
Clever Ops configures load balancing for Australian businesses using cloud-native services. We design load-balanced architectures that handle traffic spikes, eliminate single points of failure, and enable zero-downtime deployments, ensuring applications remain fast and available for Australian users.
Example Use Case
"An Australian e-commerce company implements an AWS Application Load Balancer distributing traffic across 4 web servers with health checks. When one server fails during a sale, traffic automatically redirects to healthy servers with zero customer impact."