Elastic Load Balancing plays a key role in today's cloud computing. It has an impact on how incoming traffic is distributed across different servers or resources. This leads to better availability, reliability, and performance for apps running on AWS, Azure, and GCP.
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How does Elastic Load Balancing work?
Elastic Load Balancing splits up network or app traffic among many targets. These can be virtual machines, containers, or IP addresses. It does this on its own. It stops one resource from becoming a problem. This helps keep things running and makes users happy. AWS, Azure, and GCP each have their take on Elastic Load Balancing. Each one has its strong points.
Key Benefits of Elastic Load Balancing
- High Availability: It keeps apps running by sending traffic elsewhere if a server stops working.
- Scalability: It changes to handle traffic shifts, whether it goes up or down.
- Fault Tolerance: It sends traffic to resources that are working well.
- Security: It works with SSL/TLS endpoints and can use security rules.
Types of Elastic Load Balancers
- Application Load Balancer (Layer 7)
Directs traffic based on content such as URLs or headers.
Works best with web apps and microservices. - Network Load Balancer (Layer 4)
Handles TCP/UDP traffic with very quick response times.
Suits high-performance and real-time scenarios well. - Classic Load Balancer (AWS)
Offers ongoing support for Layer 4 and Layer 7.
Fits legacy apps the best. - Internal Load Balancer
Manages traffic in a private network away from direct internet exposure.
How Elastic Load Balancing Works
- Client Request: Users send requests to the app.
- Listener: The load balancer waits for requests on a specific port and protocol.
- Health Check: The system allows healthy targets to get traffic.
- Traffic Routing: Healthy backends receive requests from the load balancer.
- Response: Backends process requests and send answers back to users.
Elastic Load Balancing Across Providers
| Feature/Provider | AWS Elastic Load Balancing | Azure Load Balancer & Application Gateway | GCP Load Balancing |
| Types | Application, Network, Classic | Basic, Standard, Application Gateway | HTTP(S), TCP/UDP, SSL Proxy |
| Layer Supported | 4 & 7 | 4 (LB), 7 (App Gateway) | 4 & 7 |
| Autoscaling | Yes | Yes | Yes |
| Global Load Balancing | Yes (Global Accelerator) | Yes (Traffic Manager, Front Door) | Yes (Global HTTP(S) LB) |
| SSL Termination | Yes | Yes | Yes |
| Health Checks | Yes | Yes | Yes |
| Integration | EC2, ECS, Lambda, IPs | VMs, VMSS, App Services | Compute Engine, GKE, Cloud Run |
Common Terms in Elastic Load Balancing
- Listener: The starting point for client requests, which a protocol and port define.
- Target Group / Backend Pool: A set of resources that take in traffic.
- Session Persistence (Sticky Sessions): Keeps a user's session on the same backend.
- SSL Offloading: Takes the job of decrypting SSL traffic off the backend, cutting down its workload.
- Cross-Zone Load Balancing: Spreads traffic across all backend resources in every zone.
Best Practices
- Enable health checks to direct traffic to resources in good condition.
- Use autoscaling to adjust based on demand.
- Apply SSL termination to handle secure traffic.
- Keep an eye on and record data for performance and fixing issues.
- Put global load balancing to use in setups across multiple regions.
Use Cases
- Web Applications: Handles large amounts of HTTP/HTTPS traffic.
- APIs: Protects and oversees API endpoints.
- Microservices: Directs traffic between services within the system.
- Hybrid Cloud: Oversees traffic moving between on-site systems and the cloud.
Quick Reference Table
| Term | Description |
| Elastic Load Balancing | Distributes traffic across multiple resources |
| Listener | Entry point for client requests (protocol/port) |
| Health Check | Monitors resource health for availability |
| Target Group/Backend Pool | Collection of resources receiving traffic |
| SSL Offloading | Decrypts SSL at the load balancer |
| Autoscaling | Adjusts resources based on demand |
Elastic Load Balancing is crucial to creating well-built, highly scalable, and secure cloud applications. Knowing its features and best practices will allow you to guarantee your applications operate smoothly on AWS, Azure, and GCP.
