What is a load balancer?
🧐 This is a brief and easy to understand overview. Serious candidates should research the crucial details after reading this explanation.
🌐 The main purpose of a load balancer is to make sure no single server on multi-network server system receives too many requests.
⚖️ It quite literally balances your server clusters.
How Data Gets to it's destination
This is how the data flow goes:
- Computer(Client) using your application sends a request to your server.
- Request gets routed to your load balancer first.
👮♂️ Think of a load balancer as a traffic cop at a street light.
🫸 He tells you to stop
👋or waves you on by in a certain direction when they identified it's safe for you to proceed.
↔️ (In a "no load balancer" system, usually it gets routed straight to the server.) - Your load balancer receives the request then:
📊 Checks Server Health and identifies the most suitable available server.
↩️ If a server goes down or becomes unresponsive, the load balancer can redirect the traffic to other servers that are functioning normally.
📈 Request gets routed to this "optimal" server. This creates high availability and optimal performance for your systems(application).
🏋 Some load balancers can handle an intense tasks know as SSL/TLS encryption and decryption. This removes this part of the process from the servers themselves and places this heavy task on the load balancer.
✅ You will see better performance, scalability, failure handling, prevent bottlenecks, efficient resource use, and session persistence by implementing a load balancer.
Challenges
🔴 Here are some of the challenges:
- Single Point of Failure: If the load balancer goes down itself, there needs to be a backup or your system loses this capability.
- Cost and Complexity
- Configuration Issues
- Extra Overhead
- SSL Management(SSL/TLS mentioned previously)
❗ If you don't have a load balancer you may see a single point of failure, overloaded servers, or limited scalability.
Detailed Readings and Helpful Concepts to Know
🟩 To read a detailed version of a load balancer, check out this resource by GeeksforGeeks: GeeksforGeeks Load Balancer Article
📚 If you're not familiar with horizontal scaling, this easy "Vertical vs Horizontal Scaling" guide I created will help improve your understanding: Vertical vs Horizontal Scaling Guide
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