Load Balancer
Load balancers explained — L4 vs L7, OSI layers, pass-through vs proxy mode, algorithms, and TCP/TLS termination.
Load Balancer
10k request/sec
50k request/sec
70k request/sec
Presentation Layer
Session Layer
Transport Layer (4)
Network Layer
DataLink Layer
Physical Layer
Application Layer (7)
Enable Communication via Protocol
Translate Compress Encrypt the Data
Manage Session/ Connection
Ensure Reliable Data Delivery
Route Data Between Devices
Transfer Frames Over Link
Transmit bits over medium
A load balancer is a system that receives traffic from clients and distributes that traffic across multiple backend servers.
Its goals are usually: Prevent one server from receiving all traffic. Improve availability when a server fails. Allow servers to be added or removed. Provide one stable address to clients.
Load Balancers Based on OSI Layers
1. Source - Destination - IP 2. Ports (80, 443 , 3306) 3. TCP/UDP 4. Connection state and packet-level information
Network Load Balancer
1. Full URL PATH + Parameters 2. HTTP - Methods 3. Auth Tokens 4. Microservices