🔹 Static Algorithms
1. Round robin The client requests are sent to different service instances in sequential order. The services are usually required to be stateless.
2. Sticky round-robin This is an improvement of the round-robin algorithm. If Alice’s first request goes to service A, the following requests go to service A as well.
3. Weighted round-robin The admin can specify the weight for each service. The ones with a higher weight handle more requests than others.
4. Hash This algorithm applies a hash function on the incoming requests’ IP or URL. The requests are routed to relevant instances based on the hash function result.
🔹 Dynamic Algorithms
5. Least connections A new request is sent to the service instance with the least concurrent connections.
6. Least response time A new request is sent to the service instance with the fastest response time.